The U.S. Centers for Disease Control and Prevention introduced a substantial revision to its autism and vaccines information page on 19 November 2025. It specifically replaced earlier definitive wording that rejected any causal relationship. The new text states that the statement that vaccines do not cause autism is not an evidence-based claim under the Data Quality Act.
A thorough look at the page suggests that the changes were made without referencing credible materials. Media outlets like CNN have reported that many career CDC scientists were not informed of the revision. Internal sources also described heightened concern regarding potential direction within review pathways overseen by Robert F. Kennedy Jr.
The updated page cited the Data Quality Act and asserts that prior categorical statements about autism and vaccines lacked evidentiary grounding. The new text also referenced studies suggesting possible associations. Note that large epidemiologic cohorts across several countries since the 2000s have found no causal relationship between routine vaccination and autism.
Scientific groups and autism research organizations issued rapid statements warning that the revised language could inflate uncertainty about vaccine safety. Experts further argued that misrepresenting consensus evidence may undermine immunization programs already strained by declining uptake and recurrent measles outbreaks beginning in 2025.
The Autism Science Foundation said that the new autism webpage of the CDC distorts science and dismisses decades of evidence on vaccine safety. The Infectious Diseases Society of America noted that the change was driven not by science but by politics, and there is no scientific rationale for the CDC to change its long-standing assertions about vaccine safety.
Legislators responded with requests for clarification about the decision pathways that led to the update. Senator Bill Cassidy reiterated the expectation for clear guidance. Other lawmakers sought explanations regarding authorship, timing, and scientific justification for the November revision during ongoing congressional oversight hearings convened in Washington.
Multiple reports indicated that career CDC scientists were unaware of the final wording until after publication. This intensifies concern that the editing authority had shifted toward political appointees. Observers said the process diverged from standard CDC review structures that typically involve multilayer clearance before guidance language is approved or amended.
Critics emphasized that extensive cohort data from Denmark, the United Kingdom, and the United States have found no increase in autism incidence following MMR vaccination or exposure to vaccine formulations containing thimerosal. They warned that altered messaging may heighten hesitancy during a period marked by rising infection clusters nationwide.
Unresolved questions include the identification of officials who approved the new wording, the scope of the HHS assessment referenced in the update, and whether the CDC will restore prior language after internal review. Public health experts and thought leaders believe that the incident demonstrated risks from policy-driven revisions to scientific resources.
FURTHER READINGS AND REFERENCES
- Autism Science Foundation. 20 November 2025. “CDC’s New Autism Webpage Distorts Science and Rejects Decades of Evidence on Vaccine Safety.” Autism Science Foundation. Available online
- Goodman, B. 21 November 2025. “CDC Website Changed to Include False Claims that Link Autism and Vaccines.” CNN. Available online
- Infectious Diseases Society of America. 20 November 2025. “Statement on CDC’s Vaccines and Autism Webpage.” Infectious Diseases Society of America. Available online