Facebook Twitter Tumblr Close Skip to main content
A Project of The Annenberg Public Policy Center

False Claim About Cause of Autism Highlighted on Pennsylvania Senate Panel

This article is available in both English and Español

SciCheck Digest

Studies have found the rate of autism is the same in vaccinated and unvaccinated children. But the false claim that vaccines are associated with the disorder persists. A prominent spreader of COVID-19 misinformation wrongly told legislators in Pennsylvania that autism is virtually nonexistent among the unvaccinated, citing the Amish population.

Full Story

Evidence has shown that the measles, mumps and rubella vaccine commonly given to children isn’t related to the development of autism.

Rather, autism is understood to be caused by a combination of factors — some genetic and some environmental — although the disorder is still being studied. The environmental factors that can increase the risk of autism include advanced age of either parent and complications during birth, according to recent research. Vaccination is not a contributing factor.

But the false claim about vaccination and autism has been circulating since 1998, when a since-retracted paper wrongly suggested the MMR vaccine was linked to autism. Data presented in the paper were later found to be fabricated. The General Medical Council in the United Kingdom stripped the lead author of his ability to practice medicine for his dishonesty and irresponsibility in the paper. But the baseless claim has remained.

It was recently repeated on a “medical freedom panel” hosted by Doug Mastriano — a Pennsylvania state senator who has made dubious claims about COVID-19 vaccines. Among those on his June 9 panel was Steve Kirsch, an entrepreneur who is not a doctor or medical expert.

Kirsch referenced the well-worn falsehood linking the MMR vaccine to autism, but broadened it to suggest that vaccines, generally, cause a host of ailments as well as gender dysphoria and homosexuality.

He told legislators, “The Amish are a perfect example of a large group of people who are largely unvaccinated and there’s no autism — we can’t find an autistic kid who was unvaccinated. It’s very, very rare. In the Amish community — very, very rare. You won’t find transsexuals. You won’t find homosexuals. You won’t find kids with ADD, with autoimmune disease, with PANDAS/PANS, with epilepsy. You just don’t find any of these chronic diseases in the Amish.”

Clips from this portion of the panel are now circulating on social media.

Since Kirsch has also repeated the specific claim about MMR vaccines, we’ll first address his claim that “we can’t find an autistic kid who was unvaccinated.”

MMR Vaccine and Autism

Studies have shown that the rate of autism present in children who were vaccinated against measles, mumps and rubella compared with those who were never vaccinated is the same.

A 2019 paper found that children who were given the MMR vaccine were diagnosed with autism at about the same rate as those who weren’t.

That study “strongly supports that MMR vaccination does not increase the risk for autism, does not trigger autism in susceptible children, and is not associated with clustering of autism cases after vaccination,” its authors wrote.

As early as 2004, there was already evidence that vaccines did not cause autism. An Immunization Safety Review Committee’s report published that year by the National Academy of Sciences concluded “that the body of epidemiological evidence favors rejection of a causal relationship between the MMR vaccine and autism.”

Many studies since then have also shown similar findings.

So, Kirsch need only look to those studies to find examples of unvaccinated children who developed autism. His suggestion that the disorder is less common among unvaccinated children is wrong.

Vaccines Among the Amish

As for Kirsch’s claim that in addition to autism, gender dysphoria, homosexuality, attention-deficit/hyperactivity disorder, autoimmune diseases, Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcal Infections (PANDAS) and Pediatric Acute-onset Neuropsychiatric Syndrome (PANS), and epilepsy are virtually nonexistent among the Amish because they are unvaccinated — that’s not right, either.

First of all, Kirsch makes the unsupported assumption that the Amish community is “largely unvaccinated.”

It’s hard to know what the vaccination rate is among the Amish community as a whole because there is no data available on that. But research on some Amish groups has shown that children are vaccinated. One paper from 2017 that studied an Amish community in northern Ohio found that 98% of the parents surveyed had immunized their children in whole or in part. Another paper from 2011 found that, of the parents surveyed, 85% had vaccinated at least some of their children.

Also, it’s worth noting that a 2010 conference paper studied autism among the Amish, specifically, which shows that the disorder does exist within that community. The paper said, “Preliminary data have identified the presence of ASD in the Amish community at a rate of approximately 1 in 271 children using standard ASD screening and diagnostic tools although some modifications may be in order.” That rate was lower than the general population, the paper noted, but that could be due to a variety of factors, including differences in how caregivers answered screening questions or genetic differences. Even if autism is less common among the Amish, there is no evidence that it has anything to do with vaccination — and indeed, numerous studies contradict such an interpretation.

Second, on the suggestion that vaccines cause people to become “transsexuals,” as Kirsch said — we’ve written before about the similar false claim that standard childhood vaccination causes gender dysphoria, which is the distress felt by some transgender individuals since their sex assigned at birth doesn’t match their gender identity.

There’s also no evidence to support the claim that vaccination is responsible for causing heterosexuality, homosexuality or bisexuality, either. But Kirsch isn’t the first to make the claim. QAnon conspiracy theorists in 2021 spread the claim that vaccines could make children homosexual after an Iranian cleric with a history of spreading fake COVID-19 cures — Abbas Tabrizian — posted about it on Telegram.

Kirsch’s suggestion that various ailments are caused by vaccines is similarly unsupported by evidence.

For example, his suggestion that “ADD” — or attention-deficit disorder, which is the old name for what is now called attention-deficit/hyperactivity disorder, ADHD — is a result of vaccines is also wrong.

There have been three large studies that have examined the risk that vaccines could cause ADHD. In particular, two of those studies looked at the effect of a preservative called thimerosal. Anti-vaccine campaigners have pointed to thimerosal as the trigger for various diseases — including both autism and ADHD — even though it hasn’t been included in childhood vaccines since 2001, according to the Centers for Disease Control and Prevention.

All three of those studies found that there was no association between vaccination and ADHD.

“Therefore, parents can be reassured that vaccines do not cause ADHD or related conditions,” the Children’s Hospital of Philadelphia wrote in a post explaining the issue.

Kirsch didn’t offer any support for his claims during his panel appearance, and we were unable to find any research suggesting that vaccines are responsible for any of the conditions that he listed.

Editor’s note: SciCheck’s articles providing accurate health information and correcting health misinformation are made possible by a grant from the Robert Wood Johnson Foundation. The foundation has no control over FactCheck.org’s editorial decisions, and the views expressed in our articles do not necessarily reflect the views of the foundation.


American Academy of Pediatrics. “Vaccine Safety: Examine the Evidence.” Updated 6 Sep 2022.

Centers for Disease Control and Prevention. “Measles, Mumps, and Rubella (MMR) Vaccination: What Everyone Should Know.” Updated 26 Jan 2021.

Centers for Disease Control and Prevention. “What is Autism Spectrum Disorder?” Updated 9 Dec 2022.

Autism Speaks. “What Causes Autism?” Accessed 13 Jul 2023.

Jain, Anjali, et al. “Autism Occurrence by MMR Vaccine Status Among US Children With Older Siblings With and Without Autism.” JAMA. 21 Apr 2015.

Institute of Medicine. Immunization Safety Review: Vaccines and Autism. National Academies Press. 2004.

Centers for Disease Control and Prevention. “Autism and Vaccines.” Updated 1 Dec 2021.

Taylor, Luke E., Amy L. Swerdfeger and Guy D. Eslick. “Vaccines are not associated with autism: an evidence-based meta-analysis of case-control and cohort studies.” Vaccine. 17 Jun 2014.

Jain, Anjali, et al. “Autism Occurrence by MMR Vaccine Status Among US Children With Older Siblings With and Without Autism.” JAMA. 21 Apr 2015.

Children’s Hospital of Philadelphia. “Vaccines and Autism.” Updated 7 May 2018.

Cleveland Clinic. “Does Autism Run in Families?” 28 Apr 2023.

Hviid, Anders, et al. “Measles, Mumps, Rubella Vaccination and Autism.” Annals of Internal Medicine. 16 Apr 2019.

Kettunen, Christine, John Nemecek and Olivia Wenger. “Evaluation of low immunization coverage among the Amish population in rural Ohio.” American Journal of Infection Control. 1 Jun 2017.

Wenger, Olivia. “Underimmunization in Ohio’s Amish: Parental Fears Are a Greater Obstacle Than Access to Care.” Pediatrics. 1 Jul 2011.

Hale Spencer, Saranac. “Posts Make False Claim About Cause of Gender Dysphoria.” FactCheck.org. 22 Jun 2023.

Greenspan, Rachel E. and Quispe López. “The latest viral COVID-19 conspiracy theory boosted by QAnon falsely claims vaccines turn children gay or trans.” Insider. 12 Feb 2021.

Faghihi, Rohollah. “A cleric’s cure for coronavirus becomes butt of jokes in Iran.” Al-Monitor. 10 Mar 2020.

Children’s Hospital of Philadelphia. “Vaccines and ADHD.” 21 May 2020.

Centers for Disease Control and Prevention. “Thimerosal FAQs.” Updated 19 Aug 2020.