CDC Official Calls for Splitting MMR Vaccine, Raising Public Health Concerns
The Centers for Disease Control and Prevention’s acting director proposed today that the measles, mumps, and rubella (MMR) vaccine be administered as three separate shots, a move that has sparked debate among public health experts.
The proposal, echoing similar statements made by former President Donald Trump in September, has raised alarms due to concerns it could reduce vaccination rates and increase healthcare access barriers. Dr. Leana Wen, an emergency physician and clinical associate professor at the George Washington University, explained the historical impact of these diseases, noting that before the measles vaccine, the U.S. saw an estimated 48,000 hospitalizations and 400 to 500 deaths annually. Rubella poses a significant threat to pregnant women, with a past epidemic in 1964-65 resulting in 11,000 lost pregnancies and 20,000 babies born with congenital rubella syndrome.
Currently, the MMR vaccine is a combined shot administered in two doses, streamlining the immunization schedule and reducing the number of doctor visits. While proponents of separate shots suggest potential flexibility and a perceived reduction in side effects, Dr. Wen emphasized that there’s “no evidence that the separate vaccines are safer or more effective than the combined MMR shot.” She also pointed out that the development and FDA approval of new vaccines would take years. The CDC’s recommended immunization schedule and further information on vaccine safety can be found on the CDC website. This change comes as measles cases are already on the rise, with 1,544 confirmed cases in 2025 – the highest number in 25 years.
Declining vaccination rates put vulnerable populations at increased risk, including newborns too young to be vaccinated, individuals with weakened immune systems, and older adults. Protecting these groups relies on maintaining high levels of herd immunity. The acting CDC director has requested manufacturers begin developing individual vaccines, but public health officials remain concerned about the potential consequences of disrupting a well-established and effective vaccination program.
