Vaccines and autism
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Extensive investigation into vaccines and autism[1] has shown that there is no relationship between the two, causal or otherwise,[1][2][3] and that vaccine ingredients do not cause autism.[4] Vaccinologist Peter Hotez researched the growth of the false claim and concluded that its spread originated with Andrew Wakefield's fraudulent 1998 paper, with no prior paper supporting a link.[5]
Despite the scientific consensus for the absence of a relationship[1][2] and the retracted paper, the anti-vaccination movement at large continues to promote theories linking the two.[6] 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."[7]
Claimed mechanisms
The claimed mechanisms have changed over time, in response to evidence refuting each in turn.[8]
Vaccine-derived measles virus
The idea of a link between the
Wakefield's primary claim was that he had isolated evidence of vaccine-strain measles virus RNA in the intestines of autistic children, leading to a condition he termed
The
In 2009,
On 12 February 2009, a special court convened in the United States to review claims under its
Thiomersal
Thiomersal is an 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.[18] Thiomersal contains ethylmercury, a mercury compound which is related to, but significantly less toxic than, the neurotoxic pollutant methylmercury. Despite decades of safe use,[19] public campaigns prompted the CDC and the American Academy of Pediatrics (AAP) to request vaccine makers to remove thiomersal from vaccines as quickly as possible on the precautionary principle. Thiomersal is now absent from all common United States and European Union vaccines, except for some preparations of influenza vaccine.[20] (Trace amounts remain in some vaccines due to production processes, at an approximate maximum of 1 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 World Health Organization [WHO].)[21][22] The action engendered concern thiomersal could have been responsible for autism.[20]
The idea that thiomersal was a cause or trigger for autism is now considered disproven, as incidence rates for autism increased steadily even after thiomersal was removed from childhood vaccines.[8] There is no accepted scientific evidence that exposure to thiomersal is a factor in causing autism.[23]
Under the U.S.
Vaccine overload
Following the belief that individual vaccines caused autism was the idea of vaccine overload, which claims that too many vaccines at once may overwhelm or weaken a child's immune system and lead to adverse effects.[29] Vaccine overload became popular after the Vaccine Injury Compensation Program in the United States accepted the case of nine-year-old Hannah Poling. Poling had encephalopathy, putting her on the autism spectrum disorder, which was believed to have worsened after getting multiple vaccines at nineteen months old.[8] There have been multiple cases reported similar to this one, which led to the belief that vaccine overload caused autism. However, scientific studies show that vaccines do not overwhelm the immune system.[8] In fact, conservative estimates predict that the immune system can respond to thousands of viruses simultaneously.[8] It is known that vaccines constitute only a tiny fraction of the pathogens already naturally encountered by a child in a typical year.[8] Common fevers and middle ear infections pose a much greater challenge to the immune system than vaccines do.[30] Other scientific findings support the idea that vaccinations, and even multiple concurrent vaccinations, do not weaken the immune system[8] or compromise overall immunity[31] and evidence that autism has any immune-mediated pathophysiology has still not been found.[8]
Aluminium salts
As mercury compounds in vaccines have been definitively ruled out as a cause of autism, some anti-vaccine activists propose
Celebrity involvement
Some celebrities have spoken out on their views that autism is related to vaccination, including: Jenny McCarthy, Kristin Cavallari,[38] Toni Braxton,[38] Robert De Niro,[39] Jim Carrey,[40] Bill Maher,[41] and Pete Evans.[42]
McCarthy, one of the most outspoken celebrities on the topic, has said her son Evan's autism diagnosis was a result of the MMR vaccine.[43] She authored Louder than Words: A Mother's Journey in Healing Autism and co-authored Healing and Preventing Autism.[44] She also founded Generation Rescue, an organisation which provides resources for families affected by autism.[45]
In a September 2015 U.S. presidential debate, Republican Party candidate and future United States President Donald Trump stated he knew of a 2-year-old child who had recently received a combined vaccine, developed a fever, and subsequently autism.[46]
Robert F. Kennedy, Jr. is one of the most notable proponents of the anti-vaccine movement. Kennedy published the book Thimerosal: Let the Science Speak: The Evidence Supporting the Immediate Removal of Mercury--A Known Neurotoxin--From Vaccines.[47] He is also chairman of the board of Children's Health Defense, a group and website widely known for its anti-vaccination stance.[48]
Public opinion
In December 2020, a poll of 1,115 U.S. adults found 12% of respondents believed there is evidence vaccinations cause autism; 51% believed there is no evidence; and 37% did not know.[49]
References
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- ^ S2CID 40669829.
- ^ Boseley S (February 2, 2010). "Lancet retracts 'utterly false' MMR paper". The Guardian. Retrieved February 2, 2010.
- ^ "Vaccines Do Not Cause Autism Concerns". Centers for Disease Control and Prevention. 2018-12-12. Retrieved 2019-02-07.
- OCLC 1020295646.)
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: CS1 maint: multiple names: authors list (link - ^ Cummins, Eleanor (February 2019). "How autism myths came to fuel anti-vaccination movements A timeline leading to the 2019 measles outbreaks". Popular Science.
- ^ Foster CA, Ortiz SM (February 2016). "Vaccines, Autism, and the Promotion of Irrelevant Research: A Science-Pseudoscience Analysis". Skeptical Inquirer. 41 (3): 44–48. Archived from the original on 2018-10-06. Retrieved 6 October 2018.
- ^ PMID 19128068.
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- ^ "Concerns about autism". Centers for Disease Control and Prevention. 2010-01-15.
- ^ PMID 20669467.
- ^ MMR Fact Sheet Archived June 15, 2007, at the Wayback Machine, from the United Kingdom National Health Service. Retrieved June 13, 2007.
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- ^ Deer B (2009-02-08). "MMR doctor Andrew Wakefield fixed data on autism". Sunday Times. Retrieved 2009-02-09.
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- ^ Vaccine court and autism:
- "Vaccine didn't cause autism, court rules". CNN. 2009-02-12. Retrieved 2009-02-12.
- Theresa Cedillo and Michael Cedillo, as parents and natural guardians of Michelle Cedillo vs. Secretary of Health and Human Services, 98-916V (United States Court of Federal Claims 2009-02-12).
- PMID 18172138.
- ^ "Thimerosal in Vaccines". Centers for Disease Control and Prevention. 2019-01-24. Retrieved 2019-02-07.
- ^ PMID 17898096.
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- ^ "Vaccine Safety & Availability – Thimerosal in Vaccines". FDA. 5 April 2019.
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- ^ "Vaccine Safety & Availability - Thimerosal in Vaccines". www.fda.gov. Retrieved 2016-02-08.
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- ^ "UPDATE 1-US court rules again against vaccine-autism claims". Reuters. 2010-03-12. Retrieved 2019-02-07.
- ^ Salzberg, Steven. "Vaccine Court Ruling: Thimerosal Does Not Cause Autism". Retrieved 2019-02-07.
- S2CID 27129014. Retrieved 2019-02-07.
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- ^ Immune challenges:
- Murphy TF (June 1996). "Branhamella catarrhalis: epidemiology, surface antigenic structure, and immune response". Microbiological Reviews. 60 (2): 267–79. PMID 8801433.
- Sloyer JL, Howie VM, Ploussard JH, Ammann AJ, Austrian R, Johnston RB (June 1974). "Immune response to acute otitis media in children. I. Serotypes isolated and serum and middle ear fluid antibody in pneumococcal otitis media". Infection and Immunity. 9 (6): 1028–32. PMID 4151506.
- Murphy TF (June 1996). "Branhamella catarrhalis: epidemiology, surface antigenic structure, and immune response". Microbiological Reviews. 60 (2): 267–79.
- ^ Vaccine burden:
- Miller E, Andrews N, Waight P, Taylor B (March 2003). "Bacterial infections, immune overload, and MMR vaccine. Measles, mumps, and rubella". Archives of Disease in Childhood. 88 (3): 222–3. PMID 12598383.
- Hviid A, Wohlfahrt J, Stellfeld M, Melbye M (August 2005). "Childhood vaccination and nontargeted infectious disease hospitalization". JAMA. 294 (6): 699–705. PMID 16091572.
- Miller E, Andrews N, Waight P, Taylor B (March 2003). "Bacterial infections, immune overload, and MMR vaccine. Measles, mumps, and rubella". Archives of Disease in Childhood. 88 (3): 222–3.
- ^ Nerd, Gid M.-K; Health (2017-12-05). "Vaccines Don't Cause Autism". Retrieved 2019-02-07.
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- ^ "Vaccines, Autism, and Retraction". 2017-05-10. Archived from the original on 2019-10-19. Retrieved 2019-02-07.
- ^ "Dwoskin Foundation – Science-Based Medicine". Retrieved 2019-02-07.
- ^ "UBC stands behind vaccine studies discredited by WHO". 2015-03-04. Retrieved 2019-02-07.
- ^ a b "Kristin Cavallari Defends Anti-Vaccine Stance". The Huffington Post. 19 March 2014. Retrieved 2016-02-08.
- ^ "Robert De Niro defends discredited idea linking vaccines to autism". Stat. 13 April 2016. Retrieved 2016-04-13.
- ^ Kluger J (2 July 2015). "Jim Carrey, Please Shut Up About Vaccines". TIME.com. Retrieved 2016-02-08.
- ^ Tenbarge, Kat. "Bill Maher agreed with a controversial doctor, repeating a debunked theory that it was 'realistic' that vaccines have caused autism in children". Insider. Retrieved 2019-11-02.
- ^ "Bent Spoon to celebrity chef Pete Evans – Australian Skeptics Inc". 2019-03-28. Archived from the original on 2019-03-28. Retrieved 2021-01-26.
- ^ "Jenny McCarthy: "We're Not An Anti-Vaccine Movement ... We're Pro-Safe Vaccine"". FRONTLINE. Retrieved 2016-02-08.
- ISSN 0040-781X. Retrieved 2016-02-08.
- ^ "About Generation Rescue » Generation Rescue | Jenny McCarthy's Autism Organization". www.generationrescue.org. Retrieved 2016-02-08.
- ^ "Medical experts condemn Donald Trump for debate comments suggesting vaccines can cause autism". NY Daily News. 18 September 2015. Retrieved 2016-02-08.
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- ^ Even If It's 'Bonkers,' Poll Finds Many Believe QAnon And Other Conspiracy Theories