Trump Signs Executive Order Splitting MMR Vaccine Into Individual Doses Despite Medical Opposition

President Trump signed an executive order on August 11, 2026, directing federal health agencies to make individual measles, mumps, and rubella vaccines available separately, as an alternative to the standard combined MMR shot.

The order instructs the Department of Health and Human Services to work with manufacturers to ensure single-antigen vaccines are available within 18 months. It also directs the FDA to expedite any necessary reviews.

The American Academy of Pediatrics, the American Medical Association, and the CDC all said the order is not supported by scientific evidence. These organizations said the combined MMR vaccine is safe, effective, and has been used for decades without significant safety concerns. They warned that splitting the vaccine into three separate shots could reduce overall vaccination rates by requiring more doctor visits.

The administration framed the order as a matter of parental choice. Health Secretary Robert F. Kennedy Jr., who has long questioned vaccine safety, said parents should have the option to choose individual vaccines if they prefer.

Pediatricians said the practical challenges of administering three separate shots, including additional office visits and potential gaps in coverage, could leave children vulnerable to preventable diseases. Measles outbreaks have already been reported in several states this year.

Vaccine manufacturers said they would review the order and assess whether producing individual vaccines is feasible at scale. Some noted that demand for single-antigen vaccines has historically been low, which has limited production.

Public health officials said they are concerned the order will fuel vaccine hesitancy and complicate efforts to maintain herd immunity against measles, which requires vaccination rates above 95 percent.