WASHINGTON (AP) — President Donald Trump on Monday signed an executive order calling for revamped childhood vaccine recommendations that promote his long-held but discredited theory that childhood shots should be spaced out into separate medical visits.

The order advocates separating the measles, mumps and rubella (MMR) vaccine into three different shots administered in separate appointments, and directs the nation’s health department to improve vaccine research, according to a White House fact sheet on the order. Separate measles, mumps and rubella vaccines for children are not currently available in the United States, and vaccines are already extensively researched.

Speaking about the order at the Oval Office on Monday, Trump repeatedly suggested the number or timing of vaccines could play a role in rising rates of autism spectrum disorder, even as scientific consensus and decades of studies have firmly concluded there is no link. He also touted several changes to the childhood vaccine schedule that his health department has already attempted, but that have been blocked by a federal judge.

The renewed focus on vaccines marks a departure from his administration’s recent efforts to emphasize less controversial health policies related to healthy eating, drug price negotiations and medical fraud crackdowns ahead of November’s midterm elections.

Public health experts have raised concerns that spacing out shots as Trump suggests can lead to an increased risk that children become infected with a vaccine-preventable disease before returning for another visit. Childhood vaccines — and how and when to give them in combination — go through rigorous studies, and safety tracking continues for years as the shots are used.

Michael Osterholm, a University of Minnesota expert on infectious diseases, said parents should continue to rely on vaccine recommendations developed by medical and public health experts such as the American Academy of Pediatrics.

“Today’s Executive Order does not change the underlying scientific evidence supporting childhood immunization. That data has been built over decades — through large clinical trials, real-world effectiveness studies and continuous safety monitoring involving millions of children,” he said in a statement.

Who’s in charge of vaccine policy?
Even as the order calls for revised vaccine recommendations, states, not the federal government, have the authority to require vaccinations for schoolchildren. The order advises states with school vaccine mandates to consider updating their laws to reflect the administration’s preferred schedule, the fact sheet said.

Last December, Trump ordered the Department of Health and Human Services to review how peer nations approach vaccine recommendations and consider revising U.S. guidance accordingly. The department responded by cutting the number of vaccines it recommends for every child, a move that has since been blocked in court.

Changes to federal childhood vaccine recommendations customarily require approval from the director of the Centers for Disease Control and Prevention. The newly Senate-confirmed CDC director, Dr. Erica Schwartz, oversaw policies promoting vaccination of service members while in a leadership position at the U.S. Coast Guard.

However, public health law expert Lawrence Gostin at Georgetown University said the Supreme Court’s interpretation of Trump’s power may allow him to supersede Schwartz if she does not agree to new recommendations.

“This is clearly the first test for Dr. Erica Schwartz,” Gostin said in an email. “The President is placing her in an untenable position.”

Health Secretary Robert F. Kennedy Jr., a longtime anti-vaccine activist before he entered politics, set out to overhaul immunization guidance at DHS in the first year of Trump’s term. He fired an entire 17-member vaccine advisory committee, installing replacements who made far more restrictive recommendations that have since been halted by a federal judge. He also personally directed the CDC to abandon its position that vaccines do not cause autism, without supplying any new evidence to support the change.

In the months leading up to Monday’s announcement, Trump’s administration had largely pivoted away from talking about vaccine policy in favor of less polarizing topics like healthy eating and efforts to lower drug prices ahead of November’s elections. Polls show most Americans still support school vaccine requirements, though Republicans are less likely than Democrats to see them as important.

Still, Trump has been fixated on connecting autism to vaccines. He has recently ramped up pressure on Kennedy to identify the cause of autism, something Kennedy had pledged to do with new research unveiled last year. Trump publicly prodded the health secretary for an update on autism research in a Cabinet meeting last month.

“How are you doing on the autism research?” Trump asked.

“We will have an answer for you,” Kennedy said.

Scientific consensus and decades of studies have firmly concluded there is no link between childhood vaccines and autism. On Monday, Kennedy repeated his assertion that he believes an unknown environmental factor is to blame for rising autism diagnoses and said that his department will deliver research findings “as soon as they are ready.”

Monday’s order comes as students are returning to classrooms around the country and the nation contends with a measles outbreak that experts say could result in the U.S. losing its measles elimination status.

Doctors have raised concerns that Trump’s falsehoods on vaccines could stoke vaccine hesitancy. Federal data shows U.S. kindergarten vaccination rates have been dropping, with the share of children with exemptions rising to an all-time high in the 2024-25 school year.

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