View source for Unsolved:Vaccine hesitancy

{{short description|Reluctance or refusal to be vaccinated or have one's children vaccinated}}
{{pp-semi-indef}}

[[File:Anti-vaccination protest near Leicester clock tower, October 2021.jpg|thumb|upright=1.5|An anti-vaccination activist with a misleading claim that children can be effectively protected from disease solely by natural immunity]]
{{Alternative medicine sidebar|conspiracy}}
'''Vaccine hesitancy''' is a delay in acceptance, or refusal, of [[Biology:Vaccine|vaccine]]s despite the availability of vaccine services and supporting evidence. The term covers refusals to vaccinate, delaying vaccines, accepting vaccines but remaining uncertain about their use, or using certain vaccines but not others.<ref>{{cite journal |title=Vaccine hesitancy: a generation at risk |journal=The Lancet |year=2019 |doi=10.1016/S2352-4642(19)30092-6 |last1=The Lancet Child & Adolescent Health |volume=3 |issue=5 |page=281 |pmid=30981382 |s2cid=115201206 |doi-access=free }}</ref><ref name="Smith2015">{{Cite journal |last=Smith |first=MJ |date=November 2015 |title=Promoting Vaccine Confidence |journal=Infectious Disease Clinics of North America |type=Review |volume=29 |issue=4 |pages=759–69 |doi=10.1016/j.idc.2015.07.004 |pmid=26337737}}</ref><ref name="Larson2014">{{Cite journal |last1=Larson |first1=HJ |last2=Jarrett |first2=C |last3=Eckersberger |first3=E |last4=Smith |first4=DM |last5=Paterson |first5=P |date=April 2014 |title=Understanding vaccine hesitancy around vaccines and vaccination from a global perspective: a systematic review of published literature, 2007–2012. |journal=Vaccine |volume=32 |issue=19 |pages=2150–59 |doi=10.1016/j.vaccine.2014.01.081 |pmid=24598724}}</ref><ref>{{cite journal |last1=Cataldi |first1=Jessica |last2=O'Leary |first2=Sean |title=Parental vaccine hesitancy: scope, causes, and potential responses |journal=Current Opinion in Infectious Diseases |date=2021 |volume=34 |issue=5 |pages=519–526 |doi=10.1097/QCO.0000000000000774 |pmid=34524202 |s2cid=237437018 |url=https://journals.lww.com/co-infectiousdiseases/Fulltext/2021/10000/Parental_vaccine_hesitancy__scope,_causes,_and.19.aspx}}</ref> The [[Philosophy:Scientific consensus|scientific consensus]] that vaccines are generally safe and effective is overwhelming.<ref>{{Cite journal|date=October 2017|title=Communicating science-based messages on vaccines|journal=Bulletin of the World Health Organization|volume=95|issue=10|pages=670–71|doi=10.2471/BLT.17.021017|pmc=5689193|pmid=29147039}}</ref><ref>{{Cite news|title=Why do some people oppose vaccination?|work=Vox|url=https://www.vox.com/2018/8/21/17588104/vaccine-opposition-anti-vaxxer|access-date=2018-11-26}}</ref><ref>{{Cite news|last=Ceccarelli|first=Leah|name-list-style=vanc|title=Defending science: How the art of rhetoric can help|language=en|work=The Conversation|url=http://theconversation.com/defending-science-how-the-art-of-rhetoric-can-help-68210|access-date=2018-11-26}}</ref><ref>{{Cite web|last=U.S. Department of Health and Human Services|title=Vaccines.gov|url=https://www.vaccines.gov/basics/safety/index.html|access-date=2018-08-05|website=Vaccines.gov|language=en-us}}</ref> Vaccine hesitancy often results in disease [[Medicine:Outbreak|outbreak]]s and deaths from [[Medicine:Vaccine-preventable diseases|vaccine-preventable diseases]].<ref>{{Cite web|title=Frequently Asked Questions (FAQ)|url=http://www.childrenshospital.org/centers-and-services/division-of-infectious-diseases/faq-resurgence-of-measles|archive-url=https://web.archive.org/web/20131017113035/http://www.childrenshospital.org/centers-and-services/division-of-infectious-diseases/faq-resurgence-of-measles|archive-date=October 17, 2013|access-date=February 11, 2014|website=Boston Children's Hospital}}</ref><ref name="auto1">{{Cite journal|vauthors=Phadke VK, Bednarczyk RA, Salmon DA, Omer SB|date=March 2016|title=Association Between Vaccine Refusal and Vaccine Preventable Diseases in the United States: A Review of Measles and Pertussis|journal=JAMA|volume=315|issue=11|pages=1149–58|doi=10.1001/jama.2016.1353|pmc=5007135|pmid=26978210}}</ref><ref name="wolfesharp" /><ref name="AgeOld">{{Cite journal|vauthors=Poland GA, Jacobson RM|date=13 January 2011|title=The age-old struggle against the antivaccinationists|journal=The New England Journal of Medicine|volume=364|issue=2|pages=97–99|doi=10.1056/NEJMp1010594|pmid=21226573|s2cid=39229852}}</ref><ref>{{Cite magazine|last=Wallace A|date=2009-10-19|title=An epidemic of fear: how panicked parents skipping shots endangers us all|url=https://www.wired.com/magazine/2009/10/ff_waronscience/all/1|magazine=Wired|access-date=2009-10-21}}</ref><ref>{{Cite journal|vauthors=Poland GA, Jacobson RM|date=March 2001|title=Understanding those who do not understand: a brief review of the anti-vaccine movement|journal=Vaccine|volume=19|issue=17–19|pages=2440–45|doi=10.1016/S0264-410X(00)00469-2|pmid=11257375|s2cid=1978650 }}</ref> Therefore, the [[Organization:World Health Organization|World Health Organization]] characterizes vaccine hesitancy as one of the top ten global health threats.<ref>{{Cite web|title=Ten threats to global health in 2019|url=http://www.who.int/emergencies/ten-threats-to-global-health-in-2019|url-status=dead|archive-url=https://web.archive.org/web/20190627025209/http://www.who.int/emergencies/ten-threats-to-global-health-in-2019|archive-date=2019-06-27|access-date=2020-12-09|website=Who.int|language=en}}</ref><ref>{{Cite news|last=PM|first=Aristos Georgiou|date=2019-01-15|title=The anti-vax movement has been listed by WHO as one of its top 10 health threats for 2019|language=en|url=https://www.newsweek.com/world-health-organization-who-un-global-health-air-pollution-anti-vaxxers-1292493|access-date=2019-01-16}}</ref>

Vaccine hesitancy is complex and context-specific, varying across time, place and vaccines.<ref>{{Cite web|last=SAGE|first=Working Group|date=1 October 2014|title=Report of the SAGE working group on vaccine hesitancy|url=https://www.who.int/immunization/sage/meetings/2014/october/1_Report_WORKING_GROUP_vaccine_hesitancy_final.pdf|website=WHO}}</ref> It can be influenced by factors such as lack of proper scientifically based knowledge and understanding about how vaccines are made or work, as well as psychological factors including fear of needles<ref name="Smith2015" /> and distrust of public authorities, a person's lack of confidence (mistrust of the vaccine and/or healthcare provider), complacency (the person does not see a need for the vaccine or does not see the value of the vaccine), and convenience (access to vaccines).<ref name="Larson2014" /> It has existed since the invention of vaccination and pre-dates the coining of the terms "vaccine" and "vaccination" by nearly eighty years.<ref name="Gerber"/>

"'''Anti-vaccinationism'''" refers to total opposition to vaccination; in more recent years, anti-vaccinationists have been known as "'''anti-vaxxers'''" or "'''anti-vax'''".<ref>{{Cite web |last=Hinsliff |first=Gaby |date=16 November 2020 |title=It's the 'vaccine hesitant', not anti-vaxxers, who are troubling public health experts |website=TheGuardian.com |url=https://www.theguardian.com/commentisfree/2020/nov/16/vaccine-hesitant-anti-vaxxers-public-health-experts-covid}}</ref>  The specific hypotheses raised by anti-vaccination advocates have been found to change over time.<ref name="Gerber"/> [[Unsolved:Anti-vaccine activism|Anti-vaccine activism]] has been increasingly connected to political and economic goals.<ref name="Carpiano">{{cite journal |last1=Carpiano |first1=Richard M |last2=Callaghan |first2=Timothy |last3=DiResta |first3=Renee |last4=Brewer |first4=Noel T |last5=Clinton |first5=Chelsea |last6=Galvani |first6=Alison P |last7=Lakshmanan |first7=Rekha |last8=Parmet |first8=Wendy E |last9=Omer |first9=Saad B |last10=Buttenheim |first10=Alison M |last11=Benjamin |first11=Regina M |last12=Caplan |first12=Arthur |last13=Elharake |first13=Jad A |last14=Flowers |first14=Lisa C |last15=Maldonado |first15=Yvonne A |last16=Mello |first16=Michelle M |last17=Opel |first17=Douglas J |last18=Salmon |first18=Daniel A |last19=Schwartz |first19=Jason L |last20=Sharfstein |first20=Joshua M |last21=Hotez |first21=Peter J |title=Confronting the evolution and expansion of anti-vaccine activism in the USA in the COVID-19 era |journal=Lancet |date=2023 |volume=401 |issue=10380 |pages=967–970 |doi=10.1016/S0140-6736(23)00136-8 |pmid=36871571 |pmc=9981160 |issn=0140-6736}}</ref><ref name="Herasimenka">{{cite journal |last1=Herasimenka |first1=Aliaksandr |last2=Au |first2=Yung |last3=George |first3=Anna |last4=Joynes-Burgess |first4=Kate |last5=Knuutila |first5=Aleksi |last6=Bright |first6=Jonathan |last7=Howard |first7=Philip N |title=The political economy of digital profiteering: communication resource mobilization by anti-vaccination actors |journal=Journal of Communication |date=24 December 2022 |volume=73 |issue=2 |pages=126–137 |doi=10.1093/joc/jqac043 |pmid=37016634 |pmc=10066223 |url=https://doi.org/10.1093/joc/jqac043 |access-date=27 January 2023}}</ref>
Although myths, [[Unsolved:Conspiracy theory|conspiracy theories]], misinformation and disinformation spread by the anti-vaccination movement and [[Fringe science|fringe]] doctors leads to vaccine hesitancy and public debates around the medical, ethical, and legal issues related to vaccines, there is no serious hesitancy or debate within mainstream medical and scientific circles about the benefits of vaccination.<ref name="Dubé">{{cite journal |last1=Dubé |first1=Ève |last2=Ward |first2=Jeremy K. |last3=Verger |first3=Pierre |last4=MacDonald |first4=Noni E. |title=Vaccine Hesitancy, Acceptance, and Anti-Vaccination: Trends and Future Prospects for Public Health |journal=Annual Review of Public Health |date=1 April 2021 |volume=42 |issue=1 |pages=175–191 |doi=10.1146/annurev-publhealth-090419-102240 |pmid=33798403 |s2cid=232774243 |language=en |issn=0163-7525 |quote="the scientific and medical consensus on the benefits of vaccination is clear and unambiguous"|doi-access=free }}</ref>

Proposed laws that mandate vaccination, such as [[Medicine:California Senate Bill 277|California Senate Bill 277]] and Australia's No Jab No Pay, have been opposed by anti-vaccination activists and organizations.<ref>{{Cite news |url=http://discovermagazine.com/2018/dec/fostering-fear |title=The Long History of America's Anti-Vaccination Movement |access-date=2019-02-02 |website=DiscoverMagazine.com}}</ref><ref>{{Cite news |url=https://www.politico.eu/article/how-anti-vax-went-viral/ |title=How anti-vax went viral |last=Young |first=Zachary |date=2018-11-21 |access-date=2019-02-02 |name-list-style=vanc}}</ref><ref>{{Cite news |url=https://www.independent.co.uk/news/world/europe/anti-vaxxers-italy-vaccine-measles-epidemic-europe-us-vaccination-global-health-security-agenda-a8560021.html |title=How the anti-vaxxers are winning in Italy |date=2018-09-28 |access-date=2019-02-02 |language=en}}</ref> Opposition to mandatory vaccination may be based on anti-vaccine sentiment, concern that it violates [[Philosophy:Civil liberties|civil liberties]] or reduces public trust in vaccination, or suspicion of profiteering by the pharmaceutical industry.<ref name="wolfesharp" /><ref>{{Cite web |url=https://www.mystatesman.com/news/state--regional-govt--politics/civil-liberties-center-vaccination-debate-texas/lWzq91qhSyAKcY8MiaWnYM/ |title='Civil liberties' at center of vaccination debate in Texas |last=Chang |first=Julie |date=12 July 2017 |website=Mystatesman |publisher=Austin American-Statesman |name-list-style=vanc |access-date=July 28, 2018 |archive-date=July 13, 2017 |archive-url=https://web.archive.org/web/20170713075809/https://www.mystatesman.com/news/state--regional-govt--politics/civil-liberties-center-vaccination-debate-texas/lWzq91qhSyAKcY8MiaWnYM/ |url-status=dead }}</ref><ref>{{Cite web |url=https://www.nytimes.com/roomfordebate/2014/03/23/making-vaccination-mandatory-for-all-children/in-britain-vaccinate-with-persuasion-not-coercion |title=In Britain, Vaccinate With Persuasion, not Coercion |last1=Elliman |first1=David |last2=Bedford |first2=Helen |date=23 March 2014 |website=The New York Times |name-list-style=vanc}}</ref><ref>{{Cite news |url=https://health.spectator.co.uk/anti-vaxxers-have-embraced-social-media-were-paying-for-fake-news-with-real-lives/ |title=Anti-vaxxers have embraced social media. We're paying for fake news with real lives |date=2017-06-28 |access-date=2019-02-02 |language=en-GB |archive-date=April 5, 2019 |archive-url=https://web.archive.org/web/20190405124330/https://health.spectator.co.uk/anti-vaxxers-have-embraced-social-media-were-paying-for-fake-news-with-real-lives/ |url-status=dead }}</ref><ref>Bourree Lam, [https://www.theatlantic.com/business/archive/2015/02/vaccines-are-profitable-so-what/385214/ Vaccines Are Profitable, So What?]. ''The Atlantic'' Feb. 10, 2015</ref>

==Effectiveness==
[[File:Measles US 1938-2019.png|thumb|upright=1.5 |right |Rates of measles fell sharply when universal immunization was introduced.]]

[[Scientific evidence]] for the effectiveness of large-scale vaccination campaigns is well established.<ref>{{Cite journal |last1=Christenson |first1=Brith |last2=Lundbergh |first2=Per |last3=Hedlund |first3=Jonas |last4=Örtqvist |first4=Åke |date=March 2001 |title=Effects of a large-scale intervention with influenza and 23-valent pneumococcal vaccines in adults aged 65 years or older: a prospective study |journal=The Lancet |volume=357 |issue=9261 |pages=1008–11 |doi=10.1016/S0140-6736(00)04237-9 |pmid=11293594 |s2cid=8125882}}</ref> Two to three million deaths are prevented each year worldwide by vaccination, and an additional 1.5 million deaths could be prevented each year if all recommended vaccines were used.<ref name="Jacobson2020">{{cite journal |last1=Jacobson |first1=RM |last2=St Sauver |first2=JL |last3=Griffin |first3=JM |last4=MacLaughlin |first4=KL |last5=Finney Rutten |first5=LJ |title=How health care providers should address vaccine hesitancy in the clinical setting: Evidence for presumptive language in making a strong recommendation |journal=Human Vaccines & Immunotherapeutics |date=April 2020 |volume=16 |issue=9 |pages=2131–2135 |doi=10.1080/21645515.2020.1735226 |pmid=32242766 |pmc=7553710 |doi-access=free}}</ref> Vaccination campaigns helped eradicate [[Medicine:Smallpox|smallpox]], which once killed as many as one in seven children in Europe,<ref name="Fenner">{{Cite book |url=http://whqlibdoc.who.int/smallpox/9241561106.pdf |title=Smallpox and its Eradication |vauthors=Fenner F, Henderson DA, Arita I, Ježek Z, Ladnyi ID |publisher=World Health Organization |year=1988 |isbn=978-92-4-156110-5 |location=Geneva |access-date=2007-09-04}}</ref> and have nearly [[Medicine:Poliomyelitis eradication|eradicated polio]].<ref>{{Cite book |chapter=Mass vaccination campaigns for polio eradication: an essential strategy for success |vauthors=Sutter RW, Maher C |title=Mass Vaccination: Global Aspects – Progress and Obstacles |work=Curr Top Microbiol Immunol |year=2006 |isbn=978-3-540-29382-8 |series=Current Topics in Microbiology and Immunology |volume=304 |pages=195–220 |doi=10.1007/3-540-36583-4_11 |pmid=16989271}}</ref> As a more modest example, infections caused by ''[[Biology:Haemophilus influenzae|Haemophilus influenzae]]'' (Hib), a major cause of bacterial meningitis and other serious diseases in children, have decreased by over 99% in the US since the introduction of a vaccine in 1988.<ref>{{Cite journal |last=Centers for Disease Control Prevention (CDC) |date=March 2002 |title=Progress toward elimination of Haemophilus influenzae type b invasive disease among infants and children – United States, 1998–2000 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5111a4.htm |journal=Morbidity and Mortality Weekly Report |volume=51 |issue=11 |pages=234–37 |pmid=11925021}}</ref> It is estimated that full vaccination, from birth to adolescence, of all US children born in a given year would save 33,000 lives and prevent 14 million infections.<ref>{{Cite news |url=http://www.time.com/time/health/article/0,8599,1808438-1,00.html |archive-url=https://web.archive.org/web/20080528022614/http://www.time.com/time/health/article/0,8599,1808438-1,00.html |url-status=dead |archive-date=May 28, 2008 |title=How safe are vaccines? |last=Park |first=Alice |date=June 2, 2008 |work=Time Magazine |url-access=subscription}}</ref>

There is anti-vaccine literature that argues that reductions in infectious disease result from improved sanitation and hygiene (rather than vaccination) or that these diseases were already in decline before the introduction of specific vaccines. These claims are not supported by scientific data; the incidence of vaccine-preventable diseases tended to fluctuate over time until the introduction of specific vaccines, at which point the incidence dropped to near zero. A Centers for Disease Control and Prevention website aimed at countering common misconceptions about vaccines argued, "Are we expected to believe that better sanitation caused the incidence of each disease to drop, just at the time a vaccine for that disease was introduced?"<ref name="CDC: common misconceptions">{{Cite web |url=https://www.cdc.gov/vaccines/vac-gen/6mishome.htm |title=Some common misconceptions about vaccination and how to respond to them |publisher=National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention |archive-url=https://web.archive.org/web/20150120055820/http://www.cdc.gov/vaccines/vac-gen/6mishome.htm |archive-date=January 20, 2015 |access-date=September 28, 2012}}</ref>

Another rallying cry of the anti-vaccine movement is to call for randomized clinical trials in which an experimental group of children are vaccinated while a control group are unvaccinated.  Such a study would never be approved because it would require deliberately denying children standard medical care, rendering the study unethical.  Studies have been done that compare vaccinated to unvaccinated people, but the studies are typically not randomized.  Moreover, literature already exists that demonstrates the safety of vaccines using other experimental methods.<ref>{{cite book |last1=Novella |first1=Steven |first2=Bob |last2=Novella |first3=Cara |last3=Santa Maria |first4=Jay |last4=Novella |first5=Evan |last5=Bernstein |title=The Skeptics' Guide to the Universe: How to Know What's Really Real in a World Increasingly Full of Fake |publisher=Grand Central Publishing |date=2018 |page=185 |isbn=9781538760512}}</ref>

Other critics argue that the immunity granted by vaccines is only temporary and requires boosters, whereas those who survive the disease become permanently immune.<ref name="wolfesharp" /> As discussed below, the philosophies of some alternative medicine practitioners are incompatible with the idea that vaccines are effective.<ref name="Ernst" />

===Population health===

[[File:Charlotte Cleverley-Bisman.jpg|thumb|Charlotte Cleverley-Bisman, is a child known as the face of a New Zealand campaign to encourage vaccination against meningococcal disease after contracting and surviving severe meningococcal sepsis.<ref>{{cite news |last =Johnston |first =Martin |date=3 July 2006 |url=http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10389468 |title=Vaccine campaign beating meningococcal epidemic |work=The New Zealand Herald |location=Auckland}}</ref> She had all four limbs partially amputated at age seven months due to meningococcal disease,<ref>{{Cite web |url=http://www.biocsl.co.nz/docs/957/642/NorthSouth_case-for-accination.pdf |title=The case for vaccination |last=Wane |first=Joanna |website=North & South |access-date=July 3, 2015}}</ref> which is preventable in children too young to vaccinate through widespread population vaccination sufficient to develop herd immunity.<ref name="pmid21427399">{{Cite journal |last1=Fine |first1=P. |last2=Eames |first2=K. |last3=Heymann |first3=D. L. |date=22 March 2011 |title='Herd Immunity': A Rough Guide |journal=Clinical Infectious Diseases |volume=52 |issue=7 |pages=911–16 |doi=10.1093/cid/cir007 |pmid=21427399|doi-access=free}}</ref>]]

Incomplete vaccine coverage increases the risk of disease for the entire population, including those who have been vaccinated, because it reduces [[Medicine:Herd immunity|herd immunity]]. For example, the measles vaccine is given to children 9–12 months old, and the window between the disappearance of maternal antibody and [[Biology:Seroconversion|seroconversion]] means that vaccinated children are frequently still vulnerable. Strong herd immunity reduces this vulnerability. Increasing herd immunity during an outbreak or when there is a risk of an outbreak is perhaps the most widely accepted justification for mass vaccination. When a new vaccine is introduced, mass vaccination can help increase coverage rapidly.<ref>{{Cite book |title=Mass Vaccination: Global Aspects – Progress and Obstacles |last1=Heymann |first1=D. L. |last2=Aylward |first2=R. B. |year=2006 |isbn=978-3-540-29382-8 |series=Current Topics in Microbiology and Immunology |volume=304 |pages=1–16 |chapter=Mass Vaccination: When and Why |doi=10.1007/3-540-36583-4_1 |pmid=16989261 |s2cid=25259803 }}</ref>

If enough of a population is vaccinated, herd immunity takes effect, decreasing risk to people who cannot receive vaccines because they are too young or old, immunocompromised, or have severe allergies to the ingredients in the vaccine.<ref>{{Cite journal |vauthors=Bester JC |date=September 2017 |title=Measles Vaccination is Best for Children: The Argument for Relying on Herd Immunity Fails |journal=Journal of Bioethical Inquiry |volume=14 |issue=3 |pages=375–84 |doi=10.1007/s11673-017-9799-4 |pmid=28815434 |s2cid=3177668}}</ref> The outcome for people with compromised immune systems who get infected is often worse than that of the general population.<ref>{{Cite web |url=https://www.cdc.gov/features/ReasonsToVaccinate |title=Immunization |date=2018-08-30 |publisher=CDC}}</ref>

===Cost-effectiveness===
Commonly used vaccines are a cost-effective and preventive way of promoting health, compared to the treatment of acute or chronic disease. In 2001, the United States spent approximately $2.8 billion to promote and implement routine childhood immunizations against seven diseases. The societal benefits of those vaccinations were estimated to be $46.6 billion, yielding a benefit-cost ratio of 16.5.<ref>{{Cite journal |vauthors=Zhou F, Santoli J, Messonnier ML, Yusuf HR, Shefer A, Chu SY, Rodewald L, Harpaz R |date=December 2005 |title=Economic evaluation of the 7-vaccine routine childhood immunization schedule in the United States, 2001 |journal=Archives of Pediatrics & Adolescent Medicine |volume=159 |issue=12 |pages=1136–44 |doi=10.1001/archpedi.159.12.1136 |pmid=16330737|doi-access=}}</ref>

===Necessity===
When a vaccination program successfully reduces the disease threat, it may reduce the perceived risk of disease as cultural memories of the effects of that disease fade. At this point, parents may feel they have nothing to lose by not vaccinating their children.<ref>{{Cite journal |vauthors=Fine PE, Clarkson JA |date=December 1986 |title=Individual versus public priorities in the determination of optimal vaccination policies |journal=American Journal of Epidemiology |volume=124 |issue=6 |pages=1012–20 |doi=10.1093/oxfordjournals.aje.a114471 |pmid=3096132}}</ref> If enough people hope to become free-riders, gaining the benefits of herd immunity without vaccination, vaccination levels may drop to a level where herd immunity is ineffective.<ref>{{Cite journal |vauthors=Buttenheim AM, Asch DA |date=December 2013 |title=Making vaccine refusal less of a free ride |journal=Human Vaccines & Immunotherapeutics |volume=9 |issue=12 |pages=2674–75 |doi=10.4161/hv.26676 |pmc=4162060 |pmid=24088616}}</ref> According to Jennifer Reich, those parents who believe vaccination to be quite effective but might prefer their children to remain unvaccinated, are those who are the most likely to be convinced to change their mind, as long as they are approached properly.<ref>{{Cite web |url=https://www.vox.com/first-person/2019/5/8/18535944/jessica-biel-measles-2019-outbreak-anti-vax |title=I've talked to dozens of parents about why they don't vaccinate. Here's what they told me. |last=Reich |first=Jennifer |date=June 13, 2019 |website=Vox |access-date=July 5, 2019}}</ref>

==Safety concerns==
While some anti-vaccinationists openly deny the improvements vaccination has made to public health or believe in conspiracy theories,<ref name="wolfesharp"/> it is much more common to cite concerns about safety.<ref name="LancetID">{{Cite journal |last=The Lancet Infectious Diseases |date=April 2007 |title=Tackling negative perceptions towards vaccination |journal=The Lancet Infectious Diseases |volume=7 |issue=4 |pages=235 |doi=10.1016/S1473-3099(07)70057-9 |pmid=17376373}}</ref> As with any medical treatment, there is a potential for vaccines to cause serious complications, such as severe allergic reactions,<ref>{{Cite web |url=https://www.cdc.gov/vaccines/vac-gen/side-effects.htm#mmr |title=Possible Side-effects from Vaccines |date=August 26, 2013 |publisher=Centers for Disease Control and Prevention |access-date=January 3, 2014}}</ref> but unlike most other medical interventions, vaccines are given to healthy people and so a higher standard of safety is demanded.<ref>{{Cite journal |last1=Chen |first1=Robert T. |last2=Hibbs |first2=Beth |date=July 1998 |title=Vaccine Safety: Current and Future Challenges |url=http://sites.utoronto.ca/virology/mby480/VaccineSafe/VaccineSafe.htm |journal=Pediatric Annals |volume=27 |issue=7 |pages=445–55 |doi=10.3928/0090-4481-19980701-11 |pmid=9677616 |access-date=January 3, 2014 |name-list-style=vanc}}</ref> While serious complications from vaccinations are possible, they are extremely rare and much less common than similar risks from the diseases they prevent.<ref name="CDC: common misconceptions" /> As the success of immunization programs increases and the incidence of disease decreases, public attention shifts away from the risks of disease to the risk of vaccination,<ref name="BH" /> and it becomes challenging for health authorities to preserve public support for vaccination programs.<ref>{{Cite journal |last=Mooney C |date=June 2009 |title=Why does the vaccine/autism controversy live on? |url=http://discovermagazine.com/2009/jun/06-why-does-vaccine-autism-controversy-live-on |journal=Discover}}</ref>

The overwhelming success of certain vaccinations has made certain diseases rare, and, consequently, has led to incorrect [[Philosophy:Heuristics in judgment and decision-making|heuristic thinking]] in weighing risks against benefits among people who are vaccine-hesitant.<ref name="Jacobson2015">{{Cite journal |last1=Jacobson |first1=RM |last2=St Sauver |first2=JL |last3=Finney Rutten |first3=LJ |date=November 2015 |title=Vaccine Hesitancy |journal=Mayo Clinic Proceedings |volume=90 |issue=11 |pages=1562–68 |doi=10.1016/j.mayocp.2015.09.006 |pmid=26541249|doi-access=free}}</ref> Once such diseases (e.g., ''Haemophilus influenzae B'') decrease in prevalence, people may no longer appreciate how serious the illness is due to a lack of familiarity with it and become complacent.<ref name="Jacobson2015" /> The lack of personal experience with these diseases reduces the perceived danger and thus reduces the perceived benefit of immunization.<ref name="Marshall2013" /> Conversely, certain illnesses (e.g., [[Medicine:Influenza|influenza]]) remain so common that vaccine-hesitant people mistakenly perceive the illness to be non-threatening despite clear evidence that the illness poses a significant threat to human health.<ref name="Jacobson2015" /> [[Omission bias|Omission]] and disconfirmation biases also contribute to vaccine hesitancy.<ref name="Jacobson2015" /><ref name="McClure2017" />

Various concerns about immunization have been raised. They have been addressed and the concerns are not supported by evidence.<ref name="Marshall2013">{{Cite journal |last=Marshall |first=GS |date=2013 |title=Roots of vaccine hesitancy |journal=S D Med |volume=Spec no |pages=52–57 |pmid=23444592}}</ref> Concerns about immunization safety often follow a pattern. First, some investigators suggest that a medical condition of increasing prevalence or unknown cause is an adverse effect of vaccination. The initial study and subsequent studies by the same group have an inadequate methodology, typically a poorly controlled or uncontrolled [[Medicine:Case series|case series]]. A premature announcement is made about the alleged adverse effect, resonating with individuals who have the condition, and underestimating the potential harm of forgoing vaccination to those whom the vaccine could protect. Other groups attempt to replicate the initial study but fail to get the same results. Finally, it takes several years to regain public confidence in the vaccine.<ref name="BH" /> Adverse effects ascribed to vaccines typically have an unknown origin, an increasing [[Medicine:Incidence (epidemiology)|incidence]], some [[Medicine:Biological plausibility|biological plausibility]], occurrences close to the time of vaccination, and dreaded outcomes.<ref>{{cite journal |vauthors=Leask J, Chapman S, Cooper Robbins SC |title='All manner of ills': The features of serious diseases attributed to vaccination |journal=Vaccine |year=2009 |volume=28 |issue=17 |pages=3066–3070 |pmid=19879997 |doi=10.1016/j.vaccine.2009.10.042}}</ref> In almost all cases, the public health effect is limited by cultural boundaries: English speakers worry about one vaccine causing [[Medicine:Autism|autism]], while French speakers worry about another vaccine causing multiple sclerosis, and Nigerians worry that a third vaccine causes infertility.<ref>{{Cite book |title=Bad Science |last=Goldacre |first=Ben |publisher=Fourth Estate |year=2009 |isbn=978-0007284870 |location=London |pages=292–94 |name-list-style=vanc}}</ref>

=== Thiomersal ===
{{Main|Unsolved:Thiomersal and vaccines}}

[[Chemistry:Thiomersal|Thiomersal]] (called "thimerosal" in the US) is an [[Chemistry:Antifungal|antifungal]] preservative used in small amounts in some multi-dose vaccines (where the same vial is opened and used for multiple patients) to prevent contamination of the vaccine.<ref name="Baker">{{Cite journal |vauthors=Baker JP |date=February 2008 |title=Mercury, vaccines, and autism: one controversy, three histories |journal=American Journal of Public Health |volume=98 |issue=2 |pages=244–53 |doi=10.2105/AJPH.2007.113159 |pmc=2376879 |pmid=18172138}}</ref> Despite thiomersal's efficacy, the use of thiomersal is controversial because it can be metabolized or degraded in the body to [[Chemistry:Ethylmercury|ethylmercury]] (C<sub>2</sub>H<sub>5</sub>Hg<sup>+</sup>) and thiosalicylate.<ref name=T-in-vaccines>{{cite web |date=June 3, 2008 |url=https://www.fda.gov/cber/vaccine/thimerosal.htm |archive-url=https://web.archive.org/web/20080726010009/https://www.fda.gov/cber/vaccine/thimerosal.htm |archive-date=July 26, 2008|url-status=dead |access-date=July 25, 2008 |title=Thimerosal in vaccines |publisher=Center for Biologics Evaluation and Research, U.S. Food and Drug Administration}}</ref><ref name=cber2019 /> As a result, in 1999, the Centers for Disease Control (CDC) and the American Academy of Pediatrics (AAP) asked vaccine makers to remove thiomersal from vaccines as quickly as possible on the [[Precautionary principle|precautionary principle]]. Thiomersal is now absent from all common US and European vaccines, except for some preparations of [[Medicine:Influenza vaccine|influenza vaccine]].<ref name="Offit">{{Cite journal |vauthors=Offit PA |date=September 2007 |title=Thimerosal and vaccines – a cautionary tale |journal=The New England Journal of Medicine |volume=357 |issue=13 |pages=1278–79 |doi=10.1056/NEJMp078187 |pmid=17898096 |s2cid=36318722|doi-access=free }}</ref> Trace amounts remain in some vaccines due to production processes, at an approximate maximum of one microgramme, around 15% of the average daily mercury intake in the US for adults and 2.5% of the daily level considered tolerable by the [[Organization:World Health Organization|WHO]].<ref name=cber2019>{{Cite journal |author=Center for Biologics Evaluation and Research |date=April 5, 2019 |title=Thimerosal and Vaccines |url=https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/thimerosal-and-vaccines |journal=FDA |publisher=fda.gov}}</ref><ref>{{Cite journal |vauthors=Bose-O'Reilly S, McCarty KM, Steckling N, Lettmeier B |date=September 2010 |title=Mercury exposure and children's health |journal=Current Problems in Pediatric and Adolescent Health Care |volume=40 |issue=8 |pages=186–215 |doi=10.1016/j.cppeds.2010.07.002 |pmc=3096006 |pmid=20816346}}</ref> The action sparked concern that thiomersal could have been responsible for autism.<ref name="Offit" /> The idea is now considered disproven, as incidence rates for autism increased steadily even after thiomersal was removed from childhood vaccines.<ref name="Gerber" /> Currently there is no accepted scientific evidence that exposure to thiomersal is a factor in causing autism.<ref>{{Cite journal |vauthors=Doja A, Roberts W |date=November 2006 |title=Immunizations and autism: a review of the literature |journal=The Canadian Journal of Neurological Sciences |volume=33 |issue=4 |pages=341–46 |doi=10.1017/s031716710000528x |pmid=17168158|doi-access=free}}</ref><ref name="Spencer2017">{{Cite journal |last1=Spencer |first1=JP |last2=Trondsen Pawlowski |first2=RH |last3=Thomas |first3=S |date=June 2017 |title=Vaccine Adverse Events: Separating Myth from Reality. |url=https://www.aafp.org/afp/2017/0615/p786.html |journal=American Family Physician |volume=95 |issue=12 |pages=786–94 |pmid=28671426}}</ref> Since 2000, parents in the United States have pursued legal compensation from a federal fund arguing that thiomersal caused autism in their children.<ref name="Sugarman">{{Cite journal |vauthors=Sugarman SD |date=September 2007 |title=Cases in vaccine court – legal battles over vaccines and autism |journal=The New England Journal of Medicine |volume=357 |issue=13 |pages=1275–77 |doi=10.1056/NEJMp078168 |pmid=17898095 |doi-access=free }}</ref> A 2004 Institute of Medicine (IOM) committee favored rejecting any causal relationship between thiomersal-containing vaccines and autism.<ref name="ISRC">{{Cite book |url=http://www.nap.edu/catalog.php?record_id=10997 |title=Immunization Safety Review: Vaccines and Autism |last=Immunization Safety Review Committee |publisher=The National Academies Press |year=2004 |isbn=978-0-309-09237-1 |doi=10.17226/10997 |pmid=20669467}}</ref> The concentration of thiomersal used in vaccines as an antimicrobial agent ranges from 0.001% (1 part in 100,000) to 0.01% (1 part in 10,000).<ref name="FDAThiomersalTuna" /> A vaccine containing 0.01% thiomersal has 25 micrograms of mercury per 0.5 mL dose, roughly the same amount of elemental mercury found in a {{convert|3|oz|g|adj=on|spell=in}} can of [[Biology:Tuna|tuna]].<ref name="FDAThiomersalTuna">{{Cite web |url=https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/thimerosal-and-vaccines#pres |title=Thimerosal and Vaccines |date=April 5, 2019 |website=fda.gov |publisher=U.S. Food and Drug Administration}}</ref> There is robust peer-reviewed scientific evidence supporting the safety of thiomersal-containing vaccines.<ref name="FDAThiomersalTuna" />

=== MMR vaccine ===
{{Main|Social:MMR vaccine and autism}}

In the UK, the [[Medicine:MMR vaccine|MMR vaccine]] was the subject of controversy after the publication in ''The Lancet'' of a 1998 paper by [[Biography:Andrew Wakefield|Andrew Wakefield]] and others reporting case histories of twelve children mostly with [[Medicine:Autism spectrum|autism spectrum disorders]] with onset soon after administration of the vaccine.<ref>{{Cite journal |vauthors=Wakefield AJ, Murch SH, Anthony A, Linnell J, Casson DM, Malik M, Berelowitz M, Dhillon AP, Thomson MA, Harvey P, Valentine A, Davies SE, Walker-Smith JA |date=February 1998 |title=Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children |journal=Lancet |volume=351 |issue=9103 |pages=637–41 |doi=10.1016/S0140-6736(97)11096-0 |pmid=9500320 |s2cid=439791 |author-link1=Andrew Wakefield}}{{Retracted paper |intentional=yes}}</ref> At a 1998 press conference, Wakefield suggested that giving children the vaccines in three separate doses would be safer than a single vaccination. This suggestion was not supported by the paper, and several subsequent peer-reviewed studies have failed to show any association between the vaccine and autism.<ref name="NHS">{{Cite web |url=https://www.nhs.uk/conditions/vaccinations/mmr-vaccine/ |title=MMR vaccine |last=National Health Service |year=2015 |access-date=4 July 2018}}</ref> It later emerged that Wakefield had received funding from litigants against vaccine manufacturers and that he had not informed colleagues or medical authorities of his [[Philosophy:Conflict of interest|conflict of interest]]: Wakefield reportedly stood to earn up to $43 million per year selling diagnostic kits.<ref name="WakefieldCapitalize">{{cite news|last=Stein|first=Rob|date=11 January 2011|title=Wakefield tried to capitalize on autism-vaccine link, report says|newspaper={{wipe|The Washington Post}}|url=http://voices.washingtonpost.com/checkup/2011/01/wakefield_tried_to_capitalize.html|access-date=12 January 2011|archive-url=https://web.archive.org/web/20120630205839/http://voices.washingtonpost.com/checkup/2011/01/wakefield_tried_to_capitalize.html|archive-date=2012-06-30 |url-status=live }}</ref><ref>{{Cite news |url=http://www.timesonline.co.uk/tol/news/uk/health/article1027603.ece |title=Revealed: MMR research scandal |last=Deer |first=Brian |date=2004-02-22 |work=The Sunday Times |access-date=2007-09-23}}</ref> Had this been known, publication in ''The Lancet'' would not have taken place in the way that it did.<ref>{{Cite journal |vauthors=Horton R |date=March 2004 |title=The lessons of MMR |journal=Lancet |volume=363 |issue=9411 |pages=747–49 |doi=10.1016/S0140-6736(04)15714-0 |pmid=15016482 |s2cid=5357597}}</ref> Wakefield has been heavily criticized on scientific and ethical grounds for the way the research was conducted<ref name="paid_children">{{Cite news |url=http://news.bbc.co.uk/2/hi/health/6289166.stm |title=MMR scare doctor 'paid children' |date=2007-07-16 |work=BBC News}}</ref> and for triggering a decline in vaccination rates, which fell in the UK to 80% in the years following the study.<ref>{{Cite news |url=http://news.bbc.co.uk/2/hi/health/5118166.stm |title=Doctors issue plea over MMR jab |date=2006-06-26 |work=BBC News |access-date=2007-11-23}}</ref><ref name=Alazraki11/> In 2004, the MMR-and-autism interpretation of the paper was formally retracted by ten of its thirteen coauthors,<ref>{{Cite journal |vauthors=Murch SH, Anthony A, Casson DH, Malik M, Berelowitz M, Dhillon AP, Thomson MA, Valentine A, Davies SE, Walker-Smith JA |date=March 2004 |title=Retraction of an interpretation |journal=Lancet |volume=363 |issue=9411 |pages=750 |doi=10.1016/S0140-6736(04)15715-2 |pmid=15016483 |s2cid=5128036}}</ref> and in 2010 ''The Lancet''{{'}}s editors fully retracted the paper.<ref>{{Cite journal |author=((The Editors Of The Lancet)) |date=February 2010 |title=Retraction – Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children |url=https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(10)60175-4/fulltext |journal=The Lancet |volume=375 |issue=9713 |pages=445 |doi=10.1016/S0140-6736(10)60175-4 |pmid=20137807 |s2cid=26364726}}</ref><ref name="Triggle_2/2/2010">{{cite web | last=Triggle | first=Nick | title=Lancet accepts MMR study 'false' | website=BBC News | date=February 2, 2010 | url=http://news.bbc.co.uk/2/low/health/8493753.stm | access-date=February 28, 2022}}</ref> Wakefield was struck off the UK medical register, with a statement identifying deliberate falsification in the research published in ''The Lancet'',<ref name="gmc-uk_Wakefield_SPM">{{Cite web |url=http://www.gmc-uk.org/Wakefield_SPM_and_SANCTION.pdf_32595267.pdf |title=General Medical Council, Fitness to Practise Panel Hearing, 24 May 2010, Andrew Wakefield, Determination of Serious Professional Misconduct |publisher=General Medical Council |url-status=dead |archive-url=https://web.archive.org/web/20130512115524/http://www.gmc-uk.org/Wakefield_SPM_and_SANCTION.pdf_32595267.pdf |archive-date=May 12, 2013 |access-date=September 18, 2011}}</ref> and is barred from practicing medicine in the UK.<ref name="MeikleBoseley">{{Cite news |url=https://www.theguardian.com/society/2010/may/24/mmr-doctor-andrew-wakefield-struck-off |title=MMR row doctor Andrew Wakefield struck off register |last1=Meikle |first1=James |date=May 24, 2010 |work=The Guardian |access-date=May 24, 2010 |url-status=live |archive-url=https://web.archive.org/web/20100527003931/http://www.guardian.co.uk/society/2010/may/24/mmr-doctor-andrew-wakefield-struck-off |archive-date=May 27, 2010 |last2=Boseley |first2=Sarah |location=London}}</ref>

The CDC, the IOM of the National Academy of Sciences, Australia's Department of Health, and the UK National Health Service have all concluded that there is no evidence of a link between the MMR vaccine and autism.<ref name="ISRC" /><ref>{{Cite web |url=http://cdc.gov/vaccinesafety/Concerns/Autism/Index.html |title=Concerns about autism |date=2010-01-15 |publisher=Centers for Disease Control and Prevention}}</ref><ref>{{Cite web |url=http://www.mmrthefacts.nhs.uk/ |title=MMR The facts |publisher=United Kingdom National Health Service |url-status=dead |archive-url=https://web.archive.org/web/20070615000359/http://www.mmrthefacts.nhs.uk/ |archive-date=June 15, 2007 |access-date=June 13, 2007}}</ref><ref name="AustraliaVaccines">{{cite web |title=Are Vaccines Safe? |url=https://www.health.gov.au/health-topics/immunisation/about-immunisation/are-vaccines-safe#no-established-link-between-vaccines-and-autism |website=health.gov.au |date=October 24, 2017 |publisher=Australia Department of Health}}</ref> A Cochrane review concluded that there is no credible link between the MMR vaccine and autism, that MMR has prevented diseases that still carry a heavy burden of death and complications, that the lack of confidence in MMR has damaged public health, and that the design and reporting of safety outcomes in MMR vaccine studies are largely inadequate.<ref name="pmid22336803">{{Cite journal |vauthors=Demicheli V, Rivetti A, Debalini MG, Di Pietrantonj C |date=February 2012 |editor-last=Demicheli |editor-first=Vittorio |title=Vaccines for measles, mumps and rubella in children |journal=The Cochrane Database of Systematic Reviews |volume=2 |issue=2 |pages=CD004407 |doi=10.1002/14651858.CD004407.pub3 |pmc=6458016 |pmid=22336803}}</ref> Additional reviews agree, with studies finding that vaccines are not linked to autism even in high risk populations with autistic siblings.<ref>{{Cite journal |last1=DeStefano |first1=Frank |last2=Shimabukuro |first2=Tom T. |date=2019-04-15 |title=The MMR Vaccine and Autism |journal=Annual Review of Virology |volume=6 |issue=1 |pages=585–600 |doi=10.1146/annurev-virology-092818-015515 |issn=2327-0578 |pmc=6768751 |pmid=30986133}}</ref>

In 2009, ''The Sunday Times'' reported that Wakefield had manipulated patient data and misreported results in his 1998 paper, creating the appearance of a link with autism.<ref>{{Cite news |url=http://www.timesonline.co.uk/tol/life_and_style/health/article5683671.ece |title=MMR doctor Andrew Wakefield fixed data on autism |last=Deer B |date=2009-02-08 |work=Sunday Times |access-date=2009-02-09}}</ref> A 2011 article in the ''British Medical Journal'' described how the data in the study had been falsified by Wakefield so that it would arrive at a predetermined conclusion.<ref>{{Cite journal |vauthors=Deer B |date=January 2011 |title=How the case against the MMR vaccine was fixed |journal=BMJ |volume=342 |pages=c5347 |doi=10.1136/bmj.c5347 |pmid=21209059|doi-access=|s2cid=46683674 }}</ref> An accompanying editorial in the same journal described Wakefield's work as an "elaborate [[Finance:Fraud|fraud]]" that led to lower vaccination rates, putting hundreds of thousands of children at risk and diverting energy and money away from research into the true cause of autism.<ref>{{Cite journal |vauthors=Godlee F, Smith J, Marcovitch H |date=January 2011 |title=Wakefield's article linking MMR vaccine and autism was fraudulent |journal=BMJ |volume=342 |pages=c7452 |doi=10.1136/bmj.c7452 |pmid=21209060 |s2cid=43640126}}</ref>

A special court convened in the United States to review claims under the [[Medicine:Vaccine court|National Vaccine Injury Compensation Program]] ruled on February 12, 2009, that the evidence "failed to demonstrate that thimerosal-containing vaccines can contribute to causing immune dysfunction, or that the MMR vaccine can contribute to causing either autism or gastrointestinal dysfunction", and that parents of autistic children were therefore not entitled to compensation in their contention that certain vaccines caused autism in their children.<ref>Vaccine court and autism:
*{{cite news |url=http://www.cnn.com/2009/HEALTH/02/12/autism.vaccines/index.html |first=Miriam |last=Falco |title=Vaccine didn't cause autism, court rules |date=2009-02-12 |publisher=CNN |access-date=2009-02-12}}
*{{cite court |litigants=Theresa Cedillo and Michael Cedillo, as parents and natural guardians of Michelle Cedillo vs. Secretary of Health and Human Services |vol=98-916V |court=United States Court of Federal Claims |date=2009-02-12 |url=https://www.uscfc.uscourts.gov/sites/default/files/vaccine_files/Hastings-Cedillo.pdf}}</ref>

===Vaccine overload===
''Vaccine overload'', a non-medical term, is the notion that giving many vaccines at once may overwhelm or weaken a child's immature immune system and lead to adverse effects.<ref name="Hilton" /> Despite scientific evidence that strongly contradicts this idea,<ref name="Gerber" /> there are still parents of autistic children that believe that vaccine overload causes autism.<ref>{{Cite news |url=https://www.thestar.com/news/article/718829 |title=Vaccine phobia runs deep |last=Hurst L |date=2009-10-30 |work=Toronto Star |access-date=2009-11-04}}</ref> The resulting controversy has caused many parents to delay or avoid immunizing their children.<ref name="Hilton">{{Cite journal |vauthors=Hilton S, Petticrew M, Hunt K |date=May 2006 |title='Combined vaccines are like a sudden onslaught to the body's immune system': parental concerns about vaccine 'overload' and 'immune-vulnerability' |journal=Vaccine |volume=24 |issue=20 |pages=4321–27 |doi=10.1016/j.vaccine.2006.03.003 |pmid=16581162}}</ref> Such parental misperceptions are major obstacles towards immunization of children.<ref>{{Cite journal |vauthors=Heininger U |date=September 2006 |title=An internet-based survey on parental attitudes towards immunization |journal=Vaccine |volume=24 |issue=37–39 |pages=6351–55 |doi=10.1016/j.vaccine.2006.05.029 |pmid=16784799}}</ref>

The concept of vaccine overload is flawed on several levels.<ref name="Gerber" /> Despite the increase in the number of vaccines over recent decades, improvements in vaccine design have reduced the immunologic load from vaccines; the total number of immunological components in the 14 vaccines administered to US children in 2009 is less than ten percent of what it was in the seven vaccines given in 1980.<ref name="Gerber">{{Cite journal |vauthors=Gerber JS, Offit PA |date=February 2009 |title=Vaccines and autism: a tale of shifting hypotheses |journal=Clinical Infectious Diseases |volume=48 |issue=4 |pages=456–61 |doi=10.1086/596476 |pmc=2908388 |pmid=19128068 }}</ref> A study published in 2013 found no correlation between autism and the [[Biology:Antigen|antigen]] number in the vaccines the children were administered up to the age of two. There were 1,008 children in the study, one quarter of whom were diagnosed with autism, and the whole cohort was born between 1994 and 1999, when the routine vaccine schedule could contain more than 3,000 antigens (in a single shot of [[Medicine:DTP vaccine|DTP vaccine]]). The vaccine schedule in 2012 contains several more vaccines, but the number of antigens the child is exposed to by the age of two is 315.<ref>{{Cite web |url=https://www.forbes.com/sites/emilywillingham/2013/03/29/vaccines-not-linked-to-autism-again/ |title=Vaccines Not Linked To Autism. Again |last=Willingham, Emily |author-link=Emily Willingham |date=March 29, 2013 |website=Forbes |access-date=April 4, 2013}}</ref><ref>{{Cite journal |author-link=Frank DeStefano |vauthors=DeStefano F, Price CS, Weintraub ES |date=August 2013 |title=Increasing exposure to antibody-stimulating proteins and polysaccharides in vaccines is not associated with risk of autism |url=http://www.jpeds.com/webfiles/images/journals/ympd/JPEDSDeStefano.pdf |journal=The Journal of Pediatrics |volume=163 |issue=2 |pages=561–77 |citeseerx=10.1.1.371.2592 |doi=10.1016/j.jpeds.2013.02.001 |pmid=23545349 |access-date=April 4, 2013 |archive-date=September 23, 2014 |archive-url=https://web.archive.org/web/20140923222908/http://www.jpeds.com/webfiles/images/journals/ympd/JPEDSDeStefano.pdf |url-status=dead }}</ref> Vaccines pose a very small immunologic load compared to the pathogens naturally encountered by a child in a typical year;<ref name="Gerber" /> common childhood conditions such as fevers and [[Medicine:Otitis media|middle-ear infections]] pose a much greater challenge to the immune system than vaccines,<ref>Immune challenges:
*{{cite journal |vauthors=Murphy TF |title=Branhamella catarrhalis: epidemiology, surface antigenic structure, and immune response |journal=Microbiological Reviews |volume=60 |issue=2 |pages=267–79 |date=June 1996 |doi=10.1128/MMBR.60.2.267-279.1996 |pmid=8801433 |pmc=239443 |url=}}
*{{cite journal |vauthors=Sloyer JL, Howie VM, Ploussard JH, Ammann AJ, Austrian R, Johnston RB |title=Immune response to acute otitis media in children. I. Serotypes isolated and serum and middle ear fluid antibody in pneumococcal otitis media |journal=Infection and Immunity |volume=9 |issue=6 |pages=1028–32 |date=June 1974 |doi=10.1128/IAI.9.6.1028-1032.1974 |pmid=4151506 |pmc=414928 |url=}}</ref> and studies have shown that vaccinations, even multiple concurrent vaccinations, do not weaken the immune system<ref name="Gerber" /> or compromise overall immunity.<ref>Vaccine burden:
*{{cite journal |vauthors=Miller E, Andrews N, Waight P, Taylor B |title=Bacterial infections, immune overload, and MMR vaccine. Measles, mumps, and rubella |journal=Archives of Disease in Childhood |volume=88 |issue=3 |pages=222–23 |date=March 2003 |pmid=12598383 |pmc=1719482 |doi=10.1136/adc.88.3.222}}
*{{cite journal |vauthors=Hviid A, Wohlfahrt J, Stellfeld M, Melbye M |title=Childhood vaccination and nontargeted infectious disease hospitalization |journal=JAMA |volume=294 |issue=6 |pages=699–705 |date=August 2005 |pmid=16091572 |doi=10.1001/jama.294.6.699 | doi-access = }}</ref> The lack of evidence supporting the vaccine overload hypothesis, combined with these findings directly contradicting it, has led to the conclusion that currently recommended vaccine programs do not "overload" or weaken the immune system.<ref name="BH" /><ref>{{Cite journal |vauthors=Gregson AL, Edelman R |date=November 2003 |title=Does antigenic overload exist? The role of multiple immunizations in infants |journal=Immunology and Allergy Clinics of North America |volume=23 |issue=4 |pages=649–64 |doi=10.1016/S0889-8561(03)00097-3 |pmid=14753385}}</ref><ref name="Hackett-Offit" /><ref name="Schneeweiss" />

Any experiment based on withholding vaccines from children is considered unethical,<ref>{{Cite journal |vauthors=Deen JL, Clemens JD |date=November 2006 |title=Issues in the design and implementation of vaccine trials in less developed countries |journal=Nature Reviews. Drug Discovery |volume=5 |issue=11 |pages=932–40 |doi=10.1038/nrd2159 |pmid=17080029 |s2cid=413230|doi-access=free }}</ref> and observational studies would likely be [[Confounding|confounded]] by differences in the healthcare-seeking behaviors of under-vaccinated children. Thus, no study directly comparing rates of autism in vaccinated and unvaccinated children has been done. However, the concept of vaccine overload is biologically implausible, as vaccinated and unvaccinated children have the same immune response to non-vaccine-related infections, and autism is not an immune-mediated disease, so claims that vaccines could cause it by overloading the immune system go against current knowledge of the [[Medicine:Pathogenesis|pathogenesis]] of autism. As such, the idea that vaccines cause autism has been effectively dismissed by the weight of current evidence.<ref name="Gerber" />

===Prenatal infection===
There is evidence that [[Medicine:Schizophrenia|schizophrenia]] is associated with prenatal exposure to [[Medicine:Rubella|rubella]], [[Medicine:Influenza|influenza]], and [[Medicine:Toxoplasmosis|toxoplasmosis]] infection. For example, one study found a sevenfold increased risk of schizophrenia when mothers were exposed to influenza in the first trimester of gestation. This may have public health implications, as strategies for preventing infection include vaccination, simple hygiene, and, in the case of toxoplasmosis, [[Chemistry:Antibiotic|antibiotic]]s.<ref>{{Cite journal |vauthors=Fineberg AM, Ellman LM |date=May 2013 |title=Inflammatory cytokines and neurological and neurocognitive alterations in the course of schizophrenia |journal=Biological Psychiatry |volume=73 |issue=10 |pages=951–66 |doi=10.1016/j.biopsych.2013.01.001 |pmc=3641168 |pmid=23414821}}</ref> Based on studies in animal models, theoretical concerns have been raised about a possible link between schizophrenia and maternal immune response activated by virus antigens; a 2009 review concluded that there was insufficient evidence to recommend routine use of [[Medicine:Influenza vaccine|trivalent influenza vaccine]] during the first trimester of pregnancy, but that the vaccine was still recommended outside the first trimester and in special circumstances such as pandemics or in women with certain other conditions.<ref>{{Cite journal |vauthors=Skowronski DM, De Serres G |date=July 2009 |title=Is routine influenza immunization warranted in early pregnancy? |journal=Vaccine |volume=27 |issue=35 |pages=4754–70 |doi=10.1016/j.vaccine.2009.03.079 |pmid=19515466}}</ref> The CDC's Advisory Committee on Immunization Practices, the American College of Obstetricians and Gynecologists, and the American Academy of Family Physicians all recommend routine flu shots for pregnant women, for several reasons:<ref name="ACIP2007" />
*their risk for serious influenza-related medical complications during the last two trimesters;
*their greater rates for flu-related hospitalizations compared to non-pregnant women;
*the possible transfer of maternal anti-influenza antibodies to children, protecting the children from the flu; and
*several studies that found no harm to pregnant women or their children from the vaccinations.

Despite this recommendation, only 16% of healthy pregnant US women surveyed in 2005 had been vaccinated against the flu.<ref name="ACIP2007">{{Cite journal |vauthors=Fiore AE, Shay DK, Haber P, Iskander JK, Uyeki TM, Mootrey G, Bresee JS, Cox NJ |date=July 2007 |title=Prevention and control of influenza. Recommendations of the Advisory Committee on Immunization Practices (ACIP), 2007 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5606a1.htm |journal=MMWR. Recommendations and Reports |volume=56 |issue=RR-6 |pages=1–54 |pmid=17625497}}</ref>

===Ingredient concerns===
Aluminum compounds are used as [[Biology:Immunologic adjuvant|immunologic adjuvant]]s to increase the effectiveness of many vaccines.<ref name="Principi2018">{{Cite journal |last1=Principi |first1=N |last2=Esposito |first2=S |date=September 2018 |title=Aluminum in vaccines: Does it create a safety problem? |journal=Vaccine |volume=36 |issue=39 |pages=5825–31 |doi=10.1016/j.vaccine.2018.08.036 |pmid=30139653|s2cid=52073320 }}</ref> The aluminum in vaccines simulates or causes small amounts of tissue damage, driving the body to respond more powerfully to what it sees as a serious infection and promoting the development of a lasting immune response.<ref name="Baylor" /><ref>{{Cite journal |vauthors=Leslie M |date=July 2013 |title=Solution to vaccine mystery starts to crystallize |journal=Science |volume=341 |issue=6141 |pages=26–27 |bibcode=2013Sci...341...26L |doi=10.1126/science.341.6141.26 |pmid=23828925}}</ref> In some cases these compounds have been associated with redness, itching, and low-grade fever,<ref name="Baylor">{{Cite journal |vauthors=Baylor NW, Egan W, Richman P |date=May 2002 |title=Aluminum salts in vaccines – US perspective |journal=Vaccine |volume=20 |issue=Suppl 3 |pages=S18–23 |doi=10.1016/S0264-410X(02)00166-4 |pmid=12184360}}</ref> but the use of aluminum in vaccines has not been associated with serious adverse events.<ref name="Principi2018" /><ref name="Francois" /> In some cases, aluminum-containing vaccines are associated with [[Unsolved:Macrophagic myofasciitis|macrophagic myofasciitis]] (MMF), localized microscopic [[Medicine:Lesion|lesion]]s containing aluminum salts that persist for up to 8 years. However, recent case-controlled studies have found no specific clinical symptoms in individuals with biopsies showing MMF, and there is no evidence that aluminum-containing vaccines are a serious health risk or justify changes to immunization practice.<ref name="Principi2018" /><ref name="Francois">{{Cite journal |display-authors=3 |vauthors=François G, Duclos P, Margolis H, Lavanchy D, Siegrist CA, Meheus A, Lambert PH, Emiroğlu N, Badur S, Van Damme P |date=November 2005 |title=Vaccine safety controversies and the future of vaccination programs |journal=The Pediatric Infectious Disease Journal |volume=24 |issue=11 |pages=953–61 |doi=10.1097/01.inf.0000183853.16113.a6 |pmid=16282928 |s2cid=10484014}}</ref> Infants are exposed to greater quantities of aluminum in daily life in breastmilk and infant formula than in vaccines.<ref name="Smith2015" /> In general, people are exposed to low levels of naturally occurring aluminum in nearly all foods and drinking water.<ref name="OxfordVaccineIngredients">{{Cite web |url=http://vk.ovg.ox.ac.uk/vaccine-ingredients#aluminium |title=Vaccine Ingredients |website=Vaccine Knowledge Project |publisher=Centre for Clinical Vaccinology and Tropical Medicine, Churchill Hospital, University of Oxford}}</ref> The amount of aluminum present in vaccines is small, less than one milligram, and such low levels are not believed to be harmful to human health.<ref name="OxfordVaccineIngredients" />

Vaccine hesitant people have also voiced strong concerns about the presence of [[Physics:Formaldehyde|formaldehyde]] in vaccines. Formaldehyde is used in very small concentrations to inactivate viruses and bacterial toxins used in vaccines.<ref name="FDAVaccineIngredient" /> Very small amounts of residual formaldehyde can be present in vaccines but are far below values harmful to human health.<ref name="CHOPformaldehyde">{{Cite web |url=https://www.chop.edu/centers-programs/vaccine-education-center/vaccine-ingredients/formaldehyde |title=Vaccine Ingredients-Formaldehyde |date=November 6, 2014 |website=chop.edu/ |publisher=Children's Hospital of Philadelphia}}</ref><ref name="Vaccineingredients">{{Cite web |url=https://www.vaccines.gov/basics/vaccine_ingredients |title=Vaccine Ingredients |website=vaccines.gov/ |date=April 26, 2021 |publisher=U.S. Department of Health and Human Services}}</ref> The levels present in vaccines are minuscule when compared to naturally occurring levels of formaldehyde in the human body and pose no significant risk of toxicity.<ref name="FDAVaccineIngredient">{{Cite web |url=https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/common-ingredients-us-licensed-vaccines |title=Common Ingredients Used in U.S. Licensed Vaccines |date=April 19, 2019 |website=fda.gov |publisher=U.S. Food and Drug Administration}}</ref> The human body continuously produces formaldehyde naturally and contains 50–70 times the greatest amount of formaldehyde present in any vaccine.<ref name="FDAVaccineIngredient" /> Furthermore, the human body is capable of breaking down naturally occurring formaldehyde as well as the small amount of formaldehyde present in vaccines.<ref name="FDAVaccineIngredient" /> There is no evidence linking the infrequent exposures to small quantities of formaldehyde present in vaccines with [[Medicine:Cancer|cancer]].<ref name="FDAVaccineIngredient" />

===Sudden infant death syndrome===
[[Medicine:Sudden infant death syndrome|Sudden infant death syndrome]] (SIDS) is most common in infants around the time in life when they receive many vaccinations.<ref name="PediatricsSIDS2016">{{cite journal |last1=Moon |first1=RY |last2=Task Force on Sudden Infant Death Syndrome |title=SIDS and Other Sleep-Related Infant Deaths: Evidence Base for 2016 Updated Recommendations for a Safe Infant Sleeping Environment. |journal=Pediatrics |date=November 2016 |volume=138 |issue=5 |pages=e20162940 |doi=10.1542/peds.2016-2940 |pmid=27940805 |url=https://pediatrics.aappublications.org/content/138/5/e20162940.long|doi-access=free}}</ref> Since the cause of SIDS has not been fully determined, this led to concerns about whether vaccines, in particular diphtheria-tetanus toxoid vaccines, were a possible causal factor.<ref name="PediatricsSIDS2016"/> Several studies investigated this and found no evidence supporting a causal link between vaccination and SIDS.<ref name="PediatricsSIDS2016"/><ref name="2016TaskForceSIDSRecs">{{cite journal |last1=Task Force on Sudden Infant Death Syndrome |title=SIDS and Other Sleep-Related Infant Deaths: Updated 2016 Recommendations for a Safe Infant Sleeping Environment. |journal=Pediatrics |date=November 2016 |volume=138 |issue=5 |pages=e20162938 |doi=10.1542/peds.2016-2938 |pmid=27940804 |url=https://pediatrics.aappublications.org/content/138/5/e20162938.long |access-date=13 December 2019|doi-access=free}}</ref> In 2003, the Institute of Medicine favored rejection of a causal link to [[Medicine:DTP vaccine|DTwP]] vaccination and SIDS after reviewing the available evidence.<ref>{{cite book |last1=Institute of Medicine (US) Immunization Safety Review Committee |last2=Stratton |first2=K |last3=Almario |first3=DA |last4=Wizemann |first4=TM |last5=McCormick |first5=MC |title=Immunization Safety Review: Vaccinations and Sudden Unexpected Death in Infancy |date=2003 |publisher=National Academies Press (US) |location=Washington D.C. |pmid=25057654 |url=https://www.ncbi.nlm.nih.gov/books/NBK221466/pdf/Bookshelf_NBK221466.pdf|access-date=13 December 2019}}</ref> Additional analyses of VAERS data also showed no relationship between vaccination and SIDS.<ref name="PediatricsSIDS2016"/> Studies have shown a negative correlation between SIDs and vaccination. That is vaccinated children are less likely to die but no causal link has been found. One suggestion is that infants who are less likely to develop SIDS are more likely to be presented for vaccination.<ref name="PediatricsSIDS2016"/><ref name="2016TaskForceSIDSRecs"/><ref name="Vennemann2007">{{cite journal |last1=Vennemann |first1=MM |last2=Höffgen |first2=M |last3=Bajanowski |first3=T |last4=Hense |first4=HW |last5=Mitchell |first5=EA |title=Do immunisations reduce the risk for SIDS? A meta-analysis. |journal=Vaccine |date=June 2007 |volume=25 |issue=26 |pages=4875–79 |doi=10.1016/j.vaccine.2007.02.077 |pmid=17400342}}</ref>

===Anthrax vaccines===
In the mid-1990s media reports on vaccines discussed the Gulf War Syndrome, a multi-symptomatic disorder affecting returning US military veterans of the 1990–1991 Persian Gulf War. Among the first articles of the online magazine ''Slate'' was one by Atul Gawande in which the required immunizations received by soldiers, including an [[Social:Anthrax vaccines|anthrax vaccination]], were named as one of the likely culprits for the symptoms associated with the Gulf War Syndrome. In the late 1990s ''Slate'' published an article on the "brewing rebellion" in the military against anthrax immunization because of "the availability to soldiers of vaccine misinformation on the Internet". ''Slate'' continued to report on concerns about the required anthrax and [[Medicine:Smallpox|smallpox]] immunization for US troops after the September&nbsp;11 attacks and articles on the subject also appeared on the ''Salon'' website.<ref name="hausman">{{Cite book |title=Anti/Vax: Reframing the Vaccination Controversy |last1=Hausman |first1=Bernice L. |publisher=Cornell University Press |year=2019 |isbn=9781501735639 |pages=28, 39–42}}</ref> The 2001 anthrax attacks heightened concerns about [[Social:Bioterrorism|bioterrorism]] and the Federal government of the United States stepped up its efforts to store and create more vaccines for American citizens.<ref name=hausman/> In 2002, ''Mother Jones'' published an article that was highly skeptical of the anthrax and smallpox immunization required by the United States Armed Forces.<ref name=hausman/> With the 2003 invasion of Iraq a wider controversy ensued in the media about requiring US troops to be vaccinated against anthrax.<ref name=hausman/> From 2003 to 2008 a series of court cases were brought to oppose the compulsory anthrax vaccination of US troops.<ref name=hausman/>

===Swine flu vaccine===
[[File:President Ford receives a swine flu inoculation - NARA - 7064718.jpg|thumb|upright=1.3|U.S. President Gerald Ford receiving his vaccine for the swine flu.]]

The US [[Medicine:Swine influenza|swine flu]] immunization campaign in response to the [[Biology:1976 swine flu outbreak|1976 swine flu outbreak]] has become known as "the swine flu fiasco" because the outbreak did not lead to a [[Finance:Pandemic|pandemic]] as US President Gerald Ford had feared and the hastily rolled out vaccine was found to increase the number of Guillain–Barré Syndrome cases two weeks after immunization. Government officials stopped the mass immunization campaign due to great anxiety about the safety of the swine flu vaccine. The general public was left with greater fear of the [[Biology:Vaccination|vaccination campaign]] than the virus itself, and vaccination policies, in general, were challenged.<ref>{{cite book |first=Archana |last=Chatterjee |title=Vaccinophobia and Vaccine Controversies of the 21st Century |publisher=Springer Science & Business Media |year=2013 |pages=8 |isbn=9781461474388}}</ref>

During the 2009 flu pandemic, significant controversy broke out regarding whether the [[Medicine:2009 flu pandemic vaccine|2009 H1N1 flu vaccine]] was safe in, among other countries, {{wipe|France}}. Numerous different French groups publicly criticized the vaccine as potentially dangerous.<ref>{{Cite journal |vauthors=Ward JK |date=June 2016 |title=Rethinking the antivaccine movement concept: A case study of public criticism of the swine flu vaccine's safety in France |journal=Social Science & Medicine |volume=159 |pages=48–57 |doi=10.1016/j.socscimed.2016.05.003 |pmid=27173740}}</ref> Because of similarities between the 2009 influenza A subtype H1N1 virus and the 1976 influenza A/NJ virus many countries established surveillance systems for vaccine-related adverse effects on human health. A possible link between the 2009 H1N1 flu vaccine and Guillain–Barré Syndrome cases was studied in Europe and the United States.<ref>{{cite book |first=Archana |last=Chatterjee |title=Vaccinophobia and Vaccine Controversies of the 21st Century |publisher=Springer Science & Business Media |year=2013 |pages=325 |isbn=9781461474388}}</ref>

===Blood transfusion===
After the introduction of [[Medicine:COVID-19 vaccine|COVID-19 vaccine]]s, vaccine hesitant people have at times demanded that they get donor blood from donors that have not received the vaccine. In the US and Canada, blood centers do not keep data on whether a donor has been COVID-19 infected or vaccinated, and in August 2021 it was estimated that 60-70% of US blood donors had COVID-19 antibodies. Research director [[Biography:Timothy Caulfield|Timothy Caulfield]] said that "This really highlights, I think, how powerful misinformation can be. It can really have an impact in a way that can be dangerous ... There is no evidence to support these concerns."<ref name="Skeptical of coronavirus shots">{{cite news |last1=Aleccia |first1=JoNel |title=Skeptical of coronavirus shots, some patients demand blood transfusions only from the unvaccinated |url=https://www.washingtonpost.com/health/skeptical-of-coronavirus-shots-some-patients-demand-blood-transfusions-only-from-the-unvaccinated/2021/08/20/17635a9e-003f-11ec-ba7e-2cf966e88e93_story.html |access-date=9 December 2022 |newspaper=Washington Post |date=21 August 2021}}</ref><ref name="Doctors seeing resistance to blood transfusions">{{cite news |last1=Lee |first1=Jennifer |title=Doctors seeing resistance to blood transfusions over unfounded COVID vaccine concerns |url=https://www.cbc.ca/news/canada/calgary/alberta-blood-transfusions-resistance-covid-1.6613841 |access-date=9 December 2022 |work=CBC.ca|date=13 October 2022}}</ref><ref name="Covid misinformation ignites" />

As of August 2021, such demands are rare in the US.<ref name="Skeptical of coronavirus shots" /> Doctors in Alberta, Canada, warned in November 2022 that the demands were becoming more common.<ref name="Covid misinformation ignites">{{cite web |last1=Robinson |first1=Rebekah |title=Covid misinformation ignites a battle over blood in a Canadian province |url=https://www.codastory.com/waronscience/covid-misinformation-ignites-a-battle-over-blood-in-a-canadian-province/ |website=Coda Media |access-date=9 December 2022 |date=16 November 2022}}</ref>

In Italy and New Zealand, parents have gone to court to stop their children's urgent heart surgery, unless COVID-19 vaccine free blood was provided. In both cases the parents were ruled against, though they stated that they could provide willing donors they found acceptable.<ref name="Italian parents lose appeal">{{cite news |last1=Barbarani |first1=Sofia |title=Italian parents lose appeal over unvaccinated blood transfusion for child's surgery |url=https://www.independent.co.uk/news/world/europe/italy-unvaccinated-blood-child-heart-surgery-b2010414.html |access-date=9 December 2022 |work=The Independent |date=8 February 2022 |language=en}}</ref><ref>{{cite web |title=Blood donor case: Baby who had heart op against parents' wishes is 'doing well' |url=https://www.stuff.co.nz/national/health/300760872/blood-donor-case-baby-who-had-heart-op-against-parents-wishes-is-doing-well |website=Stuff |access-date=9 December 2022 |language=en |date=9 December 2022}}</ref><ref name="Donor blood case might deter">{{cite web |last1=Sommerville |first1=Troels |title=Donor blood case might deter some from taking kids to doctor - ethics professor |url=https://www.stuff.co.nz/national/130711032/donor-blood-case-might-deter-some-from-taking-kids-to-doctor--ethics-professor?rm=a&cx_rm-ctrl=true |website=Stuff |access-date=9 December 2022 |language=en |date=8 December 2022}}</ref> The [[Medicine:New Zealand Blood Service|New Zealand Blood Service]] does not label blood according to the donor's COVID-19 vaccine history,<ref name="Parents refuse use of 'vaccine-tainted' donor blood">{{cite news |title=Parents refuse use of 'vaccine-tainted' donor blood for baby's operation |url=https://www.jpost.com/international/article-724046 |access-date=11 December 2022 |work=The Jerusalem Post |date=4 December 2022}}</ref> and as of 2022, about 90% of New Zealand's population over twelve years of age has had two COVID-19 vaccinations.<ref name="New Zealand court takes guardianship">{{cite news |last1=Magramo |first1=Kathleen |title=New Zealand court takes guardianship of baby after parents refuse vaccinated blood for heart surgery |url=https://edition.cnn.com/2022/12/07/asia/new-zealand-covid-vaccine-donor-blood-baby-scn-intl-hnk/index.html |access-date=9 December 2022 |work=CNN |date=7 December 2022 |language=en}}</ref> In another Italian case, a blood transfusion for a sick 90-year-old man was refused by his two daughters, due to vaccine hesitancy concerns.<ref name="Italian parents lose appeal" /> Another New Zealand couple stated that they were trying to arrange their child to have her next heart surgery in India, to avoid her being given blood from COVID-19 vaccinated donors.<ref name="Second set of parents seeks">{{cite news |last1=Earley |first1=Melanie |title=Second set of parents seeks 'unvaccinated' blood for baby's heart surgery |url=https://www.stuff.co.nz/national/health/130748678/second-set-of-parents-seeks-unvaccinated-blood-for-babys-heart-surgery |access-date=13 December 2022 |work=Stuff |date=13 December 2022 |language=en}}</ref>

===Other safety concerns===
Other safety concerns about vaccines have been promoted on the Internet, in informal meetings, in books, and at symposia. These include hypotheses that vaccination can cause epileptic seizures, [[Medicine:Allergy|allergies]], multiple sclerosis, and [[Medicine:Autoimmune disease|autoimmune disease]]s such as [[Medicine:Diabetes mellitus type 1|type{{spaces}}1 diabetes]], as well as hypotheses that vaccinations can transmit [[Medicine:Bovine spongiform encephalopathy|bovine spongiform encephalopathy]], [[Biology:Hepatitis C virus|hepatitis C virus]], and [[Biology:HIV|HIV]]. These hypotheses have been investigated, with the conclusion that currently used vaccines meet high safety standards and that criticism of vaccine safety in the popular press is not justified.<ref name="Marshall2013" /><ref name="Schneeweiss">{{Cite journal |vauthors=Schneeweiss B, Pfleiderer M, Keller-Stanislawski B |date=August 2008 |title=Vaccination safety update |journal=Deutsches Ärzteblatt International |volume=105 |issue=34–35 |pages=590–95 |doi=10.3238/arztebl.2008.0590 |pmc=2680557 |pmid=19471677}}</ref><ref name="Mailand2017">{{Cite journal |last1=Mailand |first1=MT |last2=Frederiksen |first2=JL |date=June 2017 |title=Vaccines and multiple sclerosis: a systematic review. |journal=Journal of Neurology |volume=264 |issue=6 |pages=1035–50 |doi=10.1007/s00415-016-8263-4 |pmid=27604618 |s2cid=4005599}}</ref><ref name="Rewers2016">{{Cite journal |last1=Rewers |first1=M |last2=Ludvigsson |first2=J |date=June 2016 |title=Environmental risk factors for type 1 diabetes. |journal=Lancet |volume=387 |issue=10035 |pages=2340–48 |doi=10.1016/S0140-6736(16)30507-4 |pmc=5571740 |pmid=27302273}}</ref> Large well-controlled epidemiologic studies have been conducted and the results do not support the hypothesis that vaccines cause chronic diseases. Furthermore, some vaccines are probably more likely to prevent or modify than cause or exacerbate autoimmune diseases.<ref name="Hackett-Offit">{{Cite journal |last1=Offit, Paul A. |last2=Hackett, Charles J. |year=2003 |title=Addressing Parents' Concerns: Do Vaccines Cause Allergic or Autoimmune Diseases? |journal=Pediatrics |volume=111 |issue=3 |pages=653–59 |doi=10.1542/peds.111.3.653 |pmid=12612250 |doi-access=|s2cid=10695185 }}</ref><ref name="Elwood2018">{{Cite journal |last1=Elwood |first1=JM |last2=Ameratunga |first2=R |date=September 2018 |title=Autoimmune diseases after hepatitis B immunization in adults: Literature review and meta-analysis, with reference to 'autoimmune/autoinflammatory syndrome induced by adjuvants' (ASIA). |journal=Vaccine |type=Systematic Review & Meta-Analysis |volume=36 |issue=38 |pages=5796–802 |doi=10.1016/j.vaccine.2018.07.074 |pmid=30100071|s2cid=51967163 }}</ref> Another common concern parents often have is about the pain associated with administering vaccines during a doctor's office visit.<ref name="Edwards2016" /> This may lead to parental requests to space out vaccinations; however, studies have shown a child's stress response is not different when receiving one vaccination or two. The act of spacing out vaccinations may actually lead to more stressful stimuli for the child.<ref name="Smith2015" />

== Psychology ==
The rise in vaccine hesitancy has led to research on the psychology of those who oppose vaccines. A 24-nation investigation led by the University of Queensland and reported in ''Health Psychology'' in 2018 found that the largest psychological factors leading to anti-vaccination attitudes were [[Unsolved:Conspiracy theory|conspiratorial thinking]], [[Social:Reactance (psychology)|reactance]], disgust regarding blood or needles, and individualistic or hierarchical worldviews. In contrast, demographic variables were not significant.<ref>{{Cite journal|last1=Hornsey|first1=Matthew J.|last2=Harris|first2=Emily A.|last3=Fielding|first3=Kelly S.|date=2018|title=The psychological roots of anti-vaccination attitudes: A 24-nation investigation.|url=http://doi.apa.org/getdoi.cfm?doi=10.1037/hea0000586|journal=Health Psychology|language=en|volume=37|issue=4|pages=307–315|doi=10.1037/hea0000586|pmid=29389158|s2cid=3965857|issn=1930-7810}}</ref>

Researchers have also investigated the psychological roots of vaccine hesitancy with regard to specific vaccines. For instance, a 2021 study published in ''Nature Communications'' investigated psychological characteristics associated with COVID-19 vaccine hesitancy and resistance in Ireland and the UK. The study found that vaccine hesitant or resistant respondents in the two countries varied across socio-demographic and health-related variables, however, they were similar in range of psychological factors. Such respondents were less likely to obtain information about the pandemic from authoritative and traditional media sources and demonstrated similar skepticism towards these sources compared to respondents who accepted the vaccine.<ref>{{Cite journal|last1=Murphy|first1=Jamie|last2=Vallières|first2=Frédérique|last3=Bentall|first3=Richard P.|last4=Shevlin|first4=Mark|last5=McBride|first5=Orla|last6=Hartman|first6=Todd K.|last7=McKay|first7=Ryan|last8=Bennett|first8=Kate|last9=Mason|first9=Liam|last10=Gibson-Miller|first10=Jilly|last11=Levita|first11=Liat|date=2021-01-04|title=Psychological characteristics associated with COVID-19 vaccine hesitancy and resistance in Ireland and the United Kingdom|url=http://dx.doi.org/10.1038/s41467-020-20226-9|journal=Nature Communications|volume=12|issue=1|page=29|doi=10.1038/s41467-020-20226-9|pmid=33397962|pmc=7782692|bibcode=2021NatCo..12...29M|issn=2041-1723}}</ref>

=== Fear of needles ===
Blood-injection-injury phobia and general fear of needles and injections can lead people to avoid vaccinations. One survey conducted in January and February 2021 estimated this was responsible for 10% of the COVID-19 vaccine hesitancy in the UK at the time.<ref name="Freeman">{{cite news|author=Daniel Freeman|date=16 June 2021|title=Needle phobia could be the cause of 10% of COVID vaccine hesitancy in the UK – new research|website=The Conversation|url=https://theconversation.com/needle-phobia-could-be-the-cause-of-10-of-covid-vaccine-hesitancy-in-the-uk-new-research-162678}}</ref><ref name=":4">{{cite journal|author1=Daniel Freeman|author2=Bao Sheng Loe|author3=Ly-Mee Yu|author4=Jason Freeman|author5=Andrew Chadwick|author6=Cristian Vaccari|date=16 May 2021|title=Effects of different types of written vaccination information on COVID-19 vaccine hesitancy in the UK (OCEANS-III): a single-blind, parallel-group, randomised controlled trial|journal=The Lancet|volume=6|issue=6|pages=e416–e427|doi=10.1016/S2468-2667(21)00096-7|pmc=8116130|pmid=33991482}}</ref> A 2012 survey of American parents found that a fear of needles was the most common reason for adolescents to forgo their second dose of a [[Medicine:HPV vaccine|HPV vaccine]].<ref name="Baxter">{{cite web|author=Amy Baxter m|date=11 Jun 2021|title=Over half of adults unvaccinated for COVID-19 fear needles – here's what's proven to help|url=https://theconversation.com/over-half-of-adults-unvaccinated-for-covid-19-fear-needles-heres-whats-proven-to-help-161636|website=The Conversation}}</ref><ref name=":5">{{cite journal|last1=Clark|first1=Sarah|last2=Cowan|first2=Anne|last3=Filipp|first3=Stephanie|last4=Fisher|first4=Allison|last5=Stokley|first5=Shannon|date=1 May 2016|title=Understanding Non-Completion of the Human Papillomavirus Vaccine Series: Parent-Reported Reasons for Why Adolescents Might Not Receive Additional Doses, United States, 2012|journal=Public Health Reports|volume=131|issue=3|pages=390–395|doi=10.1177/003335491613100304|pmc=4869083|pmid=27252558}}</ref>

Various treatments for fear of needles can help overcome this problem, from offering pain reduction at the time of injection to long-term behavioral therapy.<ref name="Baxter" /> Tensing the stomach muscles can help avoid fainting, swearing can reduce perceived pain, and distraction can also improve the perceived experience, such as by pretending to cough, performing a visual task, watching a video, or playing a video game.<ref name="Baxter" />
To avoid dissuading people who have a needle phobia, vaccine update researchers recommend against using pictures of needles, people getting an injection, or faces displaying negative emotions (like a crying baby) in promotional materials. Instead, they recommend medically accurate photos depicting smiling, diverse people with bandages, vaccination cards, or a rolled-up sleeve; depicting vials instead of needles; and depicting the people who develop and test vaccines.<ref name=":6">{{cite web|author1=Holly Seale|author2=Jessica Kaufman|date=8 April 2021|title=Pictures of COVID injections can scare the pants off people with needle phobias. Use these instead|url=https://theconversation.com/pictures-of-covid-injections-can-scare-the-pants-off-people-with-needle-phobias-use-these-instead-157963|website=The Conversation}}</ref> Development of vaccines that can be administered orally or with a [[Engineering:Jet injector|jet injector]] can also avoid triggering the fear of needles.<ref name=":7">{{cite web|author1=Vasso Apostolopoulos|author2=Maja Husaric|author3=Maximilian de Courten|date=30 September 2020|title=A COVID-19 vaccine may come without a needle, the latest vaccine to protect without jabbing|url=https://theconversation.com/a-covid-19-vaccine-may-come-without-a-needle-the-latest-vaccine-to-protect-without-jabbing-146564|website=The Conversation}}</ref>

== Malpractice and fraud ==

===CIA fake vaccination clinic===
In Pakistan, the CIA ran a fake vaccination clinic in an attempt to locate [[Biography:Osama bin Laden|Osama bin Laden]].<ref name=":2">{{Cite journal |last=Kennedy |first=Jonathan |date=October 2017 |title=How Drone Strikes and a Fake Vaccination Program Have Inhibited Polio Eradication in Pakistan: An Analysis of National Level Data |journal=International Journal of Health Services: Planning, Administration, Evaluation |volume=47 |issue=4 |pages=807–25 |doi=10.1177/0020731417722888 |issn=1541-4469 |pmid=28764582 |s2cid=25844860 |url=http://qmro.qmul.ac.uk/xmlui/handle/123456789/25135}}</ref><ref>{{Cite news |last=McNeil |first=Donald G. Jr. |date=2012-07-09 |title=C.I.A. Vaccine Ruse May Have Harmed the War on Polio |language=en-US |work=The New York Times |url=https://www.nytimes.com/2012/07/10/health/cia-vaccine-ruse-in-pakistan-may-have-harmed-polio-fight.html|access-date=2020-07-03 |issn=0362-4331}}</ref> As a direct consequence, there have been several attacks and deaths among vaccination workers. Several Islamist preachers and militant groups, including some factions of the [[Religion:Taliban|Taliban]], view vaccination as a plot to kill or sterilize Muslims.<ref>{{Cite news |url=https://www.npr.org/sections/goatsandsoda/2018/01/23/580002283/pakistan-raises-its-guard-after-two-polio-vaccinators-are-gunned-down |title=Pakistan Raises Its Guard After 2 Polio Vaccinators Are Gunned Down |newspaper=NPR|date=January 23, 2018 |last1=Aizenman |first1=Nurith }}</ref> Efforts to eradicate polio have furthermore been disrupted by [[Social:Drone strikes in Pakistan|American drone strikes]].<ref name=":2" /> Pakistan is among the only countries where polio remained endemic as of 2015.<ref name="Iqbal 2021">{{cite web | last=Iqbal | first=Hala | title=How the CIA's fake Hepatitis B vaccine program in Pakistan helped fuel vaccine distrust | website=Vox | date=1 February 2021 | url=https://www.vox.com/first-person/22256595/vaccine-covid-pakistan-cia-program | access-date=19 February 2023}}</ref>

===Fake COVID-19 vaccines===
In July 2021, Indian police arrested 14 people for administering doses of [[Medicine:Saline|saline solution]] instead of the [[Medicine:Oxford–AstraZeneca COVID-19 vaccine|AstraZeneca vaccine]] at nearly a dozen private vaccination sites in Mumbai. The organizers, including medical professionals, charged between $10 and $17 for each dose, and more than 2,600 people paid to receive what they thought was the vaccine.<ref>{{Cite news|last=Kumar|first=Hari|date=2021-07-04|title=Indian police investigate whether scammers gave thousands of shots of salt water instead of vaccine.|language=en-US|work=The New York Times|url=https://www.nytimes.com/2021/07/04/world/asia/india-covid-vaccine-scam.html |archive-url=https://ghostarchive.org/archive/20211228/https://www.nytimes.com/2021/07/04/world/asia/india-covid-vaccine-scam.html |archive-date=2021-12-28 |url-access=limited|access-date=2021-07-07|issn=0362-4331}}{{cbignore}}</ref><ref>{{Cite news|title=Thousands Given Fake Vaccines Through Scam In India|url=https://www.npr.org/2021/07/09/1014512227/thousands-given-fake-vaccines-through-scam-in-india|access-date=2021-07-10|website=NPR.org|language=en}}</ref> The federal government downplayed the scandal, claiming these cases were isolated. [[Company:McAfee|McAfee]] stated India was among the top countries to have been targeted by fake apps to lure people with a promise of vaccines.<ref>{{Cite web|last=|first=|title=India: Fake vaccines undermine fight against COVID {{!}} DW {{!}} 01.07.2021|url=https://www.dw.com/en/india-fake-vaccines-undermine-fight-against-covid/a-58122010|access-date=2021-07-10|website=Deutsche Welle|language=en-GB}}</ref>

In Bhopal, slum residents were misled into thinking they would get an approved [[Medicine:COVID-19|COVID-19]] vaccine, but instead were actually part of an experimental clinical trial for the domestic vaccine [[Medicine:Covaxin|Covaxin]]. Only 50% of participants in the trials received a vaccine with the rest receiving a [[Medicine:Placebo|placebo]]. One participant stated, "...I didn't know that there was a possibility you could get a water shot."<ref>{{Cite web|author=Esha Mitra and Julia Hollingsworth|title=More than a dozen slum residents in an Indian city say they didn't know they were part of a clinical vaccine trial|url=https://www.cnn.com/2021/02/25/asia/india-vaccine-trials-covid-ethics-intl-dst-hnk/index.html|access-date=2021-07-11|website=CNN|date=February 26, 2021 }}</ref><ref>{{Cite web|last=Bhuyan|first=Anoo|date=2021-01-14|title=How Covaxin Trial Participants in Bhopal Were Misled|url=https://science.thewire.in/health/peoples-hospital-bhopal-covaxin-clinical-trials-exploitation-ethics-ground-report/|access-date=2021-07-11|website=The Wire Science|language=en-GB}}</ref>

=== Unethical human experimentation and medical racism ===
Some people in groups experiencing medical racism are less willing to trust doctors and modern medicine due to real historical incidents of unethical human experimentation and involuntary sterilization. Famous examples include drug trials in Africa without informed consent, the [[Medicine:Guatemala syphilis experiments|Guatemala syphilis experiments]],<ref>{{Cite journal|title=Moving the needle on racial disparity: COVID-19 vaccine trust and hesitancy|first1=Cheryl|last1=Lin|first2=Pikuei|last2=Tu|first3=Thomas C.|last3=Terry|date=January 3, 2022|journal=Vaccine|volume=40|issue=1|pages=5–8|doi=10.1016/j.vaccine.2021.11.010|pmid=34839990|pmc=8604693}}</ref><ref>{{Cite journal|title=First, Do No Harm: The US Sexually Transmitted Disease Experiments in Guatemala|first1=Michael A.|last1=Rodriguez|first2=Robert|last2=García|date=December 2, 2013|journal=American Journal of Public Health|volume=103|issue=12|pages=2122–2126|doi=10.2105/AJPH.2013.301520|pmid=24134370|pmc=3828982}}</ref> the [[Medicine:Tuskegee Syphilis Study|Tuskegee Syphilis Study]], the culturing of cells from Henrietta Lacks without consent, and Nazi human experimentation.

To overcome this type of distrust, experts recommend including representative samples of majority and minority populations in drug trials, including minority groups in study design, being diligent about informed consent, and being transparent about the process of drug design and testing.<ref>{{cite web |url=https://time.com/5925074/black-americans-covid-19-vaccine-distrust/ |title=Fueled by a History of Mistreatment, Black Americans Distrust the New COVID-19 Vaccines |author=Dezimey Kum  |date=28 Dec 2020 |magazine=Time}}</ref>

==Vaccine myths==
Several vaccination myths contribute to parental concerns and vaccine hesitancy. These include the alleged superiority of natural infection when compared to vaccination, questioning whether the diseases vaccines prevent are dangerous, whether vaccines pose moral or religious dilemmas, suggesting that vaccines are not effective, proposing unproven or ineffective approaches as alternatives to vaccines, and conspiracy theories that center on mistrust of the government and medical institutions.<ref name="Jacobson2020"/>

===Autism===
{{Main|Unsolved:Vaccines and autism}}

<!--summary at Vaccines and autism/Summary-->
The idea of a link between vaccines and autism has been extensively investigated and conclusively shown to be false.<ref>{{Cite journal |last1=Taylor |first1=Luke E. |last2=Swerdfeger |first2=Amy L. |last3=Eslick |first3=Guy D. |date=2014-06-17 |title=Vaccines are not associated with autism: an evidence-based meta-analysis of case-control and cohort studies |journal=Vaccine |volume=32 |issue=29 |pages=3623–29 |doi=10.1016/j.vaccine.2014.04.085 |issn=1873-2518 |pmid=24814559}}</ref><ref name="Smith2017">{{Cite journal |last1=Smith |first1=IM |last2=MacDonald |first2=NE |date=August 2017 |title=Countering evidence denial and the promotion of pseudoscience in autism spectrum disorder |journal=Autism Research |type=Review |volume=10 |issue=8 |pages=1334–37 |doi=10.1002/aur.1810 |pmid=28544626 |s2cid=205456548}}</ref> The [[Philosophy:Scientific consensus|scientific consensus]] is that there is no relationship, causal or otherwise, between vaccines and incidence of autism,<ref name="BH">{{Cite journal |last1=Bonhoeffer |first1=Jan |last2=Heininger |first2=Ulrich |date=June 2007 |title=Adverse events following immunization: perception and evidence |journal=Current Opinion in Infectious Diseases |volume=20 |issue=3 |pages=237–46 |doi=10.1097/QCO.0b013e32811ebfb0 |pmid=17471032 |s2cid=40669829}}</ref><ref>{{Cite news |url=https://www.theguardian.com/society/2010/feb/02/lancet-retracts-mmr-paper |title=Lancet retracts 'utterly false' MMR paper |last=Boseley |first=Sarah |date=February 2, 2010 |work=The Guardian |access-date=February 2, 2010 |name-list-style=vanc}}</ref><ref>{{Cite journal |vauthors=Taylor LE, Swerdfeger AL, Eslick GD |date=June 2014 |title=Vaccines are not associated with autism: an evidence-based meta-analysis of case-control and cohort studies |journal=Vaccine |volume=32 |issue=29 |pages=3623–29 |doi=10.1016/j.vaccine.2014.04.085 |pmid=24814559}}</ref> and vaccine ingredients do not cause autism.<ref>{{Cite web |url=https://www.cdc.gov/vaccinesafety/concerns/autism.html |title=Vaccines Do Not Cause Autism Concerns |date=2018-12-12 |website=Centers for Disease Control and Prevention |language=en-us |access-date=2019-02-07}}</ref>

Nevertheless, the anti-vaccination movement continues to promote myths, [[Unsolved:Conspiracy theory|conspiracy theories]], and misinformation linking the two.<ref>{{Cite journal |date=February 2019 |title=How autism myths came to fuel anti-vaccination movements |url=https://www.popsci.com/timeline-autism-myth-anti-vaccine |journal=Popular Science |language=en}}</ref> A developing tactic appears to be the "promotion of irrelevant research [as] an active aggregation of several questionable or peripherally related research studies in an attempt to justify the science underlying a questionable claim".<ref>{{Cite journal |last1=Foster |first1=Craig A. |last2=Ortiz |first2=Sarenna M. |date=2017 |title=Vaccines, Autism, and the Promotion of Irrelevant Research: A Science-Pseudoscience Analysis |url=https://www.csicop.org/si/show/vaccines_autism_and_the_promotion_of_irrelevant_research_a_science-pseudosc |archive-url=https://web.archive.org/web/20181006204019/https://www.csicop.org/si/show/vaccines_autism_and_the_promotion_of_irrelevant_research_a_science-pseudosc |url-status=dead |archive-date=2018-10-06 |journal=[[Unsolved:Skeptical Inquirer|Skeptical Inquirer]] |volume=41 |issue=3 |pages=44–48 |access-date=6 October 2018}}</ref>

===Vaccination during illness===
Many parents are concerned about the safety of vaccination when their child is sick.<ref name="Smith2015" /> Moderate to severe acute illness with or without a fever is indeed a precaution when considering vaccination.<ref name="Smith2015" /> Vaccines remain effective during childhood illness.<ref name="Smith2015" /> The reason vaccines may be withheld if a child is moderately to severely ill is because certain expected side effects of vaccination (e.g. [[Medicine:Fever|fever]] or rash) may be confused with the progression of the illness.<ref name="Smith2015" /> It is safe to administer vaccines to well-appearing children who are mildly ill with the [[Medicine:Common cold|common cold]].<ref name="Smith2015" />

===Natural infection===
Another common anti-vaccine myth is that the [[Biology:Immune system|immune system]] produces a better immune protection in response to natural infection when compared to vaccination.<ref name="Smith2015" /> However, strength and duration of immune protection gained varies by both disease and vaccine, with some vaccines giving better protection than natural infection.  For example, the [[Medicine:HPV vaccine|HPV vaccine]] generates better immune protection than natural infection due to the vaccine containing higher concentrations of a viral coat protein, while also not containing proteins the HPV viruses use to inhibit immune response.<ref name=CNN_2020-10-20 >{{ cite news | url=https://edition.cnn.com/2020/10/02/health/vaccine-better-immunity-than-infection-wellness-partner/index.html | title=A vaccine can provide better immunity than an actual infection. Here's why.  | last=Shivkumar | first=Maitreyi | newspaper=CNN | date=2020-10-20 | quote=For instance, the human papillomavirus (HPV) vaccine elicits a stronger immune response than infection by the virus itself. One reason for this is that the vaccine contains high concentrations of a viral coat protein, more than what would occur in a natural infection. This triggers strongly neutralizing antibodies, making the vaccine very effective at preventing infection. The natural immunity against HPV is especially weak, as the virus uses various tactics to evade the host immune system. Many viruses, including HPV, have proteins that block the immune response or simply lie low to avoid detection. Indeed, a vaccine that provides accessible antigens in the absence of these other proteins may allow us to control the response in a way that a natural infection does not. }}</ref>

While it is true that infection with certain illnesses may produce lifelong [[Medicine:Immunity (medical)|immunity]], many natural infections do not produce lifelong immunity, while carrying a higher risk of harming a person's health than vaccines.<ref name="Smith2015" /> For example, natural varicella infection carries a higher risk of bacterial superinfection with Group A streptococci.<ref name="Smith2015" />

Natural [[Medicine:Measles|measles]] infection carries a high risk of many serious, and sometimes life-long, complications, all of which can be avoided by vaccination. Those infected with measles rarely have a symptomatic reinfection.<ref>{{cite journal | title = Recommendation of the Immunization Practices Advisory Committee (ACIP). Measles prevention | journal = MMWR. Morbidity and Mortality Weekly Report | volume = 31 | issue = 17 | pages = 217–24, 229–31 | date = May 1982 | pmid = 6804783 | url = https://www.cdc.gov/mmwr/preview/mmwrhtml/00001090.htm | author1 = Centers for Disease Control (CDC) }}</ref>

Most people survive measles, though in some cases, complications may occur. Among those that experience complications, about 1 in 4 individuals will be hospitalized and 1–2 in 1000 will die. Complications are more likely in children under age 5 and adults over age 20.<ref>{{cite web |title=Measles Complications |url=https://www.cdc.gov/measles/about/complications.html |website=Centers for Disease Control and Prevention (CDC) |access-date=14 May 2019 |date=25 February 2019}}</ref> [[Medicine:Pneumonia|Pneumonia]] is the most common fatal complication of measles infection and accounts for 56-86% of measles-related deaths.<ref>{{Cite journal |last1=Di Pietrantonj |first1=Carlo |last2=Rivetti |first2=Alessandro |last3=Marchione |first3=Pasquale |last4=Debalini |first4=Maria Grazia |last5=Demicheli |first5=Vittorio |date=2021-11-22 |title=Vaccines for measles, mumps, rubella, and varicella in children |journal=The Cochrane Database of Systematic Reviews |volume=2021 |issue=11 |pages=CD004407 |doi=10.1002/14651858.CD004407.pub5 |issn=1469-493X |pmc=8607336 |pmid=34806766}}</ref>

Possible consequences of measles virus infection include laryngotracheobronchitis, sensorineural hearing loss,<ref name=Cohen2014>{{cite journal | vauthors = Cohen BE, Durstenfeld A, Roehm PC | title = Viral causes of hearing loss: a review for hearing health professionals | journal = Trends in Hearing | volume = 18 | pages = 2331216514541361 | date = July 2014 | pmid = 25080364 | pmc = 4222184 | doi = 10.1177/2331216514541361 }}</ref> and—in about 1 in 10,000 to 1 in 300,000 cases<ref name=Noyce2012>{{cite journal | vauthors = Noyce RS, Richardson CD | title = Nectin 4 is the epithelial cell receptor for measles virus | journal = Trends in Microbiology | volume = 20 | issue = 9 | pages = 429–39 | date = September 2012 | pmid = 22721863 | doi = 10.1016/j.tim.2012.05.006 }}</ref>—[[Medicine:Subacute sclerosing panencephalitis|panencephalitis]], which is usually fatal.<ref name="ninds.nih.gov">{{cite web |url=http://www.ninds.nih.gov/disorders/subacute_panencephalitis/subacute_panencephalitis.htm |title=NINDS Subacute Sclerosing Panencephalitis Information Page |access-date=2018-03-26 |url-status=live |archive-url=https://web.archive.org/web/20141017073411/http://www.ninds.nih.gov/disorders/subacute_panencephalitis/subacute_panencephalitis.htm |archive-date=2014-10-17 }} "NINDS Subacute Sclerosing Panencephalitis Information Page"</ref> Acute measles encephalitis is another serious risk of measles virus infection. It typically occurs two days to one week after the measles rash breaks out and begins with very high fever, severe headache, [[Medicine:Convulsion|convulsion]]s and altered mentation. A person with measles encephalitis may become [[Medicine:Coma|coma]]tose, and death or brain injury may occur.<ref>{{MerckManual|14|193|b|}}</ref>

The measles virus can deplete previously acquired [[Biology:Immunological memory|immune memory]] by killing cells that make antibodies, and thus weakens the immune system which can cause deaths from other diseases.<ref name=Amnesia>{{cite web |last1=GRIFFIN |first1=ASHLEY HAGEN |title=Measles and Immune Amnesia |url=https://asm.org/Articles/2019/May/Measles-and-Immune-Amnesia |website=asm.org |publisher=American Society for Microbiology |access-date=18 January 2020 |archive-url=https://archive.today/20200118042959/https://asm.org/Articles/2019/May/Measles-and-Immune-Amnesia |archive-date=18 January 2020 |date=18 May 2019 |url-status=live}}</ref><ref name="Mina 2019">{{cite journal | vauthors = Mina MJ, Kula T, Leng Y, Li M, de Vries RD, Knip M, Siljander H, Rewers M, Choy DF, Wilson MS, Larman HB, Nelson AN, Griffin DE, de Swart RL, Elledge SJ | display-authors = 6 | title = Measles virus infection diminishes preexisting antibodies that offer protection from other pathogens | journal = Science | volume = 366 | issue = 6465 | pages = 599–606 | date = 1 November 2019 | pmid = 31672891 | doi = 10.1126/science.aay6485 | pmc = 8590458 | issn=0036-8075 | bibcode = 2019Sci...366..599M | doi-access = free }}</ref><ref name=Nature>{{cite journal|title=Measles erases immune 'memory' for other diseases|url=https://www.nature.com/articles/d41586-019-03324-7|journal=Nature|access-date=3 November 2019|date=31 October 2019|doi=10.1038/d41586-019-03324-7|last1=Guglielmi|first1=Giorgia|pmid=33122832|s2cid=208489179}}</ref> [[Biology:Immunosuppression|Suppression of the immune system]] by measles lasts about two years and has been epidemiologically implicated in up to 90% of childhood deaths in [[Social:Third World|third world]] countries, and historically may have caused rather more deaths in the United States, the UK and Denmark than were directly caused by measles.<ref name="pmid25954009" >{{cite journal |title=Long-term measles-induced immunomodulation increases overall childhood infectious disease mortality |journal=Science |date=May 2015 |doi=10.1126/science.aaa3662|pmid=25954009|pmc=4823017 |bibcode=2015Sci...348..694M |vauthors = Mina MJ, Metcalf CJ, de Swart RL, Osterhaus AD, Grenfell BT |volume=348 |issue=6235 |pages=694–9 |doi-access=free}}</ref> Although the measles vaccine contains an attenuated strain, it does not deplete immune memory.<ref name="Mina 2019"/>

===HPV vaccine===
The idea that the [[Medicine:HPV vaccine|HPV vaccine]] is linked to increased sexual behavior is not supported by scientific evidence. A review of nearly 1,400 adolescent girls found no difference in teen pregnancy, the incidence of [[Medicine:Sexually transmitted infection|sexually transmitted infection]], or contraceptive counseling regardless of whether they received the HPV vaccine.<ref name="Smith2015" /> Thousands of Americans die each year from cancers preventable by the vaccine.<ref name="Smith2015" />

There remains a disproportionate rate of HPV-related cancers amongst [[Social:Latinx|LatinX]] populations, leading researchers to explore how messaging may be made more effective to address vaccine hesitancy.<ref>{{Cite journal |last1=Reno |first1=Jenna E. |last2=Dempsey |first2=Amanda F. |date=2022-02-18 |title=Promoting HPV vaccination among Latinx: an application of the extended parallel processing model |url=https://link.springer.com/10.1007/s10865-022-00293-7 |journal=Journal of Behavioral Medicine |volume=46 |issue=1–2 |pages=324–334 |language=en |doi=10.1007/s10865-022-00293-7 |pmid=35178652 |s2cid=246905792 |issn=0160-7715}}</ref>

===Vaccine schedule===
Other concerns have been raised about the vaccine schedule recommended by the Advisory Committee on Immunization Practices (ACIP). The immunization schedule is designed to protect children against preventable diseases when they are most vulnerable. The practice of delaying or spacing out these vaccinations increases the amount of time the child is susceptible to these illnesses.<ref name="Smith2015" /> Receiving vaccines on the schedule recommended by the ACIP is not linked to autism or developmental delay.<ref name="Smith2015" />

==Events following reductions in vaccination==
[[File:GAVI Global Alliance Save Childrens Lives pledging conference (5827417113).jpg|thumb |Campaigners in [[Place:London|London]] for expanded vaccination in the developing world]]

In several countries, reductions in the use of some vaccines were followed by increases in the diseases' morbidity and mortality.<ref name="Gangarosa_pertussis" /><ref name="Allen_herd" /> According to the Centers for Disease Control and Prevention, continued high levels of vaccine coverage are necessary to prevent a resurgence of diseases that have been nearly eliminated.<ref name="CDC_stop">{{Cite web |url=https://www.cdc.gov/vaccines/vac-gen/whatifstop.htm |title=What would happen if we stopped vaccinations? |date=2007-06-12 |publisher=Centers for Disease Control and Prevention |access-date=2008-04-25}}</ref> Pertussis remains a major health problem in developing countries, where mass vaccination is not practiced; the World Health Organization estimates it caused 294,000 deaths in 2002.<ref>{{Cite book |title=Epidemiology and Prevention of Vaccine-Preventable Diseases |last=Centers for Disease Control and Prevention |publisher=Public Health Foundation |year=2007 |isbn=978-0-01-706605-3 |veditors=Atkinson W, Hamborsky J, McIntyre L, Wolfe S |location=Washington, DC |chapter=Pertussis |chapter-url=https://www.cdc.gov/vaccines/pubs/pinkbook/downloads/pert.pdf}}</ref> Vaccine hesitancy has contributed to the resurgence of preventable disease. For example, in 2019, the number of measles cases increased by thirty percent worldwide and many cases occurred in countries that had nearly eliminated measles.<ref name="Jacobson2020"/>

===Stockholm, smallpox (1873–74)===
An anti-vaccination campaign motivated by religious objections, concerns about effectiveness, and concerns about individual rights led to the vaccination rate in Stockholm dropping to just over 40%, compared to about 90% elsewhere in Sweden. A major smallpox [[Medicine:Epidemic|epidemic]] began there in 1873. It led to a rise in vaccine uptake and an end of the epidemic.<ref>{{Cite journal |vauthors=Nelson MC, Rogers J |date=December 1992 |title=The right to die? Anti-vaccination activity and the 1874 smallpox epidemic in Stockholm |journal=Social History of Medicine |volume=5 |issue=3 |pages=369–88 |doi=10.1093/shm/5.3.369 |pmid=11645870}}</ref>

===UK, pertussis (1970s–80s)===
In a 1974 report ascribing 36 reactions to whooping cough (pertussis) vaccine, a prominent public-health academic claimed that the vaccine was only marginally effective and questioned whether its benefits outweigh its risks, and extended television and press coverage caused a scare. Vaccine uptake in the UK decreased from 81% to 31%, and pertussis epidemics followed, leading to the deaths of some children. The mainstream medical opinion continued to support the effectiveness and safety of the vaccine; public confidence was restored after the publication of a national reassessment of vaccine efficacy. Vaccine uptake then increased to levels above 90%, and disease incidence declined dramatically.<ref name="Gangarosa_pertussis">{{Cite journal |vauthors=Gangarosa EJ, Galazka AM, Wolfe CR, Phillips LM, Gangarosa RE, Miller E, Chen RT |date=January 1998 |title=Impact of anti-vaccine movements on pertussis control: the untold story |journal=Lancet |volume=351 |issue=9099 |pages=356–61 |doi=10.1016/S0140-6736(97)04334-1 |pmid=9652634 |s2cid=35969647}}</ref>

===Sweden, pertussis (1979–96)===
In the vaccination moratorium period that occurred when Sweden suspended vaccination against whooping cough (pertussis) from 1979 to 1996, 60% of the country's children contracted the disease before the age of 10; close medical monitoring kept the death rate from whooping cough at about one per year.<ref name="Allen_herd">{{Cite journal |last=Allen A |year=2002 |title=Bucking the herd |url=http://immunize.org/exemptions/allen.htm |journal=The Atlantic |volume=290 |issue=2 |pages=40–42 |access-date=2007-11-07}}</ref>

===Netherlands, measles (1999–2000)===
<!--I'm uncertain whether religious behaviour is in the same category – this is more like a control experiment (as sometimes demanded by anti-vaccinationists) If we define a-v as actively trying to stop others from being vaccinated this group probably falls outside it, and therefore should move to the vaccination article AKM.-->
An outbreak at a religious community and school in the Netherlands resulted in three deaths and 68 hospitalizations among 2,961 cases.<ref name="auto">{{Cite journal |last=Centers for Disease Control and Prevention |date=April 2000 |title=Measles outbreak – Netherlands, April 1999 – January 2000 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/mm4914a2.htm |journal=Morbidity and Mortality Weekly Report |volume=49 |issue=14 |pages=299–303 |pmid=10825086}}</ref> The population in the several provinces affected had a high level of immunization, with the exception of [[Medicine:Vaccination and religion|one of the religious denominations]], which traditionally does not accept vaccination. Ninety-five percent of those who contracted measles were unvaccinated.<ref name="auto" />

===UK and Ireland, measles (2000)===
As a result of the [[Social:MMR vaccine controversy|MMR vaccine controversy]], vaccination rates dropped sharply in the United Kingdom after 1996.<ref name="Pepys">{{Cite journal |vauthors=Pepys MB |date=December 2007 |title=Science and serendipity |journal=Clinical Medicine |volume=7 |issue=6 |pages=562–78 |doi=10.7861/clinmedicine.7-6-562 |pmc=4954362 |pmid=18193704}}</ref> From late 1999 until the summer of 2000, there was a [[Medicine:Measles|measles]] outbreak in North Dublin, Ireland. At the time, the national immunization level had fallen below 80%, and in parts of North Dublin the level was around 60%. There were more than 100 hospital admissions from over 300 cases. Three children died and several more were gravely ill, some requiring mechanical ventilation to recover.<ref>Ireland measles outbreak:
*{{cite news |title=Measles outbreak feared |date=May 30, 2000 |work=BBC News |url=http://news.bbc.co.uk/2/hi/health/769381.stm}}
*{{cite journal |vauthors=McBrien J, Murphy J, Gill D, Cronin M, O'Donovan C, Cafferkey MT |title=Measles outbreak in Dublin, 2000 |journal=The Pediatric Infectious Disease Journal |volume=22 |issue=7 |pages=580–84 |date=July 2003 |pmid=12867830 |doi=10.1097/00006454-200307000-00002}}</ref>

===Nigeria, polio, measles, diphtheria (2001–)===
In the early first decade of the 21st century, conservative religious leaders in northern Nigeria, suspicious of [[Medicine:Medicine|Western medicine]], advised their followers not to have their children vaccinated with the oral polio vaccine. The boycott was endorsed by the governor of Kano State, and immunization was suspended for several months. Subsequently, polio reappeared in a dozen formerly polio-free neighbors of Nigeria, and genetic tests showed the virus was the same one that originated in northern Nigeria. Nigeria had become a net exporter of the poliovirus to its African neighbors. People in the northern states were also reported to be wary of other vaccinations, and Nigeria reported over 20,000 measles cases and nearly 600 deaths from measles from January through March 2005.<ref name="Clements">{{Cite journal |last1=Clements |first1=Christopher |last2=Greenough |first2=Paul |last3=Shull |first3=Diana |date=1 January 2006 |title=How Vaccine Safety can Become Political – The Example of Polio in Nigeria |journal=Current Drug Safety |volume=1 |issue=1 |pages=117–19 |doi=10.2174/157488606775252575 |pmid=18690921}}</ref> In Northern Nigeria, it is a common belief that vaccination is a strategy created by the westerners to reduce the Northerners' population. As a result of this belief, a large number of Northerners reject vaccination.<ref>{{Cite news |url=https://publichealthng.com/immunization-nigeria-challenges-benefits-prevention/ |title=Challenges of Immunization in Nigeria |last=Public Health Nigeria |date=October 2018 |access-date=2018-10-28 |publisher=PublichealthNg.com |archive-date=October 29, 2018 |archive-url=https://web.archive.org/web/20181029113729/https://publichealthng.com/immunization-nigeria-challenges-benefits-prevention/ |url-status=dead }}</ref> In 2006, Nigeria accounted for over half of all new polio cases worldwide.<ref>{{Cite web |url=http://www.polioeradication.org/content/general/casecount.pdf |title=Wild poliovirus 2000–2008 |date=2008-02-05 |publisher=Global Polio Eradication Initiative |archive-url=https://web.archive.org/web/20070927204139/http://www.polioeradication.org/content/general/casecount.pdf <!--bot retrieved archive--> |archive-date=2007-09-27 |access-date=2008-02-11}}</ref> Outbreaks continued thereafter; for example, at least 200 children died in a late-2007 measles outbreak in Borno State.<ref>{{Cite news |url=http://irinnews.org/Report.aspx?ReportId=75883 |title='Hundreds' dead in measles outbreak |date=2007-12-14 |access-date=2008-02-10 |agency=IRIN |archive-date=February 8, 2012 |archive-url=https://web.archive.org/web/20120208011542/http://irinnews.org/Report.aspx?ReportId=75883 |url-status=dead }}</ref>

===United States, measles (2005–)===
In 2000, measles was declared eliminated from the United States because the internal transmission had been interrupted for one year; the remaining reported cases were due to importation.<ref>{{Cite web |url=https://www.cdc.gov/measles/about/faqs.html |title=Frequently Asked Questions about Measles in U.S |date=2018-08-28 |publisher=Centers for Disease Control and Prevention}}</ref>

A 2005 measles outbreak in the US state of Indiana was attributed to parents who had refused to have their children vaccinated.<ref name="parker">{{Cite journal |vauthors=Parker AA, Staggs W, Dayan GH, Ortega-Sánchez IR, Rota PA, Lowe L, Boardman P, Teclaw R, Graves C, LeBaron CW |date=August 2006 |title=Implications of a 2005 measles outbreak in Indiana for sustained elimination of measles in the United States |journal=The New England Journal of Medicine |volume=355 |issue=5 |pages=447–55 |doi=10.1056/NEJMoa060775 |pmid=16885548 |s2cid=34529542|doi-access=free }}</ref>
[[File:US Measles Cases 2015-07-02.jpg|thumb|upright=1.5]]

The Centers for Disease Control and Prevention (CDC) reported that the three biggest outbreaks of measles in 2013 were attributed to clusters of people who were unvaccinated due to their philosophical or religious beliefs. As of August 2013, three pockets of outbreak{{snd}}New York City, North Carolina, and Texas{{snd}}contributed to 64% of the 159 cases of measles reported in 16 states.<ref>{{Cite news |url=https://www.cbsnews.com/8301-204_162-57602677/cdc-vaccine-philosophical-differences-driving-up-u.s-measles-rates/ |title=CDC: Vaccine "philosophical differences" driving up U.S. measles rates |last=Jaslow, Ryan |date=September 12, 2013 |access-date=September 19, 2013 |work=CBS News}}</ref><ref>{{Cite journal |last=Centers for Disease Control Prevention (CDC) |date=September 2013 |title=National, state, and local area vaccination coverage among children aged 19–35 months – United States, 2012 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6236a1.htm |journal=Morbidity and Mortality Weekly Report |volume=62 |issue=36 |pages=733–40 |pmc=4585572 |pmid=24025754}}</ref>

The number of cases in 2014 quadrupled to 644,<ref>{{Cite news |url=https://www.latimes.com/visuals/graphics/la-me-g-spread-of-disneyland-measles-outbreak-20150113-htmlstory.html |title=The spread of Disneyland measles outbreak |date=January 15, 2015 |work=Los Angeles Times |vauthors=Rañoa R, Zarracina J}}</ref> including transmission by unvaccinated visitors to Disneyland in California, during the Disneyland measles outbreak.<ref name="Alazraki11">{{Cite news |url=http://www.dailyfinance.com/2011/01/12/autism-vaccine-fraud-wakefield-cost-money-deaths/ |title=The Autism Vaccine Fraud: Dr. Wakefield's Costly Lie to Society |last=Alazraki M |date=January 12, 2011 |work=DailyFinance, AOL Money & Finance |access-date=October 18, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20111027104603/http://www.dailyfinance.com/2011/01/12/autism-vaccine-fraud-wakefield-cost-money-deaths/ |archive-date=October 27, 2011 |df=mdy-all}}</ref><ref>{{Cite news |url=https://www.theguardian.com/us-news/2015/jan/14/measles-outbreak-spreads-unvaccinated-woman-disneyland |title=Measles outbreak worsens in US after unvaccinated woman visits Disneyland |last=Glenza |first=Jessica |date=January 19, 2015 |access-date=June 1, 2015 |website=The Guardian |name-list-style=vanc}}</ref> Some 97% of cases in the first half of the year were confirmed to be due directly or indirectly to importation (the remainder were unknown), and 49% from the Philippines. More than half the patients (165 out of 288, or 57%) during that time were confirmed to be unvaccinated by choice; 30 (10%) were confirmed to have been vaccinated.<ref name="cdc2014a">{{Cite journal |vauthors=Gastañaduy PA, Redd SB, Fiebelkorn AP, Rota JS, Rota PA, Bellini WJ, Seward JF, Wallace GS |date=June 2014 |title=Measles – United States, January 1 – May 23, 2014 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6322a4.htm?s_cid=mm6322a4_w |journal=Morbidity and Mortality Weekly Report |volume=63 |issue=22 |pages=496–99 |pmc=5779360 |pmid=24898167}}</ref> The final count of measles in 2014 was 668 cases in 27 states.<ref name="CDCdata">{{Cite web |url=https://www.cdc.gov/measles/cases-outbreaks.html |title=Measles Cases and Outbreaks |last=CDC |date=June 30, 2015 |access-date=July 2, 2015}}</ref>

From January 1 to June 26, 2015, 178 people from 24 states and the District of Columbia were reported to have measles. Most of these cases (117 cases [66%]) were part of a large multi-state outbreak linked to Disneyland in California, continued from 2014. Analysis by the CDC scientists showed that the measles virus type in this outbreak (B3) was identical to the virus type that caused the large measles outbreak in the Philippines in 2014.<ref name=CDCdata/> On July 2, 2015, the first confirmed death from measles in twelve years was recorded. An immunocompromised woman in Washington State was infected and later died of [[Medicine:Pneumonia|pneumonia]] due to measles.<ref>{{Cite web |url=http://www.doh.wa.gov/Newsroom/2015NewsReleases/15119WAMeaslesRelatedDeath |title=Measles led to death of Clallam Co. woman; first in US in a dozen years |last=Press Release |date=July 2, 2015 |publisher=Washington Department of Health |access-date=July 2, 2015 |archive-date=May 7, 2019 |archive-url=https://web.archive.org/web/20190507002748/https://www.doh.wa.gov/Newsroom/2015NewsReleases/15119WAMeaslesRelatedDeath |url-status=dead }}</ref>

By July 2016, a three-month measles outbreak affecting at least 22 people was spread by unvaccinated employees of the Eloy, Arizona detention center, an Immigration and Customs Enforcement (ICE) facility owned by for-profit prison operator [[Company:CoreCivic|CoreCivic]]. Pinal County's health director presumed the outbreak likely originated with a migrant, but detainees had since received vaccinations. However convincing CoreCivic's employees to become vaccinated or demonstrate proof of immunity was much more difficult, he said.<ref>[https://www.theguardian.com/us-news/2016/jul/08/arizona-measles-outbreak-immigration-detention-workers Arizona measles outbreak: immigration workers blamed for refusing vaccines], ''{{wipe|The Guardian}}'', July 8, 2016. Retrieved March 10, 2019.</ref>

In spring 2017, a measles outbreak occurred in Minnesota. As of June 16, 78 cases of measles had been confirmed in the state, 71 were unvaccinated and 65 were Somali-Americans.<ref>{{Cite web |url=http://www.health.state.mn.us/divs/idepc/diseases/measles/ |title=Measles – Minnesota Dept. of Health |website=Health.state.mn.us |access-date=July 20, 2017 |archive-date=June 10, 2017 |archive-url=https://web.archive.org/web/20170610014848/http://www.health.state.mn.us/divs/idepc/diseases/measles/ |url-status=dead }}</ref><ref>{{Cite news |url=https://www.washingtonpost.com/national/health-science/imams-in-us-take-on-the-anti-vaccine-movement-during-ramadan/2017/05/26/8660edc6-41ad-11e7-8c25-44d09ff5a4a8_story.html |title=Measles outbreak in Minnesota surpasses last year's total for the entire country |last=Sun |first=Lena H. |date=June 1, 2017 |newspaper=The Washington Post |name-list-style=vanc}}</ref><ref>{{Cite web |url=http://www.cnn.com/2017/05/08/health/measles-minnesota-somali-anti-vaccine-bn/index.html |title=Anti-vaccine groups blamed in Minnesota measles outbreak |last=Howard |first=Jacqueline |date=8 May 2017 |website=CNN |access-date=26 May 2017 |name-list-style=vanc}}</ref><ref name=":3">{{Cite news |url=https://www.newscientist.com/article/mg23431253-200-minnesota-measles-outbreak-follows-antivaccination-campaign/ |title=Minnesota measles outbreak follows anti-vaccination campaign |date=10 May 2017 |work=New Scientist |access-date=26 May 2017 |issue=3125 |publication-date=13 May 2017 |language=en-US}}</ref><ref name=":1">{{Cite news |url=https://www.npr.org/sections/health-shots/2017/05/03/526723028/autism-fears-fueling-minnesotas-measles-outbreak |title=Unfounded Autism Fears Are Fueling Minnesota's Measles Outbreak |last=Zdechlik |first=Mark |date=3 May 2017 |work=NPR.org |access-date=26 May 2017 |language=en |name-list-style=vanc}}</ref> The outbreak has been attributed to low vaccination rates among Somali-American children, which can be traced back to 2008, when Somali parents began to express concern about disproportionately high numbers of Somali preschoolers in special education classes who were receiving services for autism spectrum disorder. Around the same time, disgraced former doctor [[Biography:Andrew Wakefield|Andrew Wakefield]] visited Minneapolis, teaming up with anti-vaccine groups to raise concerns that vaccines were the cause of autism,<ref>{{Cite news |url=https://edition.cnn.com/2017/05/08/health/measles-minnesota-somali-anti-vaccine-bn/index.html |title=Anti-vaccine groups blamed in Minnesota measles outbreak |last=Howard |first=Jacqueline |work=CNN |access-date=2018-11-13 |name-list-style=vanc}}</ref><ref>{{Cite news |url=https://www.npr.org/sections/health-shots/2017/05/03/526595475/understanding-the-history-behind-communities-vaccine-fears |title=Understanding The History Behind Communities' Vaccine Fears |last=Sohn |first=Emily |date=3 May 2017 |newspaper=NPR |access-date=February 15, 2019 |name-list-style=vanc}}</ref><ref>{{Cite journal |last=Dyer |first=Owen |date=16 May 2017 |title=Measles outbreak in Somali American community follows anti-vaccine talks |journal=BMJ |volume=357 |pages=j2378 |doi=10.1136/bmj.j2378 |pmid=28512183 |s2cid=27124692}}</ref><ref>{{Cite news |url=https://www.washingtonpost.com/national/health-science/anti-vaccine-activists-spark-a-states-worst-measles-outbreak-in-decades/2017/05/04/a1fac952-2f39-11e7-9dec-764dc781686f_story.html |title=Anti-vaccine activists spark a state's worst measles outbreak in decades |last=Sun, Lena H. |date=May 5, 2017 |newspaper={{wipe|The Washington Post}} |access-date=February 17, 2019}}</ref> despite the fact that multiple studies have shown no connection between the [[Medicine:MMR vaccine|MMR vaccine]] and [[Medicine:Autism|autism]].<ref name="Gerber" />

From fall 2018 to early 2019, New York State experienced an outbreak of over 200 confirmed measles cases. Many of these cases were attributed to ultra-Orthodox Jewish communities with low vaccination rates in areas within Brooklyn and Rockland County. State Health Commissioner Howard Zucker stated that this was the worst outbreak of measles in his recent memory.<ref>{{Cite news |url=https://www.nytimes.com/2019/01/17/nyregion/measles-outbreak-jews-nyc.html |title=New York Confronts Its Worst Measles Outbreak in Decades |last=Otterman |first=Sharon |date=2019-01-17 |work=The New York Times |access-date=2019-01-19 |language=en-US |issn=0362-4331 |name-list-style=vanc}}</ref><ref>{{Cite web |url=https://www.cnn.com/2019/01/08/health/measles-outbreak-ny-bn/index.html |title=NY tackles 'largest measles outbreak' in state's recent history |last=Howard |first=Jacqueline |website=CNN |date=January 8, 2019 |access-date=2019-01-19 |name-list-style=vanc}}</ref>

In January 2019, Washington state reported an outbreak of at least 73 confirmed cases of measles, most within Clark County, which has a higher rate of vaccination exemptions compared to the rest of the state. This led state governor Jay Inslee to declare a state of emergency, and the state's congress to introduce legislation to disallow vaccination exemption for personal or philosophical reasons.<ref>{{Cite web |url=https://www.seattletimes.com/seattle-news/amid-measles-outbreak-legislation-proposed-to-ban-vaccine-exemptions/ |title=Amid measles outbreak, legislation proposed to ban vaccine exemptions |last=Goldstein-Street |first=Jake |date=January 28, 2019 |website=The Seattle Times |access-date=January 28, 2019}}</ref><ref>{{Cite web |url=https://www.nbcnews.com/storyline/measles-outbreak/measles-outbreak-southwestern-washington-rises-50-cases-n966751 |title=Washington state is averaging more than one measles case per day in 2019 |website=NBC News|date=February 4, 2019 }}</ref><ref>{{Cite web |url=https://www.msn.com/en-ph/lifestyle/family/amid-measles-outbreak-anti-vaxx-parents-have-put-others-e2-80-99-babies-at-risk/ar-BBTbIBq |title=Amid Measles Outbreak, Anti-Vaxx Parents Have Put Others' Babies At Risk |website=MSN}}</ref><ref>{{Cite web |url=https://www.vox.com/2019/1/27/18199514/measles-outbreak-2018-clark-county-washington |title=Washington declared a public health emergency over measles. Thank vaccine-refusing parents. |last=Belluz |first=Julia |date=January 27, 2019 |website=Vox}}</ref><ref>{{Cite web |url=https://www.newsweek.com/dangerous-anti-vaxx-warning-issued-washington-officials-cases-measles-1306997 |title="Dangerous" anti-vaxx warning issued by Washington officials as cases in measles outbreak continue to rise |date=January 28, 2019 |website=Newsweek}}</ref><ref>{{Cite web |url=https://www.cbsnews.com/news/measles-outbreak-public-health-emergency-declared-in-anti-vax-hotspot-near-portland-oregon-clark-county-washington/ |title=Public health emergency declared over measles in anti-vax hotspot near Portland, Oregon |website=Cbsnews.com |date=January 23, 2019 |access-date=February 5, 2019}}</ref>

===Wales, measles (2013–)===

In 2013, an outbreak of measles occurred in the Welsh city of Swansea. One death was reported.<ref name=over/> Some estimates indicate that while MMR uptake for two-year-olds was at 94% in Wales in 1995, it had fallen to as low as 67.5% in Swansea by 2003, meaning the region had a "vulnerable" age group.<ref>{{Cite news |url=https://www.bbc.com/news/uk-wales-politics-23244628 |title=Swansea measles epidemic: Worries over MMR uptake after outbreak |date=July 10, 2013 |work=BBC News |access-date=October 8, 2014}}</ref> This has been linked to the [[Social:MMR vaccine controversy|MMR vaccine controversy]], which caused a significant number of parents to fear allowing their children to receive the MMR vaccine.<ref name="over">{{Cite news |url=https://www.bbc.com/news/uk-wales-23168519 |title=Swansea measles epidemic officially over |date=July 3, 2013 |work=BBC News |access-date=October 8, 2014 |quote=Large numbers of children in the 10–18 age group were not given the MMR vaccine as babies, the result of a scare that caused panic among parents. It followed research by Dr. Andrew Wakefield in the late 1990s that linked the vaccine with autism and bowel disease. His report, which was published in The Lancet medical journal, was [[Unsolved:Lancet MMR autism fraud|later discredited]], with health officials insisting the vaccine was completely safe.}}</ref> June 5, 2017, saw a new measles outbreak in Wales, at Lliswerry High School in the town of Newport.<ref>{{Cite news |url=https://www.bbc.co.uk/news/uk-wales-south-east-wales-40366937 |title=600 children get MMR jab after measles outbreak in Newport |date=22 June 2017 |work=BBC News |publisher=BBC}}</ref>

===United States, tetanus===
Most cases of pediatric [[Medicine:Tetanus|tetanus]] in the U.S. occur in unvaccinated children.<ref>{{Cite journal |vauthors=Fair E, Murphy TV, Golaz A, Wharton M |date=January 2002 |title=Philosophic objection to vaccination as a risk for tetanus among children younger than 15 years |journal=Pediatrics |volume=109 |issue=1 |pages=E2 |doi=10.1542/peds.109.1.e2 |pmid=11773570|doi-access=}}</ref> In Oregon, in 2017, an unvaccinated boy had a scalp wound that his parents sutured themselves. Later the boy arrived at a hospital with tetanus. He spent 47 days in the Intensive Care Unit (ICU), and 57 total days in the hospital, for $811,929, not including the cost of airlifting him to the Oregon Health and Science University, Doernbecher Children's Hospital, or the subsequent two-and-a-half weeks of inpatient rehabilitation he required. Despite this, his parents declined the administration of subsequent tetanus boosters or other vaccinations.<ref>[https://www.washingtonpost.com/health/2019/03/08/an-unvaccinated-child-contracted-tetanus-it-took-two-months-more-than-k-save-him/ An unvaccinated child contracted tetanus. It took two months and more than $800K to save him.], ''Washington Post'', Amy Wang, March 8, 2019. Retrieved March 10, 2019.</ref>

===Romania, measles (2016–present)===
[[File:Ovidiu Covaciu ESC2017.webm|thumb|Ovidiu Covaciu on how the Romanian antivaccine movement threatens Europe (2017)]]

As of September 2017, a measles epidemic was ongoing across Europe, especially Eastern Europe. In Romania, there were about 9300 cases, and 34 people (all unvaccinated) had died.<ref name="Covaciu">{{Cite web |url=https://www.youtube.com/watch?v=wFpAiHCQ85g | archive-url=https://ghostarchive.org/varchive/youtube/20211030/wFpAiHCQ85g| archive-date=2021-10-30|title=How the Romanian anti-vaccine movement threatens Europe |last=Ovidiu Covaciu |date=5 November 2017 |website=European Skeptics Congress |publisher=European Council of Skeptical Organisations |access-date=6 November 2017}}{{cbignore}}</ref> This was preceded by a 2008 controversy regarding the HPV vaccine. In 2012, doctor Christa Todea-Gross published a free downloadable book online, this book contained misinformation about vaccination from abroad translated into Romanian, which significantly stimulated the growth of the anti-vaccine movement.<ref name="Covaciu" /> The government of Romania officially declared a measles epidemic in September 2016 and started an information campaign to encourage parents to have their children vaccinated. By February 2017, however, the stockpile of MMR vaccines was depleted, and doctors were overburdened. Around April, the vaccine stockpile had been restored. By March 2019, the death toll had risen to 62, with 15,981 cases reported.<ref>{{Cite web |url=http://www.cnscbt.ro/index.php/informari-saptamanale/rujeola-1/1143-situatia-rujeolei-in-romania-la-data-de-01-03-2019 |title=Centrul Național de Supraveghere şi Control al Bolilor Transmisibile – Informări săptămanale |website=cnscbt.ro |access-date=2019-03-07}}</ref>

===Samoa, measles (2019)===
The 2019 Samoa measles outbreak began in October 2019 and as of December 12, there were 4,995 confirmed cases of measles and 72 deaths, out of a Samoan population of 201,316.<ref>{{Cite web |url=https://www.cia.gov/the-world-factbook/countries/samoa/ |title=Australia – Oceania :: Samoa – The World Factbook |website=cia.gov – Central Intelligence Agency (July 2018 est.)|access-date=2019-12-06}}</ref><ref name="DeathToll">{{cite web |title=Measles death toll rises to 68 in Samoa |url=https://www.rnz.co.nz/international/pacific-news/405090/measles-death-toll-rises-to-68-in-samoa |website=RNZ|access-date=8 December 2019 |date=2019-12-08}}</ref><ref>{{Cite web |url=https://twitter.com/samoagovt/status/1202707973048418304 |title=Latest update: 4,357 measles cases have been reported since the outbreak with 140 recorded in the last 24 hours. mainly children under four years old.}}</ref><ref>{{Cite news |url=https://www.abc.net.au/news/2019-11-26/samoa-measles-emergency-claims-32-lives-as-death-toll-rises/11738138 |title=Samoa makes measles vaccinations compulsory after outbreak kills 32 |last=Beat |first=Pacific |date=2019-11-26 |website=ABC News |language=en-AU |access-date=2019-11-26}}</ref> A state of emergency was declared on November 17, ordering all schools to be closed, barring children under 17 from public events, and making vaccination mandatory.<ref>{{Cite news |url=https://www.abc.net.au/news/2019-11-17/samoa-declares-state-of-emergency-over-measles-outbreak/11711576 |title=Samoa declares state of emergency over deadly measles outbreak |date=2019-11-17 |newspaper=ABC News |language=en |access-date=2019-11-26}}</ref> UNICEF has sent 110,500 vaccines to Samoa. Tonga and Fiji have also declared states of emergency.<ref name="bbc">{{Cite news |url=https://www.bbc.com/news/world-asia-50528834 |title=Samoa measles outbreak worsens |date=2019-11-23 |access-date=2019-11-26 |language=en-GB}}</ref>

The outbreak has been attributed to a sharp drop in measles vaccination from the previous year, following an incident in 2018 when two infants died shortly after receiving measles vaccinations, which led the country to suspend its measles vaccination program.<ref name="TheGuardian">{{cite news |title=Samoa measles outbreak: WHO blames anti-vaccine scare as death toll hits 39 |url=https://www.theguardian.com/world/2019/nov/28/samoa-measles-outbreak-who-blames-anti-vaccine-scare-death-toll |newspaper=The Guardian |access-date=30 November 2019 |date=2019-11-28 |agency=Agence France-Presse}}</ref> The reason for the two infants' deaths was incorrect preparation of the vaccine by two nurses who mixed vaccine powder with expired anesthetic.<ref name="nurse"/> As of November 30, more than 50,000 people were vaccinated by the government of Samoa.<ref name="nurse">{{Cite news |url=https://www.abc.net.au/news/2019-08-02/samoa-nurses-sentenced-manslaughter-infant-vaccination-deaths/11378494 |title='Her body was turning black': Samoan nurses jailed for infant vaccination deaths |last=Beat |first=Pacific |date=2019-08-02 |website=ABC News |language=en-AU|access-date=2019-11-29}}</ref>

===2019–2020 measles outbreaks===

==Countermeasures==

Vaccine hesitancy is challenging and optimal strategies for approaching it remain uncertain.<ref name="Dubé2015">{{Cite journal |last1=Dubé |first1=E |last2=Gagnon |first2=D |last3=MacDonald |first3=NE |last4=SAGE Working Group on Vaccine Hesitancy. |date=August 2015 |title=Strategies intended to address vaccine hesitancy: Review of published reviews |journal=Vaccine |type=Review |volume=33 |issue=34 |pages=4191–4203 |doi=10.1016/j.vaccine.2015.04.041 |pmid=25896385|doi-access=free}}</ref><ref name="Dubé"/>

Multicomponent initiatives which include targeting undervaccinated populations, improving the convenience of and access to vaccines, educational initiatives, and mandates may improve vaccination uptake.<ref name="Brelsford2017" /><ref name="Jarrett2015">{{Cite journal |last1=Jarrett |first1=C |last2=Wilson |first2=R |last3=O'Leary |first3=M |last4=Eckersberger |first4=E |last5=Larson |first5=HJ |last6=SAGE Working Group on Vaccine Hesitancy. |date=August 2015 |title=Strategies for addressing vaccine hesitancy – A systematic review |url=https://zenodo.org/record/1009492 |journal=Vaccine |volume=33 |issue=34 |pages=4180–90 |doi=10.1016/j.vaccine.2015.04.040 |pmid=25896377|doi-access=free}}</ref>

The World Health Organization (WHO) published a paper in 2016 intending to aid experts on how to respond to vaccine deniers in public. The WHO recommends for experts to view the general public as their target audience rather than the vaccine denier when debating in a public forum. The WHO also suggests for experts to make unmasking the techniques that the vaccine denier uses to spread misinformation as the goal of the conversation. The WHO asserts that this will make the public audience more resilient against anti-vaccine tactics.<ref>{{cite web|title=How to respond to vocal vaccine deniers in public|publisher=World Health Organization|year=2016|url=https://www.who.int/immunization/sage/meetings/2016/october/8_Best-practice-guidance-respond-vocal-vaccine-deniers-public.pdf}}</ref>

===Providing information===
Many interventions designed to address vaccine hesitancy have been based on the [[Social:Information deficit model|information deficit model]].<ref name="McClure2017" /> This model assumes that vaccine hesitancy is due to a person lacking the necessary information and attempts to provide them with that information to solve the problem.<ref name="McClure2017" /> Despite many educational interventions attempting this approach, ample evidence indicates providing more information is often ineffective in changing a vaccine-hesitant person's views and may, in fact, have the opposite of the intended effect and reinforce their misconceptions.<ref name="Jacobson2020"/><ref name="McClure2017" />

It is unclear whether interventions intended to educate parents about vaccines improve the rate of vaccination.<ref name="Brelsford2017">{{Cite journal |last1=Brelsford |first1=D |last2=Knutzen |first2=E |last3=Neher |first3=JO |last4=Safranek |first4=S |date=December 2017 |title=Clinical Inquiries: Which interventions are effective in managing parental vaccine refusal? |url=https://mdedge-files-live.s3.us-east-2.amazonaws.com/files/s3fs-public/Document/November-2017/JFP06612e12.PDF |journal=Journal of Family Practice |volume=66 |issue=12 |pages=E12-14 |pmid=29202149 |access-date=June 8, 2019 |archive-date=June 8, 2019 |archive-url=https://web.archive.org/web/20190608003118/https://mdedge-files-live.s3.us-east-2.amazonaws.com/files/s3fs-public/Document/November-2017/JFP06612e12.PDF |url-status=dead }}</ref> It is also unclear whether citing the reasons of benefit to others and [[Medicine:Herd immunity|herd immunity]] improves parents' willingness to vaccinate their children.<ref name="Brelsford2017" /> In one trial, an educational intervention designed to dispel common misconceptions about the [[Medicine:Influenza vaccine|influenza vaccine]] decreased parents' false beliefs about the vaccines but did not improve uptake of the influenza vaccine.<ref name="Brelsford2017" /> In fact, parents with significant concerns about adverse effects from the vaccine were less likely to vaccinate their children with the influenza vaccine after receiving this education.<ref name="Brelsford2017" />

===Communication strategies===
Several communication strategies are recommended for use when interacting with vaccine-hesitant parents. These include establishing honest and respectful dialogue; acknowledging the risks of a vaccine but balancing them against the risk of disease; referring parents to reputable sources of vaccine information; and maintaining ongoing conversations with vaccine-hesitant families.<ref name="Smith2015" /> The American Academy of Pediatrics recommends healthcare providers directly address parental concerns about vaccines when questioned about their efficacy and safety.<ref name="Edwards2016" /> Additional recommendations include asking permission to share information; maintaining a conversational tone (as opposed to lecturing); not spending excessive amounts of time debunking specific myths (this may have the opposite effect of strengthening the myth in the person's mind); focusing on the facts and simply identifying the myth as false; and keeping information as simple as possible (if the myth seems simpler than the truth, it may be easier for people to accept the simple myth).<ref name="McClure2017" /> Storytelling and anecdote (e.g., about the decision to vaccinate one's own children) can be powerful communication tools for conversations about the value of vaccination.<ref name="McClure2017" /> A New Zealand-based General Practitioner has used a comic, ''Jenny & the Eddies'', both to educate children about vaccines and address his patients' concerns through open, trusting, and non-threatening conversations, concluding [that] "I always listen to what people have to say on any matter. That includes vaccine hesitancy. That's a very important opening stage to improving the therapeutic relationship. If I'm going to change anyone's attitude, first I need to listen to them and be open-minded."<ref name="Using books to help in NZ">{{cite news |last1=McKenzie |first1=Peter |title=Covid-19: Doctor using comics to confront vaccine conspiracy theories |url=https://www.stuff.co.nz/national/health/300212725/covid19-doctor-using-comics-to-confront-vaccine-conspiracy-theories |access-date=23 March 2021 |publisher=Stuff (New Zealand) |date=24 January 2021}}</ref> The perceived strength of the recommendation, when provided by a healthcare provider, also seems to influence uptake, with recommendations that are perceived to be stronger resulting in higher vaccination rates than perceived weaker recommendations.<ref name="Jacobson2020"/>

===Provider presumption and persistence===
Limited evidence suggests that a more paternalistic or presumptive approach ("Your son needs three shots today.") is more likely to result in patient acceptance of vaccines during a clinic visit than a participatory approach ("What do you want to do about shots?") but decreases patient satisfaction with the visit.<ref name="Brelsford2017" /> A presumptive approach helps to establish that this is the normative choice.<ref name="McClure2017">{{Cite journal |last1=McClure |first1=CC |last2=Cataldi |first2=JR |last3=O'Leary |first3=ST |date=August 2017 |title=Vaccine Hesitancy: Where We Are and Where We Are Going |journal=Clinical Therapeutics |volume=39 |issue=8 |pages=1550–62 |doi=10.1016/j.clinthera.2017.07.003 |pmid=28774498|doi-access=free}}</ref> Similarly, one study found that the way in which physicians respond to parental vaccine resistance is important.<ref name="Smith2015" /> Nearly half of initially vaccine-resistant parents accepted vaccinations if physicians persisted in their initial recommendation.<ref name="McClure2017" /> The Centers for Disease Control and Prevention has released resources to aid healthcare providers in having more effective conversations with parents about vaccinations.<ref name="CDCVaccineConversationResources">{{Cite web |url=https://www.cdc.gov/vaccines/hcp/conversations/index.html |title=Provider Resources for Vaccine Conversations with Parents |date=May 28, 2019 |website=cdc.gov |publisher=Centers for Disease Control and Prevention}}</ref>

===Pain mitigation for children===
Parents may be hesitant to have their children vaccinated due to concerns about the pain of vaccination. Several strategies can be used to reduce the child's pain.<ref name="Edwards2016" /> Such strategies include distraction techniques (pinwheels); deep breathing techniques; [[Social:Breastfeeding|breastfeeding]] the child; giving the child sweet-tasting solutions; quickly administering the vaccine without aspirating; keeping the child upright; providing tactile stimulation; applying numbing agents to the skin; and saving the most painful vaccine for last.<ref name="Edwards2016" /> As above, the number of vaccines offered in a particular encounter is related to the likelihood of parental vaccine refusal (the more vaccines offered, the higher the likelihood of vaccine deferral).<ref name="Smith2015" /> The use of combination vaccines to protect against more diseases but with fewer injections may provide reassurance to parents.<ref name="Smith2015" /> Similarly, reframing the conversation with less emphasis on the number of diseases the healthcare provider is immunizing against (e.g., "we will do two injections (combined vaccinations) and an oral vaccine") may be more acceptable to parents than "we're going to vaccinate against seven diseases".<ref name="Smith2015" />

===Cultural sensitivity===

Cultural sensitivity is important to reducing vaccine hesitancy. For example, pollster [[Biography:Frank Luntz|Frank Luntz]] discovered that for conservative Americans, family is by far the "most powerful motivator" to get a vaccine (over country, economy, community, or friends).<ref name="Kenen">{{cite news |last1=Kenen |first1=Joanne |title=Vaccine-skeptical Trump country poses challenge to immunization push |url=https://www.politico.com/news/2021/03/08/coronavirus-vaccine-rural-america-473940 |work=Politico |date=March 8, 2021}}</ref> Luntz "also found a very pronounced preference for the word 'vaccine' over 'jab.{{' "}}<ref name="Kenen" />

===Avoiding online misinformation===
It is recommended that healthcare providers advise parents against performing their own web search queries since many websites on the Internet contain significant misinformation.<ref name="Smith2015" /> Many parents perform their own research online and are often confused, frustrated, and unsure of which sources of information are trustworthy.<ref name="McClure2017" /> Additional recommendations include introducing parents to the importance of vaccination as far in advance of the initial well-child visit as possible; presenting parents with vaccine safety information while in their pediatrician's waiting room; and using prenatal open houses and postpartum maternity ward visits as opportunities to vaccinate.<ref name="Smith2015" />

Internet advertising, especially on social networking websites, is purchased by both public health authorities and anti-vaccination groups. In the United States, the majority of anti-vaccine Facebook advertising in December 2018 and February 2019 had been paid for one of two groups: [[Organization:Children's Health Defense|Children's Health Defense]] and [[Unsolved:Stop Mandatory Vaccination|Stop Mandatory Vaccination]]. The ads targeted women and young couples and generally highlighted the alleged risks of vaccines, while asking for donations. Several anti-vaccination advertising campaigns also targeted areas where measles outbreaks were underway during this period. The impact of Facebook's subsequent advertising policy changes has not been studied.<ref name="journ">{{Cite journal |last1=Jamison |first1=A.M. |last2=Broniatowski |first2=D. A. |last3=Dredze |first3=M. |date=2019-11-13 |title=Vaccine-related advertising in the Facebook Ad Archive |url= |journal=Vaccine |volume=38 |issue=3 |pages=512–20 |doi=10.1016/j.vaccine.2019.10.066 |pmid=31732327 |pmc=6954281}}</ref><ref name="study">{{Cite news |url=https://www.washingtonpost.com/health/2019/11/15/majority-anti-vaccine-ads-facebook-were-funded-by-two-groups/ |title=Majority of anti-vaccine ads on Facebook were funded by two groups |last=Sun |first=Lena H. |date=2019-11-15 |newspaper=The Washington Post |access-date=2019-11-16 |url-status=live |archive-url=https://web.archive.org/web/20191117003403/https://www.washingtonpost.com/health/2019/11/15/majority-anti-vaccine-ads-facebook-were-funded-by-two-groups/ |archive-date=2019-11-17}}</ref>

=== Incentive programs ===
Several countries have implemented programs to counter vaccine hesitancy, including raffles, lotteries, rewards and mandates.<ref>{{cite news|url=https://www.economist.com/asia/2021/06/12/politicians-in-the-philippines-are-holding-raffles-to-boost-vaccination | title=Politicians in the Philippines are holding raffles to boost vaccination | newspaper=The Economist | date=12 June 2021}}</ref><ref>{{cite web|url=https://www.aljazeera.com/news/2021/6/14/win-a-cow-avoid-covid-philippines-tempts-vaccine-hesitant | title=Win a cow, avoid COVID: Philippines tempts vaccine hesitant | website= Al Jazeera | date=14 June 2021}}</ref><ref>{{cite web|url=https://www.scientificamerican.com/article/from-1-million-lotteries-to-free-beer-do-covid-vaccination-incentives-work/ | title=From $1-Million Lotteries to Free Beer: Do COVID Vaccination Incentives Work? | website=Scientific American |date=June 17, 2021 | author=Tanya Lewis }}</ref><ref>{{cite web|url=https://abcnews.go.com/Health/wireStory/jab-win-condo-hong-kong-vaccine-incentives-78330532 | title=Get a jab, win a condo: Hong Kong tries vaccine incentives | website=ABC News | date=17 June 2021 | author=ZEN SOO}}</ref> In the US State of Washington, authorities have given the green light to licensed cannabis dispensaries to offer free joints as incentives to get COVID-19 vaccination in an effort dubbed "Joints for Jabs".<ref>{{cite news|url=https://www.telegraph.co.uk/global-health/science-and-disease/joints-jabs-washington-state-allows-free-cannabis-covid-19-vaccination/ |archive-url=https://ghostarchive.org/archive/20220111/https://www.telegraph.co.uk/global-health/science-and-disease/joints-jabs-washington-state-allows-free-cannabis-covid-19-vaccination/ |archive-date=January 11, 2022 |url-access=subscription |url-status=live | title='Joints for jabs': US state offers free cannabis as vaccine incentive | website=The Telegraph | date=8 June 2021  | author=Ben Farmer}}{{cbignore}}</ref>

=== Vaccine mandates ===
Mandatory vaccination is one set of policy measures to address vaccine hesitancy by imposing penalties or burdens on those who fail to vaccinate. An example of this kind of measure is Australia's vaccine mandates around childhood vaccination, the No Jab No Pay policy. This policy linked financial payments to children's vaccine status and, while studies have found significant improvements in vaccination compliance, years later there were still issues of vaccine hesitancy.<ref>{{cite journal |last1=Hull |first1=Brynley P |last2=Beard |first2=Frank H |last3=Hendry |first3=Alexandra J |last4=Dey |first4=Aditi |last5=Macartney |first5=Kristine |title="No jab, no pay": catch-up vaccination activity during its first two years |journal=Med J Aust |date=2020 |volume=213 |issue=8 |pages=364–369 |doi=10.5694/mja2.50780|pmid=32951230 |pmc=7692886 |doi-access=free }}</ref><ref>{{cite journal |last1=Li |first1=Ang. |last2=Toll |first2=Mathew. |title=Removing conscientious objection: The impact of 'No Jab No Pay' and 'No Jab No Play' vaccine policies in Australia |journal=Preventive Medicine |date=2020 |volume=145 |page=106406 |doi=10.1016/j.ypmed.2020.106406 |pmid=33388333 |s2cid=230489130 |url=https://www.sciencedirect.com/science/article/abs/pii/S0091743520304370}}</ref> In 2021, Australian airline [[Company:Qantas|Qantas]] issued plans to mandate COVID-19 vaccination for their work force.<ref>{{cite news |last1=Williams |first1=Jane |last2=Seale |first2=Holly |title=If you're going to mandate COVID vaccination at your workplace, here's how to do it ethically |url=https://theconversation.com/if-youre-going-to-mandate-covid-vaccination-at-your-workplace-heres-how-to-do-it-ethically-166110 |agency=The Conversation |date=August 18, 2021}}</ref>

==History==
===Variolation===
[[File:The cow pock.jpg|thumb |upright=1.25 |An anti-vaccination caricature by James Gillray, ''The Cow-Pock{{snd}}or{{snd}}The Wonderful Effects of the New Inoculation!'' (1802)]]

Early attempts to prevent smallpox involved deliberate [[Biology:Inoculation|inoculation]] with the milder form of the disease (Variola Minor) in the expectation that a mild case would confer immunity and avoid Variola Major. Originally called inoculation, this technique was later called [[Biology:Variolation|variolation]] to avoid confusion with cowpox inoculation ([[Biology:Vaccination|vaccination]]) when that was introduced by Edward Jenner. Although variolation had a long history in China and India, it was first used in North America and England in 1721. [[Biography:Cotton Mather|Reverend Cotton Mather]] introduced variolation to Boston, Massachusetts, during the 1721 smallpox epidemic.<ref name="VaccineControversy">{{Cite book |url=https://archive.org/details/vaccinecontrover00arth |title=Vaccine: The Controversial Story of Medicine's Greatest Lifesaver |last=Allen |first=Arthur |publisher=W. W. Norton & Company, Inc. |year=2007 |isbn=978-0-393-05911-3 |location=New York |pages=25–36 |name-list-style=vanc}}</ref> Despite strong opposition in the community,<ref name="Early" /> Mather convinced Zabdiel Boylston to try it. Boylston first experimented on his 6-year-old son, his slave, and his slave's son; each subject contracted the disease and was sick for several days until the sickness vanished<!--Is "miraculously vanished" a direct quote?--> and they were "no longer gravely ill".<ref name="VaccineControversy" /> Boylston went on to variolate thousands of Massachusetts residents, and many places were named for him in gratitude as a result. [[Biography:Lady Mary Wortley Montagu|Lady Mary Wortley Montagu]] introduced variolation to England. She had seen it used in Turkey and, in 1718, had her son successfully variolated in Constantinople under the supervision of Charles Maitland. When she returned to England in 1721, she had her daughter variolated by Maitland. This aroused considerable interest, and Sir Hans Sloane organized the variolation of some inmates in Newgate Prison. These were successful, and after a further short trial in 1722, two daughters of Caroline of Ansbach Princess of Wales were variolated without mishap. With this royal approval, the procedure became common when smallpox epidemics threatened.<ref name="williams">{{Cite book |title=Angel Of Death; the story of smallpox |last=Williams |first=Gareth |publisher=Palgrave Macmillan |year=2010 |isbn=978-0-230-27471-6 |location=Basingstoke, UK |pages=87–94 |name-list-style=vanc}}</ref>

[[Medicine:Vaccination and religion|Religious arguments against inoculation]] were soon advanced. For example, in a 1722 sermon entitled "The Dangerous and Sinful Practice of Inoculation", the English theologian Reverend Edmund Massey argued that diseases are sent by God to punish sin and that any attempt to prevent smallpox via inoculation is a "diabolical operation".<ref name="Early" /> It was customary at the time for popular preachers to publish sermons, which reached a wide audience. This was the case with Massey, whose sermon reached North America, where there was early religious opposition, particularly by John Williams. A greater source of opposition there was William Douglass, a medical graduate of Edinburgh University and a Fellow of the Royal Society, who had settled in Boston.<ref name=williams/>{{rp |114–22}}

===Smallpox vaccination===
[[File:Edward Jenner2.jpg|thumb|Edward Jenner]]

After Edward Jenner introduced the [[Medicine:Smallpox vaccine|smallpox vaccine]] in 1798, variolation declined and was banned in some countries.<ref>{{Cite journal |vauthors=Bazin H |date=October 2003 |title=A brief history of the prevention of infectious diseases by immunisations |journal=Comparative Immunology, Microbiology and Infectious Diseases |volume=26 |issue=5–6 |pages=293–308 |doi=10.1016/S0147-9571(03)00016-X |pmid=12818618}}</ref><ref>{{Cite journal |vauthors=Ellner PD |year=1998 |title=Smallpox: gone but not forgotten |journal=Infection |volume=26 |issue=5 |pages=263–69 |doi=10.1007/BF02962244 |pmid=9795781 |s2cid=23658644|doi-access=free }}</ref> As with variolation, there was some religious opposition to vaccination, although this was balanced to some extent by support from clergymen, such as Reverend Robert Ferryman, a friend of Jenner's, and [[Biography:Rowland Hill (preacher)|Rowland Hill]],<ref name=williams/>{{rp |221}} who not only preached in its favour but also performed vaccination themselves. There was also opposition from some variolators who saw the loss of a lucrative monopoly. William Rowley published illustrations of deformities allegedly produced by vaccination, lampooned in James Gillray's famous caricature depicted on this page, and Benjamin Moseley likened cowpox to [[Medicine:Syphilis|syphilis]], starting a controversy that would last into the 20th century.<ref name=williams/>{{rp |203–05}}
[[File:Gloucester smallpox epidemic, 1896; Henry Wicklin, aged 6 Wellcome V0031456.jpg|thumb|Henry Wicklin, age 6, affected by smallpox. Smallpox was eradicated worldwide as a result of mandatory vaccinations.]]
There was legitimate concern from supporters of vaccination about its safety and efficacy, but this was overshadowed by general condemnation, particularly when legislation started to introduce compulsory vaccination. The reason for this was that vaccination was introduced before laboratory methods were developed to control its production and account for its failures.<ref name="baxby2001">{{Cite book |title=Smallpox Vaccine, Ahead of its Time |last=Baxby |first=Derrick|publisher=the Jenner Museum |year=2001 |isbn=0-9528695-1-9 |location=Berkeley, UK |pages=12–21 |name-list-style=vanc}}</ref> Vaccine was maintained initially through arm-to-arm transfer and later through production on the skin of animals, and bacteriological sterility was impossible. Further, identification methods for potential pathogens were not available until the late 19th to early 20th century. Diseases later shown to be caused by contaminated vaccine included [[Medicine:Erysipelas|erysipelas]], [[Medicine:Tuberculosis|tuberculosis]], [[Medicine:Tetanus|tetanus]], and syphilis. This last, though rare{{snd}}estimated at 750 cases in 100 million vaccinations<ref name="bazin2000">{{Cite book |title=The Eradication of Smallpox |last=Bazin |first=Hervé |publisher=Academic Press |year=2000 |isbn=0-12-083475-8 |location=London |page=122 |name-list-style=vanc}}</ref>{{snd}}attracted particular attention. Much later, Charles Creighton, a leading medical opponent of vaccination, claimed that the vaccine itself was a cause of syphilis and devoted a book to the subject.<ref name="creighton">{{Cite book |title=The Natural History of Cowpox and Vaccinal Syphilis |last=Creighton |first=Charles |publisher=Cassell |year=1887 |location=London |name-list-style=vanc}}</ref> As cases of smallpox started to occur in those who had been vaccinated earlier, supporters of vaccination pointed out that these were usually very mild and occurred years after the vaccination. In turn, opponents of vaccination pointed out that this contradicted Jenner's belief that vaccination conferred complete protection.<ref name=baxby2001/>{{rp |17–21}} The views of opponents of vaccination that it was both dangerous and ineffective led to the development of determined anti-vaccination movements in England when legislation was introduced to make vaccination compulsory.<ref name="williamson">{{Cite book |title=The Vaccination Controversy; the rise, reign and decline of compulsory vaccination |last=Williamson |first=Stanley |publisher=Liverpool University Press |year=2007 |isbn=978-1846310867 |location=Liverpool |name-list-style=vanc}}</ref>

====England====
[[File:Diphtheria is Deadly Art.IWMPST14182.jpg|thumb |upright |In a postwar poster the Ministry of Health urged British residents to immunize children against diphtheria.]]

Because of its greater risks, [[Biology:Variolation|variolation]] was banned in England by the 1840 [[Biology:Vaccination Act|Vaccination Act]], which also introduced free voluntary vaccination for infants. Thereafter Parliament passed successive acts to enact and enforce compulsory vaccination.<ref name="porter">{{Cite journal |vauthors=Porter D, Porter R |date=July 1988 |title=The politics of prevention: anti-vaccinationism and public health in nineteenth-century England |journal=Medical History |volume=32 |issue=3 |pages=231–52 |doi=10.1017/s0025727300048225 |pmc=1139881 |pmid=3063903}}</ref> The 1853 act introduced compulsory vaccination, with fines for non-compliance and imprisonment for non-payment. The 1867 act extended the age requirement to 14 years and introduced repeated fines for repeated refusal for the same child. Initially, vaccination regulations were organised by the local Poor Law Guardians, and in towns where there was strong opposition to vaccination, sympathetic Guardians were elected who did not pursue prosecutions. This was changed by the 1871 act, which required Guardians to act. This significantly changed the relationship between the government and the public, and organized protests increased.<ref name=porter/> In Keighley, Yorkshire, in 1876 the Guardians were arrested and briefly imprisoned in York Castle, prompting large demonstrations in support of the "Keighley Seven".<ref name=williamson/>{{rp |108–09}} The protest movements crossed social boundaries. The financial burden of fines fell hardest on the working class, who would provide the largest numbers at public demonstrations.<ref>{{Cite journal |vauthors=Durbach N |date=April 2000 |title='They might as well brand us': working-class resistance to compulsory vaccination in Victorian England |journal=Social History of Medicine |volume=13 |issue=1 |pages=45–62 |doi=10.1093/shm/13.1.45 |pmid=11624425}}</ref> Societies and publications were organized by the middle classes, and support came from celebrities such as [[Biography:George Bernard Shaw|George Bernard Shaw]] and [[Biography:Alfred Russel Wallace|Alfred Russel Wallace]], doctors such as Charles Creighton and Edgar Crookshank, and parliamentarians such as Jacob Bright and James Allanson Picton.<ref name=porter/> By 1885, with over 3,000 prosecutions pending in Leicester, a mass rally there was attended by over 20,000 protesters.<ref name="baxby1999">{{Cite journal |last=Baxby |first=Derrick |year=1999 |title=The End of Smallpox |journal=History Today |volume=49 |issue=3 |pages=14–16 |pmid=21384695}}</ref>

Under increasing pressure, the government appointed a Royal Commission on Vaccination in 1889, which issued six reports between 1892 and 1896, with a detailed summary in 1898.<ref>{{Cite book |title=Vaccination and its Results; a Report based on the Evidence taken by the Royal Commission |last=(Royal Commission) |publisher=New Sydenham Society |year=1898 |location=London}}</ref> Its recommendations were incorporated into the 1898 Vaccination Act, which still required compulsory vaccination but allowed exemption on the grounds of conscientious objection on presentation of a certificate signed by two magistrates.<ref name="wolfesharp">{{Cite journal |vauthors=Wolfe RM, Sharp LK |date=August 2002 |title=Anti-vaccinationists past and present |journal=BMJ |volume=325 |issue=7361 |pages=430–32 |doi=10.1136/bmj.325.7361.430 |pmc=1123944 |pmid=12193361}}</ref><ref name="porter" /> These were not easy to obtain in towns where magistrates supported compulsory vaccination, and after continued protests, a further act in 1907 allowed exemption on a simple signed declaration.<ref name="baxby1999" /> Although this solved the immediate problem, the compulsory vaccination acts remained legally enforceable, and determined opponents lobbied for their repeal. No Compulsory Vaccination was one of the demands of the 1900 Labour Party General Election Manifesto.<ref>{{Cite web |url=https://suacs.wordpress.com/2014/04/20/labour-party-manifesto-1900/ |title=Labour Party Manifesto 1900 |date=2014-04-20 |website=Voice of Anti-Capitalism in Guildford |access-date=July 2, 2015}}</ref> This was done as a matter of routine when the National Health Service was introduced in 1948, with "almost negligible" opposition from supporters of compulsory vaccination.<ref name="millard1948">{{Cite journal |vauthors=Millard CK |date=December 1948 |title=The end of compulsory vaccination |journal=British Medical Journal |volume=2 |issue=4589 |pages=1073–75 |doi=10.1136/bmj.2.4589.1073 |pmc=2092290 |pmid=18121624}}</ref>

Vaccination in Wales was covered by English legislation, but the Scottish legal system was separate. Vaccination was not made compulsory there until 1863, and a conscientious objection was allowed after vigorous protest only in 1907.<ref name="baxby2001" />{{rp |10–11}}

In the late 19th century, Leicester in the UK received much attention because of how smallpox was managed there. There was particularly strong opposition to compulsory vaccination, and medical authorities had to work within this framework. They developed a system that did not use vaccination but was based on the notification of cases, the strict isolation of patients and contacts, and the provision of isolation hospitals.<ref>{{Cite book |url=http://www.urpress.com/store/viewItem.asp?idProduct=14810 |title=Intrusive Interventions: Public Health, Domestic Space, and Infectious Disease Surveillance in England, 1840–1914 |last=Mooney |first=Graham |date=2015 |publisher=University of Rochester Press |isbn=978-1580465274 |location=Rochester, NY |access-date=2 April 2016}}</ref> This proved successful but required acceptance of compulsory isolation rather than vaccination. C. Killick Millard, initially, a supporter of compulsory vaccination was appointed [[Medicine:Medical Officer of Health|Medical Officer of Health]] in 1901. He moderated his views on compulsion but encouraged contacts and his staff to accept vaccination. This approach, developed initially due to overwhelming opposition to government policy, became known as the Leicester Method.<ref name="millard1948" /><ref name="fraser">{{Cite journal |vauthors=Fraser SM |date=July 1980 |title=Leicester and smallpox: the Leicester method |journal=Medical History |volume=24 |issue=3 |pages=315–32 |doi=10.1017/s0025727300040345 |pmc=1082657 |pmid=6997656}}</ref> In time it became generally accepted as the most appropriate way to deal with smallpox outbreaks and was listed as one of the "important events in the history of smallpox control" by those most involved in the [[Organization:World Health Organization|World Health Organization]]'s successful [[Medicine:Smallpox|Smallpox]] Eradication Campaign. The final stages of the campaign generally referred to as "surveillance containment", owed much to the Leicester method.<ref>{{Cite book |title=Smallpox and its Eradication |vauthors=Fenner F, Henderson DA, Arita I, Jezek Z, Ladnyi ID |publisher=World Health Organization |year=1988 |isbn=978-9241561105 |location=Geneva |pages=247, 275}}</ref><ref>{{Cite book |title=Smallpox; the death of a disease |last=Henderson |first=Donald A. |publisher=Prometheus Books |year=2009 |isbn=978-1-59102-722-5 |location=Amherst, NY |pages=90–92 |name-list-style=vanc}}</ref>

====United States====
In the US, President Thomas Jefferson took a close interest in vaccination, alongside Benjamin Waterhouse, chief physician at Boston. Jefferson encouraged the development of ways to transport vaccine material through the Southern states, which included measures to avoid damage by heat, a leading cause of ineffective batches. [[Medicine:Smallpox|Smallpox]] outbreaks were contained by the latter half of the 19th century, a development widely attributed to the vaccination of a large portion of the population. Vaccination rates fell after this decline in smallpox cases, and the disease again became epidemic in the late 19th century.<ref>{{cite book |editor=Plotkin SA, Orenstein WA |title=Vaccines |vauthors=Henderson DA, Moss B |url=https://www.ncbi.nlm.nih.gov/books/NBK7291/ |chapter=Public health |chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK7293/ |edition=3rd |publisher=W. B. Saunders |location=Philadelphia |isbn=0-7216-7443-7 |date=1999}}</ref>

After an 1879 visit to New York by prominent British anti-vaccinationist William Tebb, The Anti-Vaccination Society of America was founded.<ref>{{Cite journal |vauthors=Wolfe RM, Sharp LK |date=August 2002 |title=Anti-vaccinationists past and present |journal=BMJ |volume=325 |issue=7361 |pages=430–32 |doi=10.1136/bmj.325.7361.430 |pmc=1123944 |pmid=12193361 |quote=In 1879, after a visit to New York by William Tebb, the leading British anti-vaccinationist, the Anti-Vaccination Society of America was founded. Subsequently, the New England Anti-Compulsory Vaccination League was formed in 1882 and the Anti-Vaccination League of New York City in 1885.}}</ref><ref name="history">{{Cite news |url=http://www.historyofvaccines.org/content/articles/history-anti-vaccination-movements |title=History of Anti-vaccination Movements |date=March 8, 2012 |access-date=2015-02-11 |publisher=College of Physicians of Philadelphia |quote=The Anti Vaccination Society of America was founded in 1879, following a visit to America by leading British anti-vaccinationist William Tebb. Two other leagues, the New England Anti Compulsory Vaccination League (1882) and the Anti-Vaccination League of New York City (1885) followed.{{spaces}}...}}</ref> The New England Anti-Compulsory Vaccination League formed in 1882, and the Anti-Vaccination League of New York City in 1885.<ref name=history/> Tactics in the US largely followed those used in England.<ref>{{Cite journal |vauthors=Kaufman M |year=1967 |title=The American anti-vaccinationists and their arguments |journal=Bulletin of the History of Medicine |volume=41 |issue=5 |pages=463–78 |pmid=4865041}}</ref> Vaccination in the US was regulated by individual states, in which there followed a progression of compulsion, opposition, and repeal similar to that in England.<ref>{{Cite book |url=https://archive.org/details/greatestkillersm0000hopk |title=The Greatest Killer; smallpox in history |last=Hopkins |first=Donald R. |publisher=University of Chicago Press |year=2002 |isbn=978-0226351667 |location=Chicago |pages=[https://archive.org/details/greatestkillersm0000hopk/page/83 83–84] |name-list-style=vanc |url-access=registration}}</ref> Although generally organized on a state-by-state basis, the vaccination controversy reached the US Supreme Court in 1905. There, in the case of ''[[Biology:Jacobson v. Massachusetts|Jacobson v. Massachusetts]]'', the court ruled that states have the authority to require vaccination against smallpox during a smallpox epidemic.<ref>{{Cite journal |vauthors=Mariner WK, Annas GJ, Glantz LH |date=April 2005 |title=Jacobson v Massachusetts: it's not your great-great-grandfather's public health law |journal=American Journal of Public Health |volume=95 |issue=4 |pages=581–90 |doi=10.2105/AJPH.2004.055160 |pmc=1449224 |pmid=15798113}}</ref>

John Pitcairn, the wealthy founder of the Pittsburgh Plate Glass Company (now [[Company:PPG Industries|PPG Industries]]), emerged as a major financier and leader of the American anti-vaccination movement. On March 5, 1907, in Harrisburg, Pennsylvania, he delivered an address to the Committee on Public Health and Sanitation of the Pennsylvania General Assembly criticizing vaccination.<ref name="vaccination_address">{{Cite book |url=https://archive.org/details/vaccination00pitcgoog |title=Vaccination |last=Pitcairn J |publisher=Anti-Vaccination League of Pennsylvania |year=1907 |oclc=454411147}}</ref> He later sponsored the National Anti-Vaccination Conference, which, held in Philadelphia in October 1908, led to the creation of The Anti-Vaccination League of America. When the league organized later that month, members chose Pitcairn as their first president.<ref name="Horrors">{{Cite book |title=Horrors of Vaccination Exposed and Illustrated |last=Higgins CM |publisher=C.M. Higgins |year=1920 |location=Brooklyn, NY |pages=73–75 |chapter=Life sketch of John Pitcairn by a Philadelphia friend |oclc=447437840 |chapter-url=https://archive.org/details/horrorsvaccinat00higggoog}}</ref>

On December 1, 1911, Pitcairn was appointed by Pennsylvania Governor John K. Tener to the Pennsylvania State Vaccination Commission and subsequently authored a detailed report strongly opposing the commission's conclusions.<ref name="Horrors" /> He remained a staunch opponent of vaccination until his death in 1916.

====Brazil====
In November 1904, in response to years of inadequate sanitation and disease, followed by a poorly explained public health campaign led by the renowned Brazilian public health official Oswaldo Cruz, citizens and military cadets in Rio de Janeiro arose in a ''Revolta da Vacina'', or [[Biology:Vaccine Revolt|Vaccine Revolt]]. Riots broke out on the day a vaccination law took effect; vaccination symbolized the most feared and most tangible aspect of a public health plan that included other features, such as urban renewal, that many had opposed for years.<ref>{{Cite journal |last=Meade T |year=1989 |title='Living worse and costing more': resistance and riot in Rio de Janeiro, 1890–1917 |journal=J Lat Am Stud |volume=21 |issue=2 |pages=241–66 |doi=10.1017/S0022216X00014784|s2cid=145241097 }}</ref>

===Later vaccines and antitoxins===
Opposition to smallpox vaccination continued into the 20th century and was joined by controversy over new vaccines and the introduction of [[Biology:Antitoxin|antitoxin]] treatment for [[Medicine:Diphtheria|diphtheria]]. Injection of horse serum into humans as used in antitoxin can cause [[Medicine:Hypersensitivity|hypersensitivity]], commonly referred to as serum sickness. Moreover, the continued production of the smallpox vaccine in animals and the production of antitoxins in horses prompted anti-vivisectionists to oppose vaccination.<ref>Ciok, Amy E. "Horses and the diphtheria antitoxin." ''Academic Medicine'' 75.4 (2000): 396.</ref>

Diphtheria antitoxin was serum from horses that had been immunized against diphtheria, and was used to treat human cases by providing [[Biology:Passive immunity|passive immunity]]. In 1901, antitoxin from a horse named [[Medicine:Jim (horse)|Jim]] was contaminated with [[Medicine:Tetanus|tetanus]] and killed 13 children in St. Louis, Missouri. This incident, together with nine deaths from tetanus from contaminated smallpox vaccine in Camden, New Jersey, led directly and quickly to the passing of the [[Medicine:Biologics Control Act|Biologics Control Act]] in 1902.<ref>{{Cite journal |vauthors=Lilienfeld DE |year=2008 |title=The first pharmacoepidemiologic investigations: national drug safety policy in the United States, 1901–1902 |journal=Perspectives in Biology and Medicine |volume=51 |issue=2 |pages=188–98 |doi=10.1353/pbm.0.0010 |pmid=18453724 |s2cid=30767303}}</ref> The Bundaberg tragedy of 1928 saw a diphtheria antitoxin contaminated with the ''Staph. aureus'' bacterium kill 12 children in Bundaberg, Australia, resulting in the suspension of local immunisation programs.<ref>{{cite journal|title=Bundaberg's Gethsemane: the tragedy of the inoculated children|first1=Harry|last1=Akers|first2=Suzette|last2=Porter|journal=Royal Historical Society of Queensland Journal|volume=20|number=7|year=2008|pages=261–278|url=https://espace.library.uq.edu.au/view/UQ:152716/UQ_PV_152716.pdf}}</ref>

[[Biography:Robert Koch|Robert Koch]] developed [[Chemistry:Tuberculin|tuberculin]] in 1890. Inoculated into individuals who have had [[Medicine:Tuberculosis|tuberculosis]], it produces a [[Medicine:Hypersensitivity|hypersensitivity]] reaction and is still used to detect those who have been infected. However, Koch used tuberculin as a vaccine. This caused serious reactions and deaths in individuals whose latent tuberculosis was reactivated by the tuberculin.<ref>{{Cite book |title=Laboratory Disease; Robert Koch's medical bacteriology |last=Gradman |first=Christopher |publisher=Johns Hopkins University Press |year=2009 |isbn=978-0-8018-9313-1 |location=Baltimore |pages=133–36 |name-list-style=vanc}}</ref> This was a major setback for supporters of new vaccines.<ref name=baxby2001/>{{rp |30–31}} Such incidents and others ensured that any untoward results concerning vaccination and related procedures received continued publicity, which grew as the number of new procedures increased.<ref>Brock, Thomas. ''Robert Koch: A life in medicine and bacteriology''. ASM Press: Washington DC, 1999. Print.</ref>

In 1955, in a tragedy known as the [[Biology:Cutter incident|Cutter incident]], [[Organization:Cutter Laboratories|Cutter Laboratories]] produced 120,000 doses of the Salk polio vaccine that inadvertently contained some live poliovirus along with inactivated virus. This vaccine caused 40,000 cases of polio, 53 cases of paralysis, and five deaths. The disease spread through the recipients' families, creating a polio epidemic that led to a further 113 cases of paralytic polio and another five deaths. It was one of the worst pharmaceutical disasters in US history.<ref>{{Cite journal |vauthors=Offit PA |date=April 2005 |title=The Cutter incident, 50 years later |journal=The New England Journal of Medicine |volume=352 |issue=14 |pages=1411–12 |doi=10.1056/NEJMp048180 |pmid=15814877}}</ref>

Later 20th-century events included the 1982 broadcast of ''DPT: Vaccine Roulette'', which sparked debate over the [[Medicine:DPT vaccine|DPT vaccine]],<ref>{{Cite news |url=https://www.npr.org/templates/story/story.php?storyId=123472234 |title=Scientist: autism paper had catastrophic effects |date=2010-02-07 |publisher=NPR}}</ref> and the 1998 publication of a fraudulent academic article by [[Biography:Andrew Wakefield|Andrew Wakefield]]<ref name="Goldacre-2008">{{Cite news |url=https://www.theguardian.com/society/2008/aug/30/mmr.health.media |title=The MMR hoax |last=Goldacre B |date=August 30, 2008 |work=The Guardian |access-date=2008-08-30 |archive-url=https://web.archive.org/web/20150206073230/http://www.theguardian.com/society/2008/aug/30/mmr.health.media |archive-date=February 6, 2015 |location=London}} [http://www.badscience.net/2008/08/the-medias-mmr-hoax/ Alt URL]</ref> which sparked the [[Social:MMR vaccine controversy|MMR vaccine controversy]]. Also recently, the [[Medicine:HPV vaccine|HPV vaccine]] has become controversial due to concerns that it may encourage promiscuity when given to 11- and 12-year-old girls.<ref>{{Cite news |url=https://www.npr.org/2011/09/19/140543977/hpv-vaccine-the-science-behind-the-controversy |title=HPV Vaccine: The Science Behind The Controversy |last=Knox, Richard |newspaper=NPR.org |date=September 19, 2011 |publisher=NPR |access-date=September 30, 2015}}</ref><ref>{{Cite journal |vauthors=Chatterjee A, O'Keefe C |date=May 2010 |title=Current controversies in the USA regarding vaccine safety |journal=Expert Review of Vaccines |volume=9 |issue=5 |pages=497–502 |doi=10.1586/erv.10.36 |pmid=20450324 |s2cid=24443783}}</ref>

Arguments against vaccines in the 21st century are often similar to those of 19th-century anti-vaccinationists.<ref name="wolfesharp" /> Around 2014, anti-vaccine rhetoric shifted from being mostly scientific and medical arguments, such as the idea that vaccines were harming children, to political arguments, such as what David Broniatowski of George Washington University has called a "don't-tell-me-what-to-do freedom movement." At the same time, according to Renée DiResta, a researcher at the Stanford Internet Observatory, anti-vaxxers began networking with [[Social:Tea Party movement|Tea Party]] and Second Amendment activists in a "weird [[Philosophy:Libertarianism|libertarian]] crossover". This happened partly due to anti-vaccine medical arguments failing to stop the passage of [[Medicine:California Senate Bill 277|SB277]] in California.<ref name=":8">{{Cite news |last=Velasquez-Manoff |first=Moises |date=2022-05-25 |title=The Anti-Vaccine Movement's New Frontier |language=en-US |work=The New York Times |url=https://www.nytimes.com/2022/05/25/magazine/anti-vaccine-movement.html |access-date=2022-06-02 |issn=0362-4331}}</ref>

====COVID-19====
[[File:Antivax protest in London 2.jpg|thumb|A protest against COVID-19 vaccination in [[Place:London|London]], United Kingdom]]
In mid-2020, surveys on whether people would be willing to take a potential [[Medicine:COVID-19 vaccine|COVID-19 vaccine]] estimated that 67% or 80% of people in the US would accept a new vaccination against COVID-19.<ref name="malik">{{cite journal |last1=Malik |first1=Amyn A |last2=McFadden |first2=SarahAnn M |last3=Elharake |first3=Jad |last4=Omer |first4=Saad B |title=Determinants of COVID-19 vaccine acceptance in the US |journal=EClinicalMedicine, the Lancet |year=2020 |volume=26 |issn=2589-5370 |doi=10.1016/j.eclinm.2020.100495 |page=100495 |pmid=32838242 |pmc=7423333 | doi-access=free}}</ref><ref>Linda Thunström, Madison Ashworth, David Finnoff, and Stephen C. Newbold. 2020. Hesitancy towards a COVID-19 vaccine and prospects for herd immunity. [https://cepr.org/file/9287/download?token=Ba6cin7P ''Covid Economics'' 35] {{Webarchive|url=https://web.archive.org/web/20201011085731/https://cepr.org/file/9287/download?token=Ba6cin7P |date=October 11, 2020 }}: 7 July 2020</ref>

In the United Kingdom, a 16 November 2020 YouGov poll showed that 42% said they were very likely to take the vaccine and 25% were fairly likely (67% likely overall); 11% would be very unlikely and 10% fairly unlikely (21% unlikely overall) and 12% are unsure.<ref name="McDonnell_YouGov">{{cite web |last1=McDonnell |first1=Adam |title=How many Britons are willing to take a coronavirus vaccine? |url=https://yougov.co.uk/topics/health/articles-reports/2020/11/16/how-many-britons-are-willing-take-coronavirus-vacc |website=YouGov |access-date=10 December 2020 |language=en-gb |date=16 November 2020}}</ref> There have been a number of reasons expressed why people might not wish to take COVID-19 vaccines, such as concerns over safety, self-perception of being "low risk", or questioning the Pfizer-BioNTech vaccine in particular. 8% of those reluctant to take it say it is because they oppose vaccinations overall; this amounts to just 2% of the British public.<ref name="McDonnell_YouGov"/>

A December 2020 [[Company:Ipsos|Ipsos]]/[[Organization:World Economic Forum|World Economic Forum]] 15-country poll asked online respondents whether they agreed with the statement: "If a vaccine for COVID-19 were available, I would get it." Rates of agreement were smallest in France (40%), Russia (43%) and South Africa (53%). In the United States, 69% of those polled agreed with the statement; rates were even higher in Britain (77%) and China (80%).<ref>{{cite news |title=Less than half of French want Covid vaccine: poll |url=https://news.yahoo.com/less-half-french-want-covid-173848670.html |access-date=31 December 2020 |work=Yahoo News |agency=AFP |date=29 December 2020}}</ref><ref>{{cite web |title=U.S. and U.K. are optimistic indicators for COVID-19 vaccination uptake |url=https://www.ipsos.com/en/global-attitudes-covid-19-vaccine-december-2020 |website=Ipsos |access-date=31 December 2020 |language=en |archive-date=July 18, 2021 |archive-url=https://web.archive.org/web/20210718141218/https://www.ipsos.com/en/global-attitudes-covid-19-vaccine-december-2020 |url-status=dead }}</ref>

A March 2021 NPR/PBS NewsHour/Marist poll found the difference between white and black Americans to be within the margin of error, but 47% of Trump supporters said they would refuse a COVID-19 vaccine, compared to 30% of all adults.<ref>{{Cite news |url=https://www.npr.org/sections/coronavirus-live-updates/2021/03/12/976172586/little-difference-in-vaccine-hesitancy-among-white-and-black-americans-poll-find |title=Little Difference In Vaccine Hesitancy Among White And Black Americans, Poll Finds |newspaper=NPR |date=March 12, 2021|last1=Summers |first1=Juana }}</ref>

In May 2021, a report titled "Global attitudes towards a COVID-19 vaccine" from the Institute of Global Health Innovation and Imperial College London, which included detailed survey data from March to May 2021 including survey data from 15 countries Australia, Canada, Denmark, France, Germany, Israel, Italy, Japan, Norway, Singapore, South Korea, Spain, Sweden, the UK, and the US. It found that in 13 of the 15 countries more than 50% of people were confident in COVID-19 vaccines. In the UK 87% of survey respondents said they trusted the vaccines, which showed a significant increase in confidence following earlier less reliable polls. The survey also found trust in different vaccine brands varied, with the Pfizer–BioNTech COVID-19 vaccine being the most trusted across all age groups in most countries and particularly the most trusted for under 65s.<ref>{{cite journal |last1=Mahase |first1=Elisabeth |title=Covid-19: UK has highest vaccine confidence and Japan and South Korea the lowest, survey finds |journal=BMJ |date=4 June 2021 |volume=373 |pages=n1439 |doi=10.1136/bmj.n1439 |pmid=34088703 |url=https://www.bmj.com/content/373/bmj.n1439 |access-date=14 June 2021|doi-access=free }}</ref><ref>{{cite web |author1=Institute of Global Health Innovation |title=Global attitudes towards a COVID-19 vaccine |url=https://www.imperial.ac.uk/media/imperial-college/institute-of-global-health-innovation/GlobalVaccineInsights_ICL-YouGov-Covid-19-Behaviour-Tracker_20210520_v2.pdf |website=Imperial College London |publisher=Covid Data Hub |date=May 2021 |access-date=14 June 2021}}</ref>

A January 2022 report from ''{{wipe|Time (magazine)}}'' magazine noted that the anti-vaccine movement "has repositioned itself as an opposition to mandates and government overreach."<ref>{{Cite magazine |last=Bergengruen |first=Vera |date=2022-01-26 |title=How the Anti-Vax Movement Is Taking Over the Right |url=https://time.com/6141699/anti-vaccine-mandate-movement-rally/ |access-date=2022-07-16 |magazine={{wipe|Time (magazine)}} |language=en}}</ref> A May 2022 report from ''{{wipe|The New York Times}}'' noted that "A wave of parents has been radicalized by Covid-era misinformation to reject ordinary childhood immunizations — with potentially lethal consequences."<ref name=":8" />

==Geographical distribution==
[[File:Share that agrees that vaccines are important for children to have (Wellcome Trust (2019)), OWID.svg|thumb|upright=1.5|Share that agrees that vaccines are important for children to have (2018)]]

Vaccine hesitancy is becoming an increasing concern, particularly in industrialized nations. For example, one study surveying parents in Europe found that 12–28% of surveyed parents expressed doubts about vaccinating their children.<ref name="Attwell2018">{{Cite journal |last1=Attwell |first1=K |last2=Wiley |first2=KE |last3=Waddington |first3=C |last4=Leask |first4=J |last5=Snelling |first5=T |date=October 2018 |title=Midwives' attitudes, beliefs and concerns about childhood vaccination: A review of the global literature. |journal=Vaccine |volume=36 |issue=44 |pages=6531–39 |doi=10.1016/j.vaccine.2018.02.028 |pmid=29483029|s2cid=3591014 }}</ref> Several studies have assessed socioeconomic and cultural factors associated with vaccine hesitancy. Both high and low [[Social:Socioeconomic status|socioeconomic status]] as well as high and low education levels have all been associated with vaccine hesitancy in different populations.<ref name="Edwards2016" /><ref>{{Cite journal |vauthors=Pearce A, Law C, Elliman D, Cole TJ, Bedford H |date=April 2008 |title=Factors associated with uptake of measles, mumps, and rubella vaccine (MMR) and use of single antigen vaccines in a contemporary UK cohort: prospective cohort study |journal=BMJ |volume=336 |issue=7647 |pages=754–57 |doi=10.1136/bmj.39489.590671.25 |pmc=2287222 |pmid=18309964}}</ref><ref>{{Cite journal |vauthors=Yang YT, Delamater PL, Leslie TF, Mello MM |date=January 2016 |title=Sociodemographic Predictors of Vaccination Exemptions on the Basis of Personal Belief in California |journal=American Journal of Public Health |volume=106 |issue=1 |pages=172–77 |doi=10.2105/AJPH.2015.302926 |pmc=4695929 |pmid=26562114}}</ref><ref name="sciencedirect.com">{{cite journal |last1=Toll |first1=Mathew |last2=Li |first2=Ang |title=Vaccine sentiments and under-vaccination: Attitudes and behaviour around Measles, Mumps, and Rubella vaccine (MMR) in an Australian cohort |journal=Vaccine |date=2020 |volume=39 |issue=4 |pages=751–759 |doi=10.1016/j.vaccine.2020.11.021 |pmid=33218781 |s2cid=227100012 |url=https://www.sciencedirect.com/science/article/pii/S0264410X20314614}}</ref><ref>{{Cite journal |vauthors=Ogilvie G, Anderson M, Marra F, McNeil S, Pielak K, Dawar M, McIvor M, Ehlen T, Dobson S, Money D, Patrick DM, Naus M |date=May 2010 |title=A population-based evaluation of a publicly funded, school-based HPV vaccine program in British Columbia, Canada: parental factors associated with HPV vaccine receipt |journal=PLOS Medicine |volume=7 |issue=5 |pages=e1000270 |doi=10.1371/journal.pmed.1000270 |pmc=2864299 |pmid=20454567 |doi-access=free }}</ref><ref>{{Cite journal |vauthors=Amit Aharon A, Nehama H, Rishpon S, Baron-Epel O |date=April 2017 |title=Parents with high levels of communicative and critical health literacy are less likely to vaccinate their children |journal=Patient Education and Counseling |volume=100 |issue=4 |pages=768–75 |doi=10.1016/j.pec.2016.11.016 |pmid=27914735}}</ref><ref>{{Cite journal |vauthors=Kim SS, Frimpong JA, Rivers PA, Kronenfeld JJ |date=February 2007 |title=Effects of maternal and provider characteristics on up-to-date immunization status of children aged 19 to 35 months |journal=American Journal of Public Health |volume=97 |issue=2 |pages=259–66 |doi=10.2105/AJPH.2005.076661 |pmc=1781415 |pmid=17194865}}</ref> Other studies examining various populations around the world in different countries found that both high and low socioeconomic status are associated with vaccine hesitancy.<ref name="Larson2014" />

Studies have demonstrated that children of parents who refused the [[Medicine:Pertussis vaccine|pertussis vaccine]], [[Medicine:Varicella vaccine|varicella vaccine]], and [[Medicine:Pneumococcal vaccine|pneumococcal vaccine]] are 23 times more likely to contract pertussis (whooping cough), nine times more likely to catch varicella (chickenpox), and six times more likely to be hospitalized with severe pneumonia from ''[[Biology:Streptococcus pneumoniae|Streptococcus pneumoniae]]'' (pneumococcus).<ref name="McClure2017" />

=== Migrant populations ===
Migrants and refugees arriving and living in Europe face various difficulties in getting vaccinated and many of them are not fully vaccinated. People arriving from Africa, Eastern Europe, the Eastern Mediterranean, and Asia are more likely to be under-vaccinated (partial or delayed vaccination). Also, recently arrived refugees, migrants and seekers of asylum were less likely to be fully vaccinated than other people from the same groups. Those with little contact to healthcare services, no citizenship and lower income are also more likely to be under-vaccinated.<ref name=":02">{{Cite journal |date=2022-12-20 |title=How to increase vaccination uptake among migrant communities |url=https://evidence.nihr.ac.uk/alert/how-to-increase-vaccination-uptake-migrant-communities/ |journal=NIHR Evidence |language=en |doi=10.3310/nihrevidence_55367|s2cid=254969959 }}</ref><ref name=":12">{{Cite journal |last1=Crawshaw |first1=Alison F |last2=Farah |first2=Yasmin |last3=Deal |first3=Anna |last4=Rustage |first4=Kieran |last5=Hayward |first5=Sally E |last6=Carter |first6=Jessica |last7=Knights |first7=Felicity |last8=Goldsmith |first8=Lucy P |last9=Campos-Matos |first9=Ines |last10=Wurie |first10=Fatima |last11=Majeed |first11=Azeem |last12=Bedford |first12=Helen |last13=Forster |first13=Alice S |last14=Hargreaves |first14=Sally |date=September 2022 |title=Defining the determinants of vaccine uptake and undervaccination in migrant populations in Europe to improve routine and COVID-19 vaccine uptake: a systematic review |journal=The Lancet Infectious Diseases |language=en |volume=22 |issue=9 |pages=e254–e266 |doi=10.1016/S1473-3099(22)00066-4 |pmc=9007555 |pmid=35429463}}</ref>

Vaccination barriers for migrants include language/literacy barriers, lack of understanding of the need for or their entitlement to vaccines, concerns about the side-effects, health professionals lack of knowledge of vaccination guidelines for migrants, and practical/legal issues, for example, having no fixed address. Vaccines uptake of migrants can be increased by customised communications, clear policies, community-guided interventions (such as vaccine advocates), and vaccine offers in local accessible settings.<ref name=":02" /><ref name=":12" />

=== Australia ===
An Australian study that examined the factors associated with vaccine attitudes and uptake separately found that under-vaccination correlated with lower socioeconomic status but not with negative attitudes towards vaccines. The researchers suggested that practical barriers are more likely to explain under-vaccination among individuals with lower socioeconomic status.<ref name="sciencedirect.com" /> A 2012 Australian study found that 52% of parents had concerns about the safety of vaccines.<ref>{{Cite journal |last1=My |first1=Chow |last2=Danchin |first2=Margie |last3=Willaby |first3=Harold W. |last4=Pemberton |first4=Sonya |last5=Leask |first5=Julie |date=March 2017 |title=Parental attitudes, beliefs, behaviours and concerns towards childhood vaccinations in Australia: A national online survey |url=https://pubmed.ncbi.nlm.nih.gov/28260278 |journal=Australian Family Physician |volume=46 |issue=3 |pages=145–151 |issn=0300-8495 |pmid=28260278}}</ref>

==Policy implications==
{{Further|Medicine:Vaccination policy}}

Multiple major medical societies including the [[Organization:Infectious Diseases Society of America|Infectious Diseases Society of America]], the American Medical Association, and the American Academy of Pediatrics support the elimination of all nonmedical exemptions for childhood vaccines.<ref name="Edwards2016" />

===Individual liberty===
Compulsory vaccination policies have been controversial as long as they have existed, with opponents of mandatory vaccinations arguing that governments should not infringe on an individual's freedom to make medical decisions for themselves or their children, while proponents of compulsory vaccination cite the well-documented public health benefits of vaccination.<ref name="wolfesharp" /><ref>{{Cite journal |vauthors=Colgrove J, Bayer R |date=April 2005 |title=Manifold restraints: liberty, public health, and the legacy of Jacobson v Massachusetts |journal=American Journal of Public Health |volume=95 |issue=4 |pages=571–76 |doi=10.2105/AJPH.2004.055145 |pmc=1449222 |pmid=15798111}}</ref> Others argue that, for compulsory vaccination to effectively prevent disease, there must be not only available vaccines and a population willing to immunize, but also sufficient ability to decline vaccination on grounds of personal belief.<ref>{{Cite journal |vauthors=Salmon DA, Teret SP, MacIntyre CR, Salisbury D, Burgess MA, Halsey NA |date=February 2006 |title=Compulsory vaccination and conscientious or philosophical exemptions: past, present, and future |journal=Lancet |volume=367 |issue=9508 |pages=436–42 |doi=10.1016/s0140-6736(06)68144-0 |pmid=16458770 |s2cid=19344405}}</ref>

Vaccination policy involves complicated ethical issues, as unvaccinated individuals are more likely to contract and spread disease to people with weaker immune systems, such as young children and the elderly, and to other individuals in whom the vaccine has not been effective. However, mandatory vaccination policies raise ethical issues regarding parental rights and [[Philosophy:Informed consent|informed consent]].<ref>{{Cite journal |url=https://www.who.int/bulletin/volumes/91/4/12-113480/en/ |archive-url=https://web.archive.org/web/20140912112515/http://www.who.int/bulletin/volumes/91/4/12-113480/en/ |url-status=dead |archive-date=September 12, 2014 |title=Ethical considerations for vaccination programmes in acute humanitarian emergencies |last1=Moodley |first1=Keymanthri |last2=Hardie |first2=Kate |date=7 February 2013 |journal=Bulletin of the World Health Organization |last3=Selgelid |first3=Michael J. |last4=Waldman |first4=Ronald J. |last5=Strebel |first5=Peter |last6=Rees |first6=Helen |last7=Durrheim |first7=David N. |volume=91 |issue=4 |pages=290–97 |doi=10.2471/BLT.12.113480 |pmid=23599553 |pmc=3629456 |author-link6=Helen Rees}}</ref>

In the United States, vaccinations are not truly compulsory, but they are typically required in order for children to attend public schools. As of January 2021, five states{{snd}}Mississippi, West Virginia, [[Medicine:California Senate Bill 277|California]], [[Medicine:2020 Maine Question 1|Maine]], and New York{{snd}}have eliminated religious and philosophical exemptions to required school immunizations.<ref>{{cite web |title=States With Religious and Philosophical Exemptions From School Immunization Requirements |url=https://www.ncsl.org/research/health/school-immunization-exemption-state-laws.aspx |website=National Conference of State Legislatures |access-date=2 January 2021 |archive-url=https://archive.today/20201022191725/https://www.ncsl.org/research/health/school-immunization-exemption-state-laws.aspx |archive-date=22 October 2020}}</ref>

===Children's rights===
{{Further|Social:Mature minor doctrine|Medicine:Gillick competence}}

Medical [[Philosophy:Ethicist|ethicist]] [[Biography:Arthur Caplan|Arthur Caplan]] argues that children have a right to the best available medical care, including vaccines, regardless of parental feelings toward vaccines, saying "Arguments about medical freedom and choice are at odds with the human and constitutional rights of children. When parents won't protect them, governments must."<ref>{{Cite journal |last=Caplan |first=Arthur L |title=Do Children Have Vaccination Rights? |url=https://www.medscape.com/viewarticle/902956 |journal=Medscape Business of Medicine |name-list-style=vanc}}</ref><ref>{{Cite web |url=https://www.seattletimes.com/opinion/anti-vaccine-misinformation-denies-childrens-rights/ |title=Anti-vaccine misinformation denies children's rights |date=2018-04-18}}</ref>

A review of American court cases from 1905 to 2016 found that, of the nine courts that have heard cases regarding whether not vaccinating a child constitutes neglect, seven have held vaccine refusal to be a form of child neglect.<ref>{{Cite journal |vauthors=Parasidis E, Opel DJ |date=January 2017 |title=Parental Refusal of Childhood Vaccines and Medical Neglect Laws |journal=American Journal of Public Health |volume=107 |issue=1 |pages=68–71 |doi=10.2105/AJPH.2016.303500 |pmc=5308147 |pmid=27854538}}</ref>

To prevent the spread of disease by unvaccinated individuals, some schools and doctors' surgeries have prohibited unvaccinated children from being enrolled, even where not required by law.<ref>{{Cite web |url=http://live.huffingtonpost.com/r/segment/should-pediatricians-refuse-unvaccinated-kids/53285f162b8c2a24f700070f |title=Should Pediatricians Refuse Unvaccinated Kids? |website=The Huffington Post |access-date=July 4, 2015}}</ref><ref>{{Cite web |url=http://www.medicaldaily.com/nyc-schools-are-now-allowed-ban-unvaccinated-kids-rules-federal-judge-289614 |title=NYC Schools Are Now Allowed To Ban Unvaccinated Kids, Rules Federal Judge |last=Bachai |first=Sabrina |date=24 June 2014 |website=Medical Daily |access-date=4 July 2015}}</ref> Refusal of doctors to treat unvaccinated children may cause harm to both the child and public health, and may be considered unethical, if the parents are unable to find another healthcare provider for the child.<ref>{{Cite journal |last1=Halperin |first1=Beth |last2=Melnychuk |first2=Ryan |last3=Downie |first3=Jocelyn |last4=Macdonald |first4=Noni |date=December 2007 |title=When is it permissible to dismiss a family who refuses vaccines? Legal, ethical and public health perspectives |journal=Paediatrics & Child Health |volume=12 |issue=10 |pages=843–45 |doi=10.1093/pch/12.10.843 |pmc=2532570 |pmid=19043497}}</ref> Opinion on this is divided, with the largest professional association, the American Academy of Pediatrics, saying that exclusion of unvaccinated children may be an option under narrowly defined circumstances.<ref name="Edwards2016">{{Cite journal |last1=Edwards |first1=Kathryn M. |last2=Hackell |first2=Jesse M. |title=Countering Vaccine Hesitancy |journal=Pediatrics |year=2016 |volume=138 |issue=3 |pages=e20162146 |doi=10.1542/peds.2016-2146 |pmid=27573088 |doi-access=free}}</ref>

==Religion==
{{Main|Medicine:Vaccination and religion}}

Since most religions predate the invention of vaccines, scriptures do not specifically address the topic of vaccination.<ref name="Smith2015" /> However, vaccination has been opposed by some on religious grounds ever since it was first introduced. When vaccination was first becoming widespread, some Christian opponents argued that preventing smallpox deaths would be thwarting God's will and that such prevention is sinful.<ref name="Early">Early religious opposition:
*{{cite book |chapter=Theological opposition to inoculation, vaccination, and the use of anæsthetics |title=A History of the Warfare of Science with Theology in Christendom |author=White AD |location=New York |publisher=Appleton |year=1896 |chapter-url=http://abob.libs.uga.edu/bobk/whitem10.html |access-date=July 22, 2007 |archive-date=September 17, 2008 |archive-url=https://web.archive.org/web/20080917184044/http://abob.libs.uga.edu/bobk/whitem10.html |url-status=dead }}
*{{cite journal |vauthors=Bazin H |title=The ethics of vaccine usage in society: lessons from the past |journal=Endeavour |volume=25 |issue=3 |pages=104–08 |date=September 2001 |pmid=11725304 |doi=10.1016/S0160-9327(00)01376-4}}
*{{cite journal |vauthors=Noble M |title=Ethics in the trenches: a multifaceted analysis of the stem cell debate |journal=Stem Cell Reviews |volume=1 |issue=4 |pages=345–76 |date=December 2005 |pmid=17142878 |doi=10.1385/SCR:1:4:345 |citeseerx=10.1.1.465.2410 |s2cid=21775014}}</ref> Opposition from some religious groups continues to the present day, on various grounds, raising ethical difficulties when the number of unvaccinated children threatens harm to the entire population.<ref name="May">{{Cite journal |vauthors=May T, Silverman RD |year=2005 |title=Free-riding, fairness and the rights of minority groups in exemption from mandatory childhood vaccination |journal=Human Vaccines |volume=1 |issue=1 |pages=12–15 |doi=10.4161/hv.1.1.1425 |pmid=17038833 |s2cid=39321188|doi-access=free }}</ref> Many governments allow parents to opt out of their children's otherwise mandatory vaccinations for religious reasons; some parents falsely claim religious beliefs to get vaccination exemptions.<ref>{{Cite news |url=https://www.usatoday.com/news/nation/2007-10-17-19819928_x.htm |title=Parents use religion to avoid vaccines |last=LeBlanc S |date=2007-10-17 |work=USA Today |access-date=2007-11-24}}</ref>

Many Jewish community leaders support vaccination.<ref>[https://www.ou.org/news/statement-vaccinations-ou-rabbinical-council-america/ "Statement on Vaccinations from the OU and Rabbinical Council of America."] ''Orthodox Union''. 14 November 2018. 21 May 2019.</ref> Among early Hasidic leaders, Rabbi Nachman of Breslov (1772–1810) was known for his criticism of the doctors and medical treatments of his day. However, when the first vaccines were successfully introduced, he stated: "Every parent should have his children vaccinated within the first three months of life. Failure to do so is tantamount to murder. Even if they live far from the city and have to travel during the great winter cold, they should have the child vaccinated before three months."<ref>Avaneha Barzel p. 31 #34</ref>

Although [[Biology:Gelatin|gelatin]] can be derived from many animals, Jewish and Islamic scholars have determined that since the gelatin is cooked and not consumed as food, vaccinations containing gelatin are acceptable.<ref name="Smith2015" /> However, in 2015 and again in 2020, the possible use of porcine-based gelatin in vaccines raised religious concerns among Muslims and Orthodox Jews about the [[Religion:Halal|halal]] or kosher status of several vaccinations against [[Medicine:COVID-19|COVID-19]].<ref>{{cite news |last1=Milko |first1=Victoria |title=Concern among Muslims over halal status of COVID-19 vaccine |url=https://abcnews.go.com/Health/wireStory/concern-muslims-halal-status-covid-19-vaccine-74826269 |access-date=30 December 2020 |work=ABC News |agency=Associated Press (AP) |date=20 December 2020 |language=en}}</ref> The Muslim Council of Britain argued against the use of intranasal influenza vaccine in 2019 due to the presence of gelatin in the vaccine and consider such vaccines to be non-[[Religion:Halal|halal]] (unclean).<ref>{{cite web|url=https://www.bbc.com/news/health-30118984 |title=Pork gelatine flu spray concerns |author=Priyanka Deladia | date=9 November 2014 | website=BBC}}</ref>

In India, in 2018, a three-minute doctored clip circulated among Muslims claiming that the MR-VAC vaccine against measles and rubella was a "Modi government-[[Organization:Rashtriya Swayamsevak Sangh|RSS]] conspiracy" to stop the population growth of Muslims. The clip was taken from a TV show that exposed the baseless rumors.<ref>{{Cite web |url=https://www.hindustantimes.com/india-news/shot-of-life-saving-vaccination-drive-from-rumours-and-fake-news/story-WHgsXRDorzKxpjPWpdCx7M.html |title=Shot of life: saving vaccination drive from rumours and fake news |date=May 19, 2018 |website=Hindustan Times}}</ref> Hundreds of madrassas in the state of Uttar Pradesh refused permission to health department teams to administer vaccines because of rumors spread using [[Software:WhatsApp|WhatsApp]].<ref>{{Cite news |url=https://timesofindia.indiatimes.com/city/meerut/madrassas-in-west-up-say-no-to-measles-rubella-vaccination/articleshow/67184011.cms |title=Uttar Pradesh: WhatsApp rumours make 100s of UP madrassas reject vaccination |website=The Times of India|date=December 21, 2018 }}</ref>

Some Christians have objected to the use of cell cultures of some viral vaccines, and the virus of the [[Medicine:Rubella|rubella]] vaccine,<ref name="pmid3890107">{{Cite journal |vauthors=Plotkin SA, Buser F |year=1985 |title=History of RA27/3 rubella vaccine |journal=Reviews of Infectious Diseases |volume=7 |issue=Suppl 1 |pages=S77–78 |doi=10.1093/clinids/7.supplement_1.s77 |pmid=3890107}}</ref> on the grounds that they are derived from tissues taken from therapeutic abortions performed in the 1960s. The [[Philosophy:Principle of double effect|principle of double effect]], originated by [[Biography:Thomas Aquinas|Thomas Aquinas]], holds that actions with both good and bad consequences are morally acceptable in specific circumstances.<ref>{{Cite journal |last=Grabenstein JD |year=1999 |title=Moral considerations with certain viral vaccines |url=http://www.immunizationinfo.org/files/nnii/files/Moral_Considerations_With_Certain_Viral_Vaccines.pdf |url-status=dead |journal=Christ Pharm |volume=2 |issue=2 |pages=3–6 |archive-url=https://web.archive.org/web/20110718001330/http://www.immunizationinfo.org/files/nnii/files/Moral_Considerations_With_Certain_Viral_Vaccines.pdf |archive-date=July 18, 2011 |access-date=2009-05-11 |df=mdy-all}}</ref> The Vatican Curia has said that for vaccines originating from embryonic cells, Catholics have "a grave responsibility to use alternative vaccines and to make a conscientious objection", but concluded that it is acceptable for Catholics to use the existing vaccines until an alternative becomes available.<ref name="Vatican">{{Cite journal |last=Pontifical Academy for Life |year=2005 |title=Moral reflections on vaccines prepared from cells derived from aborted human foetuses |url=http://www.academiavita.org/template.jsp?sez=Documenti&pag=testo/vacc/vacc&lang=english |url-status=dead |journal=Medicina e Morale |archive-url=https://web.archive.org/web/20060507072740/http://www.academiavita.org/template.jsp?sez=Documenti&pag=testo%2Fvacc%2Fvacc&lang=english |archive-date=May 7, 2006 |access-date=2008-12-03 |df=mdy-all }}</ref>

In the United States, some parents falsely claim religious exemptions when their real motivation for avoiding vaccines is supposed safety concerns.<ref name="cbs-fake">{{Cite news |url=https://www.cbsnews.com/news/parents-fake-religion-to-avoid-vaccines/ |title=Parents Fake Religion To Avoid Vaccines |date=17 October 2007 |agency=AP |website=CBS News}}</ref> For a number of years, only Mississippi, West Virginia, and California did not provide religious exemptions. Following the 2019 measles outbreaks, Maine and New York repealed their religious exemptions, and the state of Washington did so for the measles vaccination.<ref>{{Cite web |url=http://vaccines.procon.org/view.resource.php?resourceID=003597 |title=State Vaccination Exemptions for Children Entering Public Schools |website=Vaccines.procon.org}}</ref>

According to a March 2021 poll conducted by The Associated Press/NORC, vaccine skepticism is more widespread among white evangelicals than most other blocs of Americans. Forty percent of white evangelical Protestants said they were not likely to get vaccinated against COVID-19.<ref>{{Cite web |date=2021-04-05 |title=Vaccine skepticism runs deep among white evangelicals in US |url=https://apnews.com/article/coronavirus-vaccine-skepticism-white-evangelicals-us-32898166bbb673ad87842af24c8daefb|access-date=2021-04-07 |website=AP NEWS}}</ref>

==Alternative medicine==
{{Alternative medicine sidebar}}

Many forms of [[Medicine:Alternative medicine|alternative medicine]] are based on philosophies that oppose vaccination (including [[Biology:Germ theory denialism|germ theory denialism]]) and have practitioners who voice their opposition. As a consequence, the increase in popularity of alternative medicine in the 1970s planted the seeds of the modern anti-vaccination movement.<ref>{{Cite web |url=https://www.theatlantic.com/magazine/archive/2019/08/measles-as-metaphor/592756/ |title=What the Measles Epidemic Really Says About America |last=Beinart |first=Peter |date=August 2019 |website=The Atlantic |access-date=July 8, 2019}}</ref> More specifically, some elements of the [[Unsolved:Chiropractic|chiropractic]] community, some [[Unsolved:Homeopathy|homeopaths]], and [[Unsolved:Naturopathy|naturopaths]] developed anti-vaccine rhetoric.<ref name="Ernst">{{Cite journal |vauthors=Ernst E |date=October 2001 |title=Rise in popularity of complementary and alternative medicine: reasons and consequences for vaccination |journal=Vaccine |volume=20 |issue=Suppl 1 |pages=S90–93; discussion S89 |doi=10.1016/S0264-410X(01)00290-0 |pmid=11587822}}</ref> The reasons for this negative vaccination view are complicated and rest at least in part on the early philosophies that shaped the foundation of these groups.<ref name="Ernst" />

===Chiropractic===
Historically, chiropractic strongly opposed vaccination based on its belief that all diseases were traceable to causes in the spine and therefore could not be affected by vaccines. Daniel D. Palmer (1845–1913), the founder of chiropractic, wrote: "It is the very height of absurdity to strive to 'protect' any person from smallpox or any other malady by inoculating them with a filthy animal poison."<ref name="Busse" /> Vaccination remains controversial within the profession.<ref name="Campbell" /> Most chiropractic writings on vaccination focus on its negative aspects.<ref name="Busse" /> A 1995 survey of US chiropractors found that about one third believed there was no scientific proof that immunization prevents disease.<ref name="Campbell">{{Cite journal |vauthors=Campbell JB, Busse JW, Injeyan HS |date=April 2000 |title=Chiropractors and vaccination: A historical perspective |url=http://pediatrics.aappublications.org/cgi/content/full/105/4/e43 |journal=Pediatrics |volume=105 |issue=4 |pages=E43 |doi=10.1542/peds.105.4.e43 |pmid=10742364|doi-access=|s2cid=14561867 }}</ref> While the Canadian Chiropractic Association supports vaccination,<ref name="Busse">{{Cite journal |vauthors=Busse JW, Morgan L, Campbell JB |date=June 2005 |title=Chiropractic antivaccination arguments |url=http://jmptonline.org/article/S0161-4754(05)00111-9/fulltext |journal=Journal of Manipulative and Physiological Therapeutics |volume=28 |issue=5 |pages=367–73 |doi=10.1016/j.jmpt.2005.04.011 |pmid=15965414}}</ref> a survey in Alberta in 2002 found that 25% of chiropractors advised patients for, and 27% advised against, vaccinations for patients or for their children.<ref>{{Cite journal |vauthors=Russell ML, Injeyan HS, Verhoef MJ, Eliasziw M |date=December 2004 |title=Beliefs and behaviours: understanding chiropractors and immunization |journal=Vaccine |volume=23 |issue=3 |pages=372–79 |doi=10.1016/j.vaccine.2004.05.027 |pmid=15530683}}</ref>

Although most chiropractic colleges try to teach about vaccination in a manner consistent with scientific evidence, several have faculty who seem to stress negative views.<ref name="Campbell" /> A survey of a 1999–2000 cross-section of students of Canadian Memorial Chiropractic College (CMCC), which does not formally teach anti-vaccination views, reported that fourth-year students opposed vaccination more strongly than did first-year students, with 29.4% of fourth-year students opposing vaccination.<ref>{{Cite journal |vauthors=Busse JW, Wilson K, Campbell JB |date=November 2008 |title=Attitudes towards vaccination among chiropractic and naturopathic students |journal=Vaccine |volume=26 |issue=49 |pages=6237–43 |doi=10.1016/j.vaccine.2008.07.020 |pmid=18674581}}</ref> A follow-up study on 2011–12 CMCC students found that pro-vaccination attitudes heavily predominated. Students reported support rates ranging from 84% to 90%. One of the study's authors proposed the change in attitude to be due to the lack of the previous influence of a "subgroup of some charismatic students who were enrolled at CMCC at the time, students who championed the Palmer postulates that advocated against the use of vaccination".<ref>{{Cite journal |vauthors=Lameris M, Schmidt C, Gleberzon B, Ogrady J |date=September 2013 |title=Attitudes toward vaccination: A cross-sectional survey of students at the Canadian Memorial Chiropractic College |journal=The Journal of the Canadian Chiropractic Association |volume=57 |issue=3 |pages=214–20 |pmc=3743647 |pmid=23997247}}</ref>

====Policy positions====
The American Chiropractic Association and the International Chiropractic Association support individual exemptions to compulsory vaccination laws.<ref name="Campbell" /> In March 2015, the Oregon Chiropractic Association invited [[Biography:Andrew Wakefield|Andrew Wakefield]], chief author of a [[Social:MMR vaccine controversy|fraudulent research paper]], to testify against Senate Bill 442,<ref name="Yoo">{{Citation |last=Yoo |first=Saerom |title=Vaccine researcher Wakefield to testify in Oregon |date=February 24, 2015 |url=http://www.statesmanjournal.com/story/news/health/2015/02/24/andrew-wakefield-vaccine-oregon/23967797/ |work=Statesman Journal |access-date=March 3, 2015 |name-list-style=vanc}}</ref> "a bill that would eliminate nonmedical exemptions from Oregon's school immunization law".<ref name="Yoo_canceled">{{Citation |last=Yoo |first=Saerom |title=Meeting on vaccine mandate bill canceled |date=February 26, 2015 |url=http://www.statesmanjournal.com/story/news/health/2015/02/25/meeting-vaccine-mandate-bill-canceled/24020213/ |work=Statesman Journal |access-date=March 3, 2015 |name-list-style=vanc}}</ref> The California Chiropractic Association lobbied against a 2015 bill ending belief exemptions for vaccines. They had also opposed a 2012 bill related to vaccination exemptions.<ref name="Mason">
{{cite web |last=Mason |first=Melanie | name-list-style = vanc |date=March 5, 2015 |title=Chiropractors lobby against bill ending belief exemptions for vaccines |work=Los Angeles Times |url=https://www.latimes.com/local/political/la-me-pc-vaccine-bill-chiropractors-20150305-story.html |access-date=March 6, 2015}}
</ref>

===Homeopathy===

Several surveys have shown that some practitioners of [[Unsolved:Homeopathy|homeopathy]], particularly homeopaths without any medical training, advise patients against vaccination.<ref>{{Cite journal |vauthors=Schmidt K, Ernst E |date=March 2003 |title=MMR vaccination advice over the Internet |journal=Vaccine |volume=21 |issue=11–12 |pages=1044–47 |doi=10.1016/S0264-410X(02)00628-X |pmid=12559777}}</ref> For example, a survey of registered homeopaths in Austria found that only 28% considered immunization an important preventive measure, and 83% of homeopaths surveyed in Sydney, Australia, did not recommend vaccination.<ref name="Ernst" /> Many practitioners of [[Unsolved:Naturopathy|naturopathy]] also oppose vaccination.<ref name="Ernst" />

Homeopathic "vaccines" (nosodes) are ineffective because they do not contain any active ingredients and thus do not stimulate the immune system. They can be dangerous if they take the place of effective treatments.<ref name="SciMed">{{Cite web |url=http://www.sciencebasedmedicine.org/?p=8003 |title=Homeopathic Vaccines |last=Crislip |first=Mark |date=November 5, 2010 |name-list-style=vanc}}</ref> Some medical organizations have taken action against nosodes. In Canada, the labeling of homeopathic nosodes require the statement: "This product is neither a vaccine nor an alternative to vaccination."<ref name="StopNosodes">{{Cite web |url=http://www.stopnosodes.org/the-problem/the-extent-of-nosode-use-in-canada/ |title=Nosode Use in Canada |last=Stop Nosodes/Bad Science Watch |date=August 2015 |access-date=October 20, 2015 |archive-date=October 26, 2016 |archive-url=https://web.archive.org/web/20161026005548/http://www.stopnosodes.org/the-problem/the-extent-of-nosode-use-in-canada/ |url-status=dead }}</ref>

==Financial motives==
Alternative medicine proponents gain from promoting vaccine conspiracy theories through the sale of ineffective and expensive medications, supplements, and procedures such as [[Unsolved:Chelation therapy|chelation therapy]] and [[Medicine:Hyperbaric medicine|hyperbaric oxygen therapy]], sold as able to cure the 'damage' caused by vaccines.<ref>{{Cite book |title=The Autism Spectrum Disorders / vaccine link debate: a health social movement |last=Kerr MA |publisher=University of Pittsburgh |year=2009 |pages=194–203 |chapter=Movement impact |access-date=2010-02-25 |chapter-url=http://etd.library.pitt.edu/ETD/available/etd-04302009-115908/unrestricted/Kerr_FINAL.pdf |archive-url=https://web.archive.org/web/20110718173710/http://etd.library.pitt.edu/ETD/available/etd-04302009-115908/unrestricted/Kerr_FINAL.pdf |archive-date=July 18, 2011}}</ref> Homeopaths in particular gain through the promotion of water injections or 'nosodes' that they allege have a 'natural' vaccine-like effect.<ref>{{Cite news |url=https://www.theglobeandmail.com/news/national/health-experts-question-lack-of-crackdown-on-homeopathic-vaccines/article23019800/ |title=Health experts question lack of crackdown on 'homeopathic vaccines' |last=Weeks |first=Carly |access-date=July 4, 2015 |website=The Globe and Mail}}</ref> Additional bodies with a vested interest in promoting the "unsafeness" of vaccines may include lawyers and legal groups organizing court cases and class action lawsuits against vaccine providers.

Conversely, alternative medicine providers have accused the vaccine industry of misrepresenting the safety and effectiveness of vaccines, covering up and suppressing information, and influencing health policy decisions for financial gain.<ref name="wolfesharp" /> In the late 20th century, vaccines were a product with low [[Finance:Profit margin|profit margin]]s,<ref name="Sheridan" /> and the number of companies involved in vaccine manufacture declined. In addition to low profits and liability risks, manufacturers complained about low prices paid for vaccines by the CDC and other US government agencies.<ref>{{Cite book |title=Vaccine: the Controversial Story of Medicine's Greatest Lifesaver |last=Allen A |publisher=W.W. Norton |year=2007 |isbn=978-0-393-05911-3 |pages=421–42 |chapter=Epilogue: our best shots |chapter-url=https://archive.org/details/vaccinecontrover00arth}}</ref> In the early 21st century, the vaccine market greatly improved with the approval of the vaccine [[Medicine:Pneumococcal conjugate vaccine|Prevnar]], along with a small number of other high-priced blockbuster vaccines, such as [[Biology:Gardasil|Gardasil]] and Pediarix, which each had sales revenues of over $1 billion in 2008.<ref name="Sheridan">{{Cite journal |vauthors=Sheridan C |date=June 2009 |title=Vaccine market boosters |journal=Nature Biotechnology |volume=27 |issue=6 |pages=499–501 |doi=10.1038/nbt0609-499 |pmid=19513043 |s2cid=205268563}}</ref> Despite high growth rates, vaccines represent a relatively small portion of overall pharmaceutical profits. As recently as 2010, the [[Organization:World Health Organization|World Health Organization]] estimated vaccines to represent 2–3% of total sales for the [[Medicine:Pharmaceutical industry|pharmaceutical industry]].<ref>{{cite web|url=https://www.who.int/influenza_vaccines_plan/resources/session_10_kaddar.pdf | title=Global Vaccine Market Features and Trends |author=Miloud Kaddar}}</ref>

==War==
[[File:"The White Man's Burden" Judge 1899.png|thumb |upright=1.3 |Judge's cartoon of Rudyard Kipling's famous poem "The White Man's Burden" published in 1899. The poem's philosophy quickly was utilized to explain/justify the United States' response to the annexation of the Philippines. The United States used the "white man's burden" as an argument for imperial control of the Philippines and Puerto Rico based on the moral necessity to ensure the spread of civility and modernity.]]

The United States has a very complex history with [[Medicine:Vaccination policy|compulsory vaccination]], particularly in enforcing compulsory vaccinations both domestically and abroad to protect American soldiers during times of war. There are hundreds of thousands of examples of soldier deaths that were not the result of combat wounds but were instead from disease.<ref name=":0">{{Cite book |title=Pox: An American History |last=Willrich |first=Michael |publisher=Penguin Group |year=2010 |isbn=978-1101476222 |location=New York |pages=117–65 |name-list-style=vanc}}</ref> Among wars with high death tolls from disease is the Civil War where an estimated 620,000 soldiers died from disease. American soldiers in other countries have spread diseases that ultimately disrupted entire societies and healthcare systems with famine and poverty.<ref name=":0" />

===Spanish–American War===
The Spanish–American War began in April 1898 and ended in August 1898. During this time the United States gained control of Cuba, Puerto Rico, and the Philippines from Spain. As a military police power and as colonizers the United States took a very hands-on approach in administering healthcare particularly vaccinations to natives during the invasion and conquest of these countries.<ref name=":0" /> Although the Spanish–American War occurred during the era of [[Biology:Germ theory of disease|"bacteriological revolution"]] where knowledge of disease was bolstered by [[Biology:Germ theory of disease|germ theory]], more than half of the soldier casualties in this war were from disease.<ref name=":0" /> Unknowingly, American soldiers acted as agents of disease transmission, fostering bacteria in their haphazardly made camps. These soldiers invaded Cuba, Puerto Rico, and the Philippines and connected parts of these countries that had never before been connected due to low population density, thereby beginning epidemics.<ref name=":0" /> The mobility of American soldiers around these countries encouraged newfound mobility of disease that quickly infected natives.

Military personnel used Rudyard's Kipling's poem "The White Man's Burden" to explain their imperialistic actions in Cuba, the Philippines, and Puerto Rico and the need for the United States to help the "dark-skinned Barbarians"<ref name=":0" /> reach modern sanitary standards. American actions abroad before, during, and after the war emphasized a need for proper sanitation habits especially on behalf of the natives. Natives who refuse to oblige with American health standards and procedures risked fines or imprisonment.<ref name=":0" /> One penalty in Puerto Rico included a $10 fine for a failure to vaccinate and an additional $5 fine for any day a person continued to be unvaccinated; refusal to pay resulted in ten or more days of imprisonment. If entire villages refused the army's current sanitation policy at any given time they risked being burnt to the ground to preserve the health and safety of soldiers from endemic smallpox and yellow fever.<ref name=":0" /> Vaccines were forcibly administered to the Puerto Ricans, Cubans, and Filipinos. Military personnel in Puerto Rico provided Public Health services that culminated in military orders that mandated vaccinations for children before they were six months old and a general vaccination order.<ref name=":0" /> By the end of 1899 in Puerto Rico alone the U.S. military and other hired native vaccinators called ''practicantes'', vaccinated an estimated 860,000 natives in a five-month period. This period began the United States' movement toward an expansion of medical practices that included "tropical medicine" in an attempt to protect the lives of soldiers abroad.<ref name=":0" />

===Vietnam War===
During the Vietnam War, vaccination was necessary for soldiers to fight overseas. Because disease follows soldiers,<ref>Clara E. Councell. "War and Infectious Disease." Public Health Reports, vol. 56, no. 12, 1941, pp. 547–573. JSTOR, www.jstor.org/stable/4583663. Accessed 16 May 2021.</ref> they had to receive vaccines preventing [[Medicine:Cholera|cholera]], influenza, measles, meningococcemia, [[Medicine:Bubonic plague|Bubonic plague]], poliovirus, smallpox, tetanus, diphtheria, typhoid, [[Medicine:Typhus|typhus]], and [[Medicine:Yellow fever|yellow fever]]. However, the diseases mainly prevalent in Vietnam at this time were measles and polio. After arriving in Vietnam, the United States Military conducted the "Military Public Health Assistance Project".<ref>{{Cite journal |last1=Grabenstein |first1=J. D. |last2=Pittman |first2=PR |last3=Greenwood |first3=JT |last4=Engler |first4=RJ |date=1 June 2006 |title=Immunization to Protect the US Armed Forces: Heritage, Current Practice, and Prospects |journal=Epidemiologic Reviews |volume=28 |issue=1 |pages=3–26 |doi=10.1093/epirev/mxj003 |pmid=16763072|doi-access=free}}</ref> This public health program was a joint United States Military and Government of Vietnam concept to create or expand public medical facilities throughout South Vietnam.<ref>{{Cite web |url=http://www.historynet.com/the-night-the-viet-cong-stopped-the-war.htm |title=The Night the Viet Cong Stopped the War |last=Worthington |first=Bob |date=17 March 2011 |website=History Net: Where History Comes Alive – World & US History Online |language=en-US |access-date=18 November 2015 |name-list-style=vanc}}</ref> Local villages in Vietnam were inoculated. The United States military screened patients, dispensed medication, distributed clothing and food, and even passed out propaganda such as comic books.<ref>{{Cite book |title=Profiles of Malaysia's Foreign Ministers. |last1=Rahman |first1=Tunku Abdul |last2=Al-Haj |first2=Putra |date=2008 |publisher=Institute of Diplomacy and Foreign Relations (IDFR), Ministry of Foreign Affairs |isbn=978-9832220268 |location=Kuala Lumpur |oclc=774064073 |name-list-style=vanc}}</ref>

==Information warfare==

An analysis of [[Company:Twitter#Tweets|tweets]] from July 2014 through September 2017 revealed an active campaign on [[Company:Twitter|Twitter]] by the [[Organization:Internet Research Agency|Internet Research Agency]] (IRA), a Russian [[Social:Troll farm|troll farm]] accused of interference in the 2016 U.S. elections, to sow discord about the safety of vaccines.<ref name="WeaponizedHealthCommunication">{{Cite journal |vauthors=Broniatowski DA, Jamison AM, Qi S, AlKulaib L, Chen T, Benton A, Quinn SC, Dredze M |date=October 2018 |title=Weaponized Health Communication: Twitter Bots and Russian Trolls Amplify the Vaccine Debate |journal=American Journal of Public Health |volume=108 |issue=10 |pages=1378–84 |doi=10.2105/AJPH.2018.304567 |pmc=6137759 |pmid=30138075}}</ref><ref>{{Cite news |url=https://www.theguardian.com/society/2018/aug/23/russian-trolls-spread-vaccine-misinformation-on-twitter |title=Russian trolls 'spreading discord' over vaccine safety online |last=Glenza |first=Jessica |date=23 August 2018 |work=The Guardian |access-date=23 August 2018 |name-list-style=vanc}}</ref> The campaign used sophisticated Twitter bots to amplify polarizing pro-vaccine and anti-vaccine messages, containing the hashtag #VaccinateUS, posted by IRA trolls.<ref name=WeaponizedHealthCommunication />

Confidence in vaccines varies over place and time and among different vaccines. The London School of Hygiene & Tropical Medicine's Vaccine Confidence Project in 2016 found that confidence was lower in Europe than in the rest of the world. Refusal of the MMR vaccine has increased in twelve European states since 2010. The project published a report in 2018 assessing vaccine hesitancy among the public in all the 28 EU member states and among general practitioners in ten of them. Younger adults in the survey had less confidence than older people. Confidence had risen in France, Greece, Italy, and Slovenia since 2015 but had fallen in the Czech Republic, Finland, Poland, and Sweden. 36% of the GPs surveyed in the Czech Republic and 25% of those in Slovakia did not agree that the [[Medicine:MMR vaccine|MMR vaccine]] was safe. Most of the GPs did not recommend the seasonal influenza vaccine. Confidence in the population correlated with confidence among GPs.<ref>{{Cite web |url=https://www.vaccineconfidence.org/research/the-state-of-vaccine-confidence-in-the-eu-2018/ |title=The State of Vaccine Confidence in the EU: 2018 |website=Vaccine Confidence Project |publisher=London School of Hygiene & Tropical Medicine |access-date=2 December 2018}}</ref> A study of vaccine-hesitant U.S. college students found that after they interviewed survivors of vaccine-preventable diseases, they were more likely to become pro-vaccine than a control group.<ref>{{Cite journal |last1=Johnson |first1=Deborah K. |last2=Mello |first2=Emily J. |last3=Walker |first3=Trent D. |last4=Hood |first4=Spencer J. |last5=Jensen |first5=Jamie L. |last6=Poole |first6=Brian D. |date=12 May 2019 |title=Combating Vaccine Hesitancy with Vaccine-Preventable Disease Familiarization: An Interview and Curriculum Intervention for College Students |journal=Vaccines |volume=7 |issue=2 |pages=39 |doi=10.3390/vaccines7020039 |pmc=6631173 |pmid=31083632|doi-access=free }}</ref>

Parties opposed to the use of vaccines frequently refer to data obtained from the US [[Medicine:Vaccine Adverse Event Reporting System|Vaccine Adverse Event Reporting System]] (VAERS). This is a database of reports of issues associated with vaccines which has been useful for investigation, but since any claim can be entered into the VAERS, its data is not all reliable. Dubious claims about vaccines against hepatitis B, HPV and other diseases have been propagated based on misuse of data from VAERS.<ref>{{Cite web |url=https://www.csicop.org/si/show/diving_into_the_vaers_dumpster_fake_news_about_vaccine_injuries |title=Diving into the VAERS Dumpster |last=Hall |first=Harriet |website=CSI |date=November 2018 |publisher=Center for Inquiry |access-date=15 December 2018}}</ref>
{{Clear}}

==See also==
*[[Chemistry:Chemophobia|Chemophobia]]
*Measles resurgence in the United States
*Misinformation related to vaccination
*[[Unsolved:Therapeutic nihilism|Therapeutic nihilism]]
*[[Biology:Vaccine shedding|Vaccine shedding]]
*COVID-19 vaccine misinformation and hesitancy

==References==
{{Reflist}}

==Further reading==
{{refbegin}}
*{{Cite book |title=Vaccine: The Debate in Modern America |last=Largent, Mark A. |publisher=Johns Hopkins University Press |year=2012 |isbn=978-1421406077}}
*{{Cite journal |vauthors=Bedford H, Elliman D |date=January 2000 |title=Concerns about immunisation |journal=BMJ |volume=320 |issue=7229 |pages=240–43 |doi=10.1136/bmj.320.7229.240 |pmc=1117437 |pmid=10642238}}
*{{Cite journal |vauthors=Davies P, Chapman S, Leask J |date=July 2002 |title=Antivaccination activists on the world wide web |journal=Archives of Disease in Childhood |volume=87 |issue=1 |pages=22–25 |doi=10.1136/adc.87.1.22 |pmc=1751143 |pmid=12089115}}
*{{Cite journal |vauthors=Richardson PD, Mohammed SF, Mason RG, Steiner M, Kane R |year=2004 |title=Dynamics of platelet interaction with surfaces in steady flow conditions |journal=Transactions of the American Society for Artificial Internal Organs |volume=25 |issue=7473 |pages=147–51 |doi=10.1136/bmj.329.7473.1049 |pmid=524574 |pmc=524574}}
*{{Cite web |url=http://www.pathguy.com/antiimmu.htm |title=The anti-immunization activists: a pattern of deception |last=Friedlander E |year=2007 |access-date=2007-11-13}}
*{{Cite journal |vauthors=Hanratty B, Holt T, Duffell E, Patterson W, Ramsay M, White JM, Jin L, Litton P |date=October 2000 |title=UK measles outbreak in non-immune anthroposophic communities: the implications for the elimination of measles from Europe |journal=Epidemiology and Infection |volume=125 |issue=2 |pages=377–83 |doi=10.1017/S0950268899004525 |pmc=2869610 |pmid=11117961}}
*{{Cite book |title=Your Baby's Best Shot: Why Vaccines Are Safe and Save Lives |last1=Herlihy |first1=Stacy Mintzer |last2=Hagood |first2=E. Allison |last3=Offit |first3=Paul A. |publisher=Rowman & Littlefield Publishers |year=2012 |isbn=978-1442215788 |name-list-style=vanc |author-link3=Paul A. Offit}}
*{{Cite journal |vauthors=Miller CL |date=February 1985 |title=Deaths from measles in England and Wales, 1970–83 |journal=British Medical Journal |volume=290 |issue=6466 |pages=443–44 |doi=10.1136/bmj.290.6466.443 |pmc=1417782 |pmid=3918622}}
*{{Cite book |title=Do Vaccines Cause That?! A Guide for Evaluating Vaccine Safety Concerns |vauthors=Myers MG, Pineda D |publisher=Immunizations for Public Health (i4ph) |year=2008 |isbn=978-0-9769027-1-3 |location=Galveston, TX}}
*{{Cite journal |last=Naono, Atsuko |year=2006 |title=Vaccination Propaganda: The Politics of Communicating Colonial Medicine in Nineteenth-Century Burma |url=https://archive.org/download/VaccinationPropagandaThePoliticsOfCommunicatingColonialMedicineIn/4.1naono.pdf |journal=SOAS Bulletin of Burma Research |volume=4 |issue=1 |pages=30–44}}
*{{Cite book |title=Autism's False Prophets: Bad Science, Risky Medicine, and the Search for a Cure |title-link=Autism's False Prophets: Bad Science, Risky Medicine, and the Search for a Cure |last=Offit, Paul A. |publisher=Columbia University Press |year=2008 |isbn=978-0-231-14636-4 |}}
*{{Cite book |title=Deadly Choices: How the Anti-Vaccine Movement Threatens Us All |last=Offit, Paul A. |publisher=Basic Books |year=2012 |isbn=978-0465029624 |}}
*{{Cite journal |vauthors=Orenstein WA, Hinman AR |date=October 1999 |title=The immunization system in the United States – the role of school immunization laws |journal=Vaccine |volume=17 |issue=Suppl 3 |pages=S19–24 |doi=10.1016/S0264-410X(99)00290-X |pmid=10559531}}
*{{Cite journal |vauthors=Spier RE |date=November 1998 |title=Ethical aspects of vaccines and vaccination |journal=Vaccine |volume=16 |issue=19 |pages=1788–94 |doi=10.1016/S0264-410X(98)00169-8 |pmid=9795382 |pmc=7173252}}
*{{Cite journal |vauthors=Vermeersch E |date=October 1999 |title=Individual rights versus societal duties |journal=Vaccine |volume=17 |issue=Suppl 3 |pages=S14–17 |doi=10.1016/s0264-410x(99)00289-3 |pmid=10627239}}
*{{Cite journal |vauthors=Wolfe RM, Sharp LK, Lipsky MS |date=June 2002 |title=Content and design attributes of antivaccination web sites |journal=JAMA |volume=287 |issue=24 |pages=3245–48 |doi=10.1001/jama.287.24.3245 |pmid=12076221|doi-access=}}
*{{Cite web |url=https://www.who.int/immunization_safety/aefi/immunization_misconceptions/en/ |archive-url=https://web.archive.org/web/20031226120650/http://www.who.int/immunization_safety/aefi/immunization_misconceptions/en/ |url-status=dead |archive-date=December 26, 2003 |title=Six common misconceptions about immunization |date=February 16, 2006 |publisher=World Health Organization |access-date=2006-11-02}}
*Lewandowsky et al. Anti-Vax Psychology Study Report{{Cite magazine |last=Mooney, Chris |date=October 2, 2013 |title=If You Distrust Vaccines, You're More Likely to Think NASA Faked the Moon Landings |url=https://www.motherjones.com/environment/2013/10/vaccine-denial-conspiracy-theories-gmos-climate |magazine=Mother Jones |access-date=2016-02-02}}
*National Academies of Sciences, Engineering, and Medicine 2020. Vaccine Accessand Hesitancy: Part One of a Workshop Series: Proceedings of a Workshop inBrief. Washington, DC: The National Academies Press. https://doi.org/10.17226/25895.
{{refend}}

==External links==
*{{curlie |Society/Issues/Health/Vaccination |Vaccination}}
*{{Cite web |url=https://www.who.int/immunization/en/ |title=Immunizations, vaccines and biologicals |publisher=World Health Organization}}
*{{Cite web |url=https://www.cdc.gov/vaccines/ |title=Vaccines & immunizations |date=2018-09-04 |publisher=Centers for Disease Control and Prevention}}
*{{Cite serial |series=Frontline |title=The Vaccine War |url=https://www.pbs.org/wgbh/pages/frontline/vaccines/ |network=PBS |date=April 27, 2010}}
*{{cite web |author1=Institute of Global Health Innovation |title=Global attitudes towards a COVID-19 vaccine |url=https://www.imperial.ac.uk/media/imperial-college/institute-of-global-health-innovation/GlobalVaccineInsights_ICL-YouGov-Covid-19-Behaviour-Tracker_20210520_v2.pdf |website=Imperial College London |publisher=Covid Data Hub |date=May 2021}}
*{{cite web |title=Vaccine Education Center |url=https://www.chop.edu/centers-programs/vaccine-education-center |website=Children's Hospital of Philadelphia |date=November 19, 2014 }}

{{Vaccines}}

{{DEFAULTSORT:Vaccine hesitancy}}
[[Category:Autism pseudoscience]]

{{Sourceattribution|Vaccine hesitancy}}