Experts push back on plan to split MMR vaccine into separate shots

President Trump signed an executive order to reshape vaccine policy, including a directive to offer MMR as three separate shots given in separate visits. Public health experts and the CDC say there’s no evidence this would improve safety or uptake, and it would complicate logistics, raise costs, and likely reduce vaccination rates, increasing risk of measles, mumps, and rubella outbreaks. Monovalent vaccines exist in some places but are not common in the U.S.; developing and approving separate shots could take years, possibly a decade. Merck and GSK emphasize the safety and practicality of the current MMR vaccine, while Japan’s experience with monovalents is cited as cautionary. The plan also touches on long-debunked autism concerns, which researchers say have no basis.