The following is a personal essay that reflects the opinion of its author.
November 24, 2025
U.S. Health and Human Services Secretary Robert F. Kennedy, Jr., has never attended medical school. He has no prior experience in formulating public health policy and no training in neurodevelopmental disorders. His opinions on the causes of autism have no basis in science and have drawn widespread criticism from medical and public health experts for their inaccuracies.
And Kennedy was wrong last week to order the U.S. Centers for Disease Control and Prevention (CDC) to change its website guidance on autism and vaccines. It now claims, without credible evidence, that “scientific studies have not ruled out the possibility that infant vaccines contribute to the development of autism,” an alarming reversal of the CDC’s longstanding position based on decades of research.
The American Academy of Pediatrics, along with 40 other medical, health, and patient advocate groups, responded immediately with a letter chastising the CDC for “promoting the outdated, disproven idea that vaccines cause autism.” For the last 25 years, dozens of rigorous, large-scale studies have found no evidence of an association between childhood vaccines and autism.1, 2, 3 These include a large-scale Danish study, published in the New England Journal of Medicine, which involved more than 537,000 participants (all the children born in Denmark over a seven-year period)4 as well as a meta-analysis involving cohort and case-control studies and more than 1.2 million children.5
[News: Anti-Vaccine Activist David Geier (Not a Doctor) Heads HHS Study on Vaccines and Autism Despite Past Censure]
“There is no link between autism and vaccines,” wrote the Autism Science Foundation on its website last Thursday. “This is consistent across multiple studies, repeated in different countries around the world, with different individuals, at different ages including infancy, and using different model systems. In addition, we know that some biological features of autism can be found prenatally, before any vaccines are administered.”
We know that autism is a highly heritable neurodevelopmental disorder. More than 100 genes have been associated with the condition, but experts agree that genetics and environmental factors likely both contribute. Controlling for a host of potentially confounding factors — including a high comorbidity rate with ADHD6, 7 — is critical in uncovering causes of autism, and it is difficult to accomplish.
Meanwhile, untrained and unqualified individuals continue to mistake association with causality when reviewing research studies on autism. For example, President Donald Trump recently claimed that a mother’s Tylenol use in pregnancy causes autism in her offspring, citing a study, co-authored by a Harvard epidemiologist, that found a small association between use of acetaminophen during pregnancy and risk of autism in children. This association, however, was not shown to be causal, a fact explicitly stated by the lead author of the review, Diddier Prada, M.D., Ph.D., assistant professor at the Icahn School of Medicine at Mount Sinai.
“We show that acetaminophen is associated with a higher risk, but not causing it. Those are very different things,” Prada said in an interview with The Washington Post.
[Tylenol and Autism Are Not Causally Linked, Researchers Confirm]
These false claims about autism, published on the CDC website and broadcast at White House press conferences, have an immediate and profoundly negative impact on autistic people and their loved ones. The damage being done is not theoretical. It is real, it is measurable, and our readers are telling us about it right now. Here are some of their stories.
“Both my kids, 14 and 16, are autistic. My daughter came home from school crying shortly after the absurd proclamation. She was insistent that I have all references to autism and ADHD stricken from her school and medical records. The more she cried and talked, the clearer the picture became. She was worried that the Trump administration was creating a list of kids with autism, like her and her brother, so they could be rounded up and put into concentration camps. It took a couple of normalizing hours of conversation for her to calm down. As a parent, when you need to hold your 16-year-old until they stop quaking because of something said by the leader of our country, I get closer to the decision that our family needs to leave the U.S. While I consoled my daughter, I went through the gamut of emotions with anger and fear the predominant ones.”
“We live in Ireland, and even here my autistic child was affected. He asked me, as his mother, ‘Did you do this to me? Did you take a drug that caused my autism?’ He was emotionally dysregulated for days, and very angry toward me as everyone in school was discussing it.”
“My 8-year-old autistic son was watching a news story about the Tylenol-autism claims. He looked at me and said, ‘Wait, I’m autistic. Do I have a disease?’ I affirmed him the same way I always do when he struggles with one of his diagnoses, telling him he is a gift from God to us.”
“My son did have questions, as he is 14, and we didn’t get the diagnosis until he was 13. I felt relieved that I didn’t take Tylenol with his pregnancy, and I did with my other two pregnancies. The other two children are not diagnosed with ASD. I don’t think that the statements made by Kennedy and Trump are sound, but that speaks to the fact that mother shaming still exists when children have disabilities. I am a school counselor and I know better, and it is disheartening to think this still goes on. My son was happy I didn’t take Tylenol, however, he was open to me explaining how studies and research works.”
“Our child is a voracious consumer of science and political videos, plus the autistic kids at her school have a loosely connected network for mutual support. They are smart kids. They just laughed at the stupidity of the pronouncement.”
“This is my AuDHD daughter’s course of study, so she understands the flawed conflation of causation and correlation. It has been more difficult to speak with relatives about it, especially those who are taking this information at face value. Mostly, I have given up trying to change their minds, but am more vocal with the younger relatives who may become pregnant or have a significant other who may become pregnant on the importance of treating high fever during pregnancy.”
“We’ve had very animated conversations about this. We are both outraged by this and find it difficult to fathom how someone running a country can say such wildly inaccurate things without any evidence.”
Anni Layne Rodgers is General Manager at ADDitude.
View Article Sources
1Uchiyama T, Kurosawa M, Inaba Y. MMR-vaccine and regression in autism spectrum disorders: negative results presente from Japan. J Autism Dev Disord 2007;37:210-217.
2Jain A, Marshall J, Buikema A, et al. Autism occurrence by MMR vaccine status among US children with older siblings with and without autism. JAMA 2015;313(15):1534-1540.
3Hviid A, Hansen JV, Frisch M, Melbye M. Measles, mumps, rubella vaccination and autism. Ann Int Med 2019
4Madsen KM, Hviid A, Vestergaard M, et al. A population-based study of measles, mumps, and rubella vaccination and autism. N Engl J Med 2002;347(19):1477-1482.
5Taylor LE, Swerdfeger AL, Eslick GD. Vaccines are not associated with autism: an evidence-based meta-analysis of case-control and cohort studies. Vaccine 2014;32:3623-3629.
6Hours C, Recasens C, Baleyte JM. ASD and ADHD Comorbidity: What Are We Talking About? Front Psychiatry. 2022 Feb 28;13:837424. doi: 10.3389/fpsyt.2022.837424. PMID: 35295773; PMCID: PMC8918663.
7Ying Rong, Chang-Jiang Yang, Ye Jin, Yue Wang, Prevalence of attention-deficit/hyperactivity disorder in individuals with autism spectrum disorder: A meta-analysis. Research in Autism Spectrum Disorders. 2021 May 83: 101759. ISSN 1750-9467, https://doi.org/10.1016/j.rasd.2021.101759