Dr. Mehmet Oz, who leads the Centers for Medicare and Medicaid Services, stated unequivocally that the Measles, Mumps, and Rubella (MMR) vaccine is not lethal, directly contradicting claims made by former President Donald Trump. Oz's clarification came during an appearance on CBS' "Face the Nation" on Sunday, following repeated questioning from host Margaret Brennan.
Trump had previously suggested, without providing evidence, that the combined MMR vaccine could be "quite lethal," while separate components might be less so. This assertion was made less than two weeks prior, when Trump signed an executive order aimed at revising federal childhood vaccine recommendations and called for the separation of the MMR vaccine's components. However, separate measles, mumps, and rubella vaccines are not currently available in the United States, and the combined MMR vaccine has been administered for over four decades, with more than 800 million doses given globally since 2021, according to research cited by Politico.
During the interview, Brennan pressed Oz on Trump's remarks, asking him to clarify whether the president was incorrect. Oz initially attempted to steer the conversation toward patient choice and consultations with healthcare providers. It was only after Brennan persisted, noting that individual MMR vaccines are not offered in the U.S. and that Merck does not provide them separately, that Oz definitively stated, "The MMR vaccine is not a lethal vaccine."
Oz suggested that a key concern for the administration is ensuring parents feel empowered to question vaccination requirements. "The challenge we're running into is that many states have not clarified that, and actually, it's harder for parents to ask these difficult questions," he said. He also noted that separate MMR vaccines are available in other countries.
The exchange occurs amid a rise in measles cases, which have reached their highest level in 35 years. The Trump administration itself has encouraged childhood vaccinations against measles. Despite these efforts, vaccination rates among young children have declined, with measles vaccination coverage for U.S. kindergarteners falling from 95.2% in the 2019-2020 school year to 92.4% in 2025-2026. This rate is below the approximately 95% needed for herd immunity against the highly contagious virus.
Measles is characterized by fever, cough, runny nose, and a rash, but can lead to severe complications such as pneumonia and encephalitis. The MMR vaccine has been a long-standing component of childhood immunization programs. Trump's executive order earlier this month called for a reevaluation of federal childhood vaccination guidelines, including his proposal to separate the MMR vaccine components. However, implementing this proposal faces the immediate hurdle that individual measles, mumps, and rubella vaccines are not currently marketed in the United States.