President Donald Trump has signed an executive order seeking to overhaul decades of federal guidance on childhood vaccines and urging states to reconsider school vaccine mandates.
The order, called the "Gold Standard Childhood Vaccine Recommendations," divides childhood vaccines into three categories and directs federal agencies to advance the new recommendations. It also revives a long-standing priority of Trump's: breaking up the combined measles, mumps and rubella (MMR) vaccine into three separate shots, citing concerns about a now-debunked link to autism.
The order calls for all childhood immunizations to be administered at separate medical visits "to the maximum extent feasible." Medical experts have long said the single MMR shot is safe and effective, and that splitting it up could leave children vulnerable to disease for longer.
The order acknowledges that the administration's earlier vaccine directives have been "delayed due to litigation" and instructs federal agencies to advance the new recommendations "to the fullest extent allowable by law." The order is largely symbolic, since states hold the power over school vaccine mandates, not the federal government. Even changes to the federal vaccine schedule would require formal rulemaking through the Centers for Disease Control and Prevention (CDC) and its advisory committee.
The order comes as measles cases surge nationwide. The CDC has recorded 2,465 cases across 47 states so far in 2026, already surpassing last year's total, with 93 percent of cases in unvaccinated people. Childhood vaccination rates have dropped to 92.5 percent, leaving nearly 300,000 children vulnerable.
Current vaccine schedule
The MMR vaccine is 97 percent effective at preventing infection, adverse effects are rare, and there is no scientific evidence that separating the vaccines provides any medical benefit. The CDC's current MMR dosing schedule calls for two doses: the first between 12 and 15 months of age, and the second between four and six years old, before children start school.
Under the current CDC schedule, vaccines are generally spread across multiple doctor visits during a child's first year and a half, at two, four, six, 12 and 15 months. Children receive a few shots at each visit rather than all at once, a schedule medical experts say is carefully studied and proven safe.
The executive order does not provide a specific updated schedule with ages and timing. It directs agencies to review the recommendations and adjust the schedule "as appropriate."
The order builds on a change announced in January, when the Department of Health and Human Services cut the number of vaccines recommended for all children from 17 to 11. Under the administration's proposed overhaul, which is advisory and cannot be mandated, vaccines for 11 diseases including measles, mumps, polio and whooping cough would be recommended for all children. Vaccines for hepatitis A and B and meningococcal disease would be recommended only for high-risk groups or through shared decision-making between parents and doctors. Flu and COVID-19 shots would also fall into that shared decision-making category.
Trump's comments on the MMR vaccine
Trump said Monday that together, the combined vaccines could possibly be lethal, while separately they appear not to be lethal at all and instead very effective. He said that at one year old, children should have five separate visits for vaccines rather than getting them all on the same day.
He said he had seen proof early on of what looked like a vaccination the size of a bottle of soda poured into a small child's body, and that bad things happen in many cases.
There is no evidence that the combined MMR vaccine is lethal. Serious side effects are extremely rare, and the risks of the vaccine are vastly outweighed by the risks of the diseases it prevents. Before the measles vaccine existed, about 500 children died from measles every year in the United States. According to the CDC, about 1 to 3 out of every 1,000 children infected with measles will die from complications, while there have been no deaths shown to be related to the MMR vaccine in healthy people. Doses of live viruses like those in the MMR vaccine are a tiny fraction of a teaspoon.
Medical groups push back
Many states now follow guidance from the American Academy of Pediatrics (AAP) and other major medical groups, which recommend vaccines based on a child's immune system development and oppose nonmedical exemptions. Those groups split from the CDC schedule over what they called a departure from "long-standing medical evidence."
Dr Sean O'Leary, chair of the AAP Committee on Infectious Diseases, said the AAP recommends immunizations designed to teach the immune system to recognize and resist serious diseases. He said they are carefully tested and monitored over time, and that the pacing and combination of vaccines are based on what is known about when a child's immune system is ready to learn and respond best.
Trump's push to split the MMR vaccine stems from a long-held personal belief rooted in a debunked theory linking childhood vaccines to autism. He has publicly questioned whether the number of vaccines children receive can cause autism, despite decades of research finding no link. He has framed the issue as a matter of "common sense," telling reporters last year that it was based on what he feels, that mixing vaccines seemed to cause problems, and that there was no downside to taking them separately since it was thought to be better. He has said that he and First Lady Melania Trump deliberately spaced out vaccines for their son Barron, describing it as "the old-fashioned way."
Legal challenges and CDC changes
A federal judge blocked similar changes in March, siding with major medical organizations that argued Health Secretary Robert F Kennedy Jr had unlawfully changed vaccine policy and improperly reconstituted the federal panel that advises the government on vaccines. More than 40 studies involving over 5.6 million people have found no link between the MMR vaccine, or any vaccine, and autism. The 1998 study that originally sparked fears was retracted, its author lost his medical license, and subsequent research has repeatedly reaffirmed the safety of childhood vaccines.
In late 2025, Kennedy directed the CDC to remove explicit statements from its website declaring that vaccines do not cause autism. The agency updated its text to instead highlight areas needing further observation, prompting criticism from public health groups. The latest CDC data shows that 1 out of 31 children were diagnosed with autism by the time they turned 8, up from 1 out of 36 just two years earlier, an increase linked to broader diagnostic criteria, better screening and greater awareness rather than vaccines.
Insurance coverage unchanged for now
Private insurers are still required to cover all vaccines recommended by the CDC's Advisory Committee on Immunization Practices at no cost, including those in the "shared clinical decision-making" category, and the order does not change that. Major health insurers have also pledged to continue covering the broader September 2025 vaccine schedule through at least 2026, and some states have passed laws requiring insurers to cover vaccines beyond the federal minimum. The one exception is HPV: insurers are no longer required to cover additional doses beyond the newly recommended single dose, though some plans have pledged to do so temporarily.
