California defends standard childhood vaccine schedule amid federal proposal to split MMR doses
California health officials reaffirm the safety and necessity of the combined MMR vaccine and the existing school immunization requirements, rejecting a Trump administration order to separate the shots.
California’s public health department said the state will continue to require the combined measles, mumps and rubella (MMR) vaccine and the current schedule of childhood immunizations, despite a recent executive order from the White House proposing that the MMR be administered as three separate shots.
Dr. Erica Pan, director of the California Department of Public Health, said the combined vaccine is safe and essential for children’s health and for maintaining low measles rates in the state. She noted that California’s school-entry vaccine requirements have helped keep outbreaks limited compared with other regions.
President Trump signed an order calling for the MMR to be split into three separate injections and for all childhood vaccines to be given at separate visits “to the maximum extent feasible.” He suggested that separate doses might reduce lethality, a claim that the American Academy of Pediatrics and the Infectious Diseases Society of America described as unscientific and dangerous.
The Academy’s president, Dr. Andrew Racine, said dozens of studies involving millions of people have found no link between vaccines and autism, and warned that federal officials are promoting a disproven idea that could scare families. The Infectious Diseases Society of America reiterated that the MMR vaccine does not cause autism and prevents thousands of deaths worldwide each year.
California law, enacted after a 2015 measles outbreak, requires five immunizations for kindergarten entry, including the combined MMR shot, and allows exemptions only for medical reasons or for students in independent study programs. The state’s kindergarten vaccination rate has remained above 95% since the law’s implementation, reaching 96.1% for the 2024-25 school year.
Nationally, measles cases have risen, with more than 2,500 reported this year, the highest annual total since 1991. Health officials warned that separating the MMR vaccine would increase the number of clinic visits and injections without any scientific justification, as no manufacturers produce separate measles, mumps, and rubella vaccines.
"There is no data supporting doing this in separate shots," Pan said. "And, in fact, it will take more visits and more pokes in the arm for children to do this."