The CDC's vaccine-and-autism web page was edited to say the claim "Vaccines do not cause autism" is "not an evidence-based claim," a change that multiple CDC officials say was ordered by HHS political appointees without consultation with agency scientists. The revision conflicts with decades of research — including numerous large studies — that find no causal link between vaccines and autism. Public-health leaders and autism advocacy groups say the edit undermines scientific credibility and could reduce vaccination rates, while HHS describes it as an update aimed at transparency and further research.
CDC Website Edit Sparks Controversy After HHS-Appointed Staff Add Questioning Language on Vaccines and Autism
The CDC's vaccine-and-autism web page was edited to say the claim "Vaccines do not cause autism" is "not an evidence-based claim," a change that multiple CDC officials say was ordered by HHS political appointees without consultation with agency scientists. The revision conflicts with decades of research — including numerous large studies — that find no causal link between vaccines and autism. Public-health leaders and autism advocacy groups say the edit undermines scientific credibility and could reduce vaccination rates, while HHS describes it as an update aimed at transparency and further research.
01:24 AM, 11/21/2025Health
Multiple Centers for Disease Control and Prevention (CDC) officials say a page on the agency's website was altered to include language that questions the established statement that vaccines do not cause autism. The change — which replaces previous wording that said "no links have been found between any vaccine ingredients and Autism spectrum disorder" with the line that "'Vaccines do not cause autism' is not an evidence-based claim" — has drawn sharp criticism from public-health leaders and autism advocacy groups.
According to CDC staff familiar with the edits, political appointees at the Department of Health and Human Services (HHS) directed the change without consulting the agency's subject-matter experts. Earlier revisions to pages on autism and vaccination were typically made only after review by experts at the CDC's National Center on Birth Defects and Developmental Disabilities and the National Center for Immunization and Respiratory Diseases.
Why the change is controversial
The new wording also asserts that studies suggesting a link between vaccines and autism "have been ignored by health authorities," a characterization autism researchers and advocacy groups call misleading. The Autism Science Foundation called the edit "misinformation" that contradicts decades of research showing no causal link between routine childhood vaccines and autism.
Public-health organizations point to a large body of evidence: the now-discredited 1998 study that first linked the MMR vaccine to autism was found to be fraudulent and retracted, and subsequent independent research — including dozens of high-quality studies across multiple countries and millions of people — has found no association between vaccines and autism diagnoses.
"There is overwhelming evidence that vaccines do not cause autism," said Dr. Mandy Cohen, a former CDC director, warning that the change undermines scientific credibility and could reduce vaccination rates, leaving children vulnerable to preventable diseases.
Dr. Sean O'Leary, chair of the American Academy of Pediatrics' Committee on Infectious Diseases, said the edit risks frightening parents and further stigmatizing people with autism. Advocacy leaders stressed that while it's difficult to "prove a negative," the cumulative research has repeatedly exonerated vaccines as a cause.
HHS response and ongoing disputes
HHS communications director Andrew Nixon described the revision as an update intended to reflect a commitment to transparency and further research. In a statement, he said the page explains that current studies "have not definitively ruled out potential associations" and that HHS wants a definitive answer.
Autism advocacy groups and many scientists dispute that characterization. They emphasize the scale and quality of existing studies and warn that presenting long-settled science as unsettled can erode public trust and jeopardize immunization coverage.
The CDC page still shows a subhead reading "Vaccines do not cause autism" with an asterisk; the page notes the header remains in place because of an agreement with Sen. Bill Cassidy. Cassidy — a physician who chairs the Senate Health, Education, Labor, and Pensions Committee — publicly reiterated that vaccines for measles, polio, hepatitis B and other childhood diseases are safe and effective and will not cause autism.
Critics also point to other recent moves that they say sideline scientists: the appointment of a vaccine skeptic to oversee a new research effort and reports that career scientists were bypassed in messaging decisions. Former CDC officials warn that removing scientists from review processes risks replacing data-driven communication with rhetoric that could harm families.
Other federal health pages about autism and vaccines had not been altered as of the latest updates. Public-health leaders say they will continue to promote the scientific evidence on vaccine safety while urging careful, independent research into the biological and environmental factors that may contribute to autism.