Acting CDC Director Urges Separate Measles, Mumps, Rubella Vaccines Despite No Evidence

The acting CDC Director Jim O'Neill has publicly supported President Trump's call to split the combined measles, mumps, and rubella (MMR) vaccine into three separate monovalent shots, despite no scientific evidence supporting any benefit from this change. The combined MMR vaccine has been in use since 1971, designed to reduce the number of injections children receive, with the current two-dose regimen recommended between 12 months and 6 years of age. Experts and health organizations warn that separating the vaccine would increase the number of injections from two to six, potentially causing delays in immunization and increasing costs without improving safety. The CDC and vaccine makers emphasize there is no approved monovalent MMR vaccine in the U.S., and no data suggesting that splitting the vaccine would be safer or more effective. This move aligns with increasing vaccine skepticism and contradicts established public health guidelines, which recommend combined vaccinations to ensure timely and effective protection. The CDC recently accepted a separate recommendation to administer the chickenpox vaccine apart from the MMR shot, but this does not extend to splitting the MMR vaccine itself.