On Wednesday, the Centers for Disease Control and Prevention quietly rewrote its public guidance on autism and vaccines. For years, the CDC’s vaccine safety page clearly stated that extensive scientific evidence shows vaccines do not cause autism. Overnight, that message shifted from evidence-based clarity to manufactured ambiguity — without consultation or approval from CDC’s vaccine and autism scientists.
The prior version reflected decades of research conducted and validated by CDC experts across immunology, epidemiology and pediatrics, and endorsed by clinicians worldwide. The new version, changed at the direction of Health and Human Services Secretary Robert F. Kennedy Jr., reframes settled evidence as uncertain, emphasizes alleged “gaps” in past studies and introduces speculative biological mechanisms long promoted by anti-vaccine activists but not accepted by the scientific community.
When you remove scientists from science, you don’t get truth. You get ideology.
Career staff across multiple CDC centers have told us that no scientific offices — or their leadership — were asked to review or clear the new content. (The Washington Post reported the same, citing five agency officials.) In an interview with The New York Times on Thursday, Kennedy said he personally ordered the changes.
This is not science. It is propaganda.
When you remove scientists from science, you don’t get truth. You get ideology. The secretary’s apparent aim is not to clarify evidence but to manufacture doubt and hand opportunists a government-branded document they can use to prey on anxious parents. Why invest in rigorous research when you can exploit the credibility of the nation’s leading public health agency to turn conspiracy theory into policy?
The shift is more significant than a mere change in tone, reframing long-settled evidence as “incomplete” and citing studies not recognized by scientific experts. This will leave families uncertain about whether vaccines are safe. As physicians, we remember the era before routine vaccination — children dying when their throats swelled shut from epiglottitis, suffering brain injury from meningitis or becoming infertile from mumps.
Despite the real consequences for children’s health, the secretary has also used this rewrite to troll Congress. During Kennedy’s confirmation hearings, Senate HELP Committee Chair Bill Cassidy asked Kennedy for assurance that he would not alter CDC vaccine guidance or promote unsupported claims. Kennedy agreed. The header “Vaccines do not cause autism” remains on the page — but HHS added a footnote stating that it “has not been removed due to an agreement” with the senator.
Cassidy asked for a promise; the secretary gave him an asterisk.
If the nation’s top health official will not honor his word on something this central to public health, how can Americans trust him to lead an agency responsible for protecting 330 million people? Given that Kennedy has said, “I don’t think people should be taking medical advice from me,” why is he rewriting clinical information for families?
For the public, the stakes are immediate. More distrust means more outbreaks of preventable disease and more avoidable deaths.
Clinicians depend on CDC guidance to counsel patients and make evidence-based decisions. By injecting doubt, HHS has made official guidance less trustworthy — not more — and implicitly asked health professionals to ignore their own government. Health systems and state officials are also increasingly distancing themselves from HHS and CDC.
For the public, the stakes are immediate. More distrust means more outbreaks of preventable disease and more avoidable deaths. Public health agencies exist so parents do not have to conduct their own literature reviews on virology and neurodevelopment to keep their children safe. Replacing scientific expertise with ideological messaging leaves families to fend for themselves in a landscape already saturated with misinformation. Kennedy often describes his approach as “gold standard science” and “radical transparency.” But transparency is not the same as amplifying fringe studies, and science is not an open-ended invitation to relitigate well-studied questions because political leadership dislikes the answers. This shift represents a fundamental reversal from evidence-based decision-making to decision-based evidence-making. Public health cannot function this way. Agencies cannot protect Americans if political appointees override scientific findings, rewrite research to suit ideology or exclude experts from decisions about their own work. Every living former U.S. Surgeon General, across both parties, has already called for the secretary’s removal. So have dozens of major medical associations. Congress— especially the Senate that confirmed him — must now decide whether to intervene. The rewriting of the CDC’s guidance is not a routine update — it is a warning. If scientific consensus can be erased with a keystroke and replaced with politically curated doubt, the institutions meant to safeguard national health are at risk. Under Secretary Kennedy, CDC materials can no longer be assumed to reflect scientific authority. This is not how the nation’s highest-ranking health official should operate, and the public should not mistake his directives for medical advice.
Daniel Jernigan is the former director of CDC’s National Center for Emerging and Zoonotic Infectious Diseases.
Demetre Daskalakis is the former director of the CDC’s National Center for Immunization and Respiratory Diseases.
Debra Houry is the former chief medical officer and deputy director for program and science at the CDC. 
