Trump signs executive order to split up MMR vaccine

• The executive order states that "the combined MMR vaccine should be administered in three separate single-disease shots once such products are domestically available and that, to the maximum extent feasible, all childhood immunizations should be administered at separate medical visits."

The big picture: Health Secretary Robert F. Kennedy Jr.'s handpicked vaccine advisers last fall called for splitting up the MMR shot and overhauling a central component of childhood immunizations.

• But the White House urged Kennedy to back off of such contentious policymaking earlier this year.
• And yet, President Trump has recently questioned Kennedy about the lack of momentum on childhood vaccine policy, per the Wall Street Journal, signaling his continued strong personal interest in the topic.

What he's saying: "You have the MMR. We want it in three separate vaccinations, given at separate times," Trump said at an Oval Office signing event.

• He suggested the MMR vaccine could be "quite lethal" when administered all at once, and likened the volume to "a bottle of soda."

Reality check: The CDC says there's "no published scientific evidence [that] shows any benefit in separating the combination MMR vaccine into three individual shots."

• It says there can be a "very small risk" of febrile seizures and extremely rare cases of serious allergic reactions, but that getting the MMR vaccine "is much safer than getting measles, mumps, or rubella."
• In addition, vaccine safety experts at CDC and the American Academy of Pediatrics agree the MMR shot is not responsible for recent increases in autism diagnoses.

"I'm a doctor. This executive order is wrong. The President does not have the expertise to make these changes," Sen. Bill Cassidy (R-La.), chairman of the Senate health committee, wrote on X.

• "Breaking up vaccines will mean children have to get more shots to get the same protection, not fewer shots. It will increase hesitancy and make children less safe."

Threat level: Public health experts said the move could make it more expensive and time-consuming for children to get vaccinated against measles, mumps and rubella at a time when measles cases for 2026 have already surpassed last year's total.

• It's also not clear whether health insurers will cover the extra pediatrician visits that the White House is calling for.
• There currently are not separate vaccines for measles, mumps and rubella. Companies would have to do clinical trials to bring each through the approval process.

Between the lines: There's no evidence that the childhood vaccine schedule in place prior to Trump's second term poses any risk to children's health, including by raising the risk for autism.

• Courts have frozen an administration attempt to pare the federal list of recommended childhood vaccines and otherwise limit who can obtain some shots.
• Vaccine supporters say splitting up the MMR shot by definition requires more doctor visits, raising the chance of missed visits and skipped immunizations.

This story has been updated with Trump's comments on the executive order, Cassidy's statement on X and additional reporting.