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President Donald Trump has ordered a reduction in childhood vaccines — publicly faulting the shots for an increase in autism cases — even as the nation’s top health official, Robert F. Kennedy Jr., has failed to produce evidence linking vaccinations to the disorder.
While the executive order released Aug. 10 does not directly mention autism, Trump’s demand to limit vaccine recommendations has puzzled leading medical groups, doctors, and political analysts alike. The directive landed less than 90 days before midterm elections, which Trump’s own pollsters have warned could be jeopardized by anti-vaccine rhetoric.
“The political timing, particularly for members on the Republican side in swing districts, is not good,” said Larry Bucshon, a former Republican congressman and retired doctor.
Trump’s willingness to gamble on the issue underscores the president’s impatience for his health secretary to deliver on a promise that he’d pinpoint a culprit for the sharp rise in autism diagnoses.
After more than a year, Kennedy and his close, anti-vaccine allies have blown past a deadline to turn up definitive answers in a multimillion-dollar research mission shrouded in secrecy, leaving the president to recycle debunked notions as he publicly assaults vaccines.
“This is about the most closed project that I’ve ever heard of,” Helen Tager-Flusberg, a renowned psychologist who runs the Coalition of Autism Scientists, said of Kennedy’s autism research efforts. “They’re treating it like the Manhattan Project in the 1940s. This is as opaque as it could possibly be.”
The White House did not answer questions about what research is informing the president’s opinions or which vaccines he believes could be linked to autism.
The Department of Health and Human Services said the president’s action builds on the agency’s January announcement that it was reassessing the nation’s vaccine schedule and recommended reducing childhood immunizations based on peer countries’ guidance. However, no other peer country separates the measles, mumps, and rubella vaccine as the president has now ordered.
“As the secretary said, HHS will examine every biologically plausible hypothesis, follow the evidence wherever it leads, and make findings and actions available as they are ready,” HHS spokesperson Emily Hilliard said in an email.
Trump especially has been enamored with finding autism’s cause, saying in August 2025 that it will be “such a big day” after Kennedy assured his boss that he had identified “clearly, almost certainly” factors causing autism that would soon be publicly revealed.
Decades of existing research and scientific studies show genetics is a leading factor. Environmental factors — including prenatal exposure to pollution, the age of the father, and maternal health — can also play a role.
But Kennedy has flatly rejected that science, often calling autism a “preventable disease.” As health secretary, he has spent millions of taxpayer dollars looking for root causes in a research effort that’s offered no public status updates and few details about who, or even which agency, is leading the effort.
Prominent autism advocacy groups, scientists, and researchers have not been consulted on the project. Nor have career scientists working at the federal health agencies, according to two officials KFF Health News is not naming because they were not authorized to speak on the record about the matter.
Requests to meet with Kennedy on the issue have been ignored, said Delancy Allred, public policy manager at the Autism Society. Allred said that other federal agencies, such as the Department of Education, have engaged more directly with leading autism advocacy groups during meetings.