❓WHAT HAPPENED: Acting U.S. Centers for Disease Control and Prevention (CDC) Director Jim O’Neill called for the MMR vaccine to be split into three separate shots, echoing comments made by President Donald J. Trump.
👤WHO WAS INVOLVED: Jim O’Neill, Donald Trump, Health and Human Services Secretary Robert F. Kennedy Jr., and vaccine manufacturers Merck and GSK.
📍WHEN & WHERE: Statements were made on social media and in interviews in October 2025.
💬KEY QUOTE: “Break up the MMR shot into three totally separate shots (not mixed!)” – President Trump
🎯IMPACT: Spreading out measles, mumps, and rubella vaccinations could reduce side effects and give children’s bodies more time to adjust to them, but the health establishment is complaining that it could disrupt adherence to immunization schedules and increase the risk of contracting one of the illnesses between shots.
Jim O’Neill, Acting Director of the Centers for Disease Control and Prevention (CDC), is advocating for separating the MMR vaccine, which inoculates against measles, mumps, and rubella, into three separate doses. His stance echoes a social media post by President Donald J. Trump last month, when he wrote, “BREAK UP THE MMR SHOT INTO THREE TOTALLY SEPARATE SHOTS (NOT MIXED!), TAKE CHICKEN P SHOT SEPARATELY, TAKE [HEPATITIS] B SHOT AT 12 YEARS OLD, OR OLDER, AND, IMPORTANTLY, TAKE VACCINE IN 5 SEPARATE MEDICAL VISITS!”
O’Neill has supported this view, stating, “Thank you POTUS for your leadership. I call on vaccine manufacturers to develop safe monovalent vaccines to replace the combined MMR.”
Introduced in 1971, the MMR vaccine, manufactured by Merck and GSK, combined three vaccines previously licensed in the 1960s, and has long been controversial, with skeptics linking it to autism. Andrew Nixon, Communications Director for the Department of Health and Human Services (HHS), noted, “Standalone vaccinations can potentially reduce the risk of side effects and can maximize parental choice in childhood immunizations.”
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