Last week we debunked the myth about vaccines causing autism due to mercury, you can read the post here. This week, we approach yet another very extended myth about the link between vaccines and autism.
The story of how vaccines came to be questioned as a cause of autism dates back to the 1990’s, following two articles that appeared in the British Medical Journal, The Lancet. In 1995, it was published that individuals who had been vaccinated with the measles-mumps-rubella vaccine (MMR) were more likely to have bowel disease than individuals who had not received MMR [1]. One of these researchers was gastroenterologist Andrew Wakefield, who further published a possible link between the vaccine and bowel disease in 1998.
Wakefield speculated that persistent infection with an attenuated (weakened) live virus vaccine (for more information about the different types of vaccines, you can read here) caused disruption of the intestinal tissue, leading to bowel disease and neuropsychiatric disease (specifically, autism) [2]. The theory that links bowel disease and autism is known as the opioid excess theory, which postulates that autism is the result of a metabolic disorder caused by an abnormally permeable membrane of the intestine [3].
The truth
Although Wakefield’s research was met with initial skepticism among scientific and medical professionals, it attracted considerable attention. News of the supposed connection between autism and the MMR vaccine travelled quickly and alarmed many parents throughout the world [4], resulting in an instant decline in vaccine numbers in both Britain and the United States. The possible connection between the MMR vaccine and bowel disease or autism has been subject to exhaustive research since the publication of the paper, and there has been absolutely no link found.
In 2004, the then-editor of The Lancet, Dr. Richard Horton, revealed ethical violations, fraud and grave flaws in the research published by Wakefield and in 2010, the paper was retracted from the journal. Three months after the retraction, in May 2010, Britain’s General Medical Council banned Wakefield from practising medicine in Britain and revoked his licence, stating that he had shown “callous disregard” for children in the course of his research [5].
Since the criteria for diagnosing autism has become more precise, professionals have been better at diagnosing children in the first years of their life [5]. Because of this, and the fact that children receive their first dose of the MMR vaccine within the first two years of their life, people believe that the MMR vaccine is linked to autism.
Despite the fact that numerous studies have found no evidence to support the notion that vaccines cause autism or any other chronic illness, this myth, and the previous one, are still being used as arguments against vaccination. This causes parents to be increasingly hesitant when it comes to having their children vaccinated, since a parent’s first instinct is to protect their child. However, scientists have done a very good job at conducting remarkable research to show that the causes of autism are varied and include mostly genetic and environmental factors, rather than vaccines. Furthermore, thanks to said vaccinations, infant mortality and disability have been significantly reduced [6].
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Written by: Phaedra
Edited by: María and Natasha
BioDecoded is a volunteer group committed to sharing accurate scientific information. For more information about vaccines and their safety profile, please see previous posts or consult with your personal physician. If you have any questions about this topic, please comment or send them to our email.
References:
Thompson, N. et al. (1995) “Is measles vaccination a risk factor for inflammatory bowel disease?”, The Lancet, 345(8957), pp. 1071-1074. Available at: https://pubmed.ncbi.nlm.nih.gov/7715338/
Wakefield, A. et al. (1998) “RETRACTED: Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children”, The Lancet, 351(9103), pp. 637-641. Available at: https://www.thelancet.com/journals/lancet/article/PIIS0140673697110960/fulltext
Millward, C. et al. (2008) “Gluten- and casein-free diets for autistic spectrum disorder”, Cochrane Database of Systematic Reviews. Available at: https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD003498.pub3/full
Jang, S. et al. (2017) “From Social Media to Mainstream News: The Information Flow of the Vaccine-Autism Controversy in the US, Canada, and the UK”, Health Communication, 34(1), pp. 110-117. Available at: https://pubmed.ncbi.nlm.nih.gov/29028371/
Do Vaccines Cause Autism? | History of Vaccines. The College of Physicians of Philadelphia(2016). Available at: https://www.historyofvaccines.org/index.php/content/articles/do-vaccines-cause-autism (Accessed: 17 December 2021).
“Vaccines Reduce Childhood Mortality”. Nature Medicine, 2021. Available at: https://www.nature.com/articles/d41591-021-00014-8 (Accessed 17 Dec 2021).
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