CDC’s New Autism Webpage Distorts Science and Rejects Decades of Evidence on Vaccine Safety

NEW YORK, NY (November 20, 2025) We are appalled to find that the content on the CDC webpage “Autism and Vaccines” has been changed and distorted, and is now filled with anti-vaccine rhetoric and outright lies about vaccines and autism. The CDC’s previous science and evidence-based website has been replaced with misinformation and now actually contradicts the best available science. The new statement on the site that says ““vaccines do not cause autism” is not an evidence-based claim” shows a lack of understanding of the term “evidence”. 

The science is clear that vaccines do not cause autism. No environmental factor has been better studied as a potential cause of autism than vaccines. This includes vaccine ingredients as well as the body’s response to vaccines. All this research has determined that there is no link between autism and vaccines. 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. For example, differences in brain structure can be seen as early as the second trimester of gestation. 

“The facts don’t change because the administration does”, said Alison Singer, president of the Autism Science Foundation. At this point it’s not about doing more studies; it’s about being willing to accept what the existing study data clearly show. You can’t just ignore data because it doesn’t confirm your beliefs, but that’s what the administration is doing.”

“The CDC has always been a trustworthy source of scientifically-backed information but it appears this is no longer the case”, added Singer. “Spreading this misinformation will needlessly cause fear in parents of young children who may not be aware of the mountains of data exonerating vaccines as a cause of autism and who may withhold vaccines in response to this misinformation, putting their children at risk to contract and potentially die from vaccine preventable diseases.”  

“We were right back in the 1990’s to study whether vaccines caused autism,” added ASF Chief Science Officer Dr. Alycia Halladay “because children were receiving more vaccinations and more children were being diagnosed with autism. But that work is done. We have dozens and 

dozens of studies, including studies of infants, and they are clear and conclusive. Vaccines don’t cause autism. If we want to find the true causes of autism we need to ask new questions”

Here’s what we know about the causes of autism:

  • An overwhelming amount of evidence points to genetics. In about 15-20% of autism cases, one genetic variant can explain autism features. In other cases, there may be multiple genetic mutations interacting to cause autism.
  • Autism runs in families. Siblings of a child with autism have a fifteen times greater likelihood of diagnosis, and nieces and nephews of a person with autism have a 3 times greater risk.
  • Scientists are also examining how environmental factors work independently in conjunction with genes to cause autism. Environmental factors associated with autism include:
    • Being born prematurely: Children born prematurely or with extremely low birthweight have a higher probability of autism. 
    • Having an older parent or parents: Higher age at conception of either the mother or father or both adds to likelihood of an ASD diagnosis. 
    • Illness during pregnancy: Illness and fever during pregnancy can increase the likelihood that a child will be diagnosed with autism. This includes illnesses like rubella, pertussis, Covid-19, RSV, and influenza, which can be prevented by vaccines. 
    • Exposures during pregnancy:  Exposure to some anti-epileptic drugs as well as high levels of air pollution during pregnancy have been associated with autism in offspring.
    • Presence of maternal metabolic disorders:  Disorders like gestational diabetes may lead to later diagnosis of autism in offspring.

About the Autism Science Foundation
The Autism Science Foundation (ASF) is a 501(c)(3) public charity. Its mission is to fund breakthrough research that will improve the lives of people with autism. To learn more about the Autism Science Foundation visit www.autismsciencefoundation.org.

ASF Media Contact:
C.J. Volpe
cvolpe@autismsciencefoundation.org