U.S. Centers for Disease Control and Prevention (CDC) Director Susan Monarez was fired Wednesday after refusing to support vaccine policy changes advanced by Health Secretary Robert F. Kennedy Jr. that she believed contradicted scientific evidence, a close associate said.
Her dismissal comes less than a month into her tenure and has triggered the resignation of three top CDC officials, highlighting deepening divisions over U.S. public health policy.
The White House said Monarez was “not aligned with the president’s mission to “Make America Healthy Again” and confirmed that President Donald Trump dismissed her after she refused to resign. Jim O’Neill, currently deputy secretary of Health and Human Services, has been named interim CDC director.
Richard Besser, a former acting CDC director, said Monarez told him she was asked to take actions she considered both “illegal” and “in the face of science.” She also refused to dismiss senior colleagues without cause.
Following her ouster, Chief Medical Officer Debra Houry, National Center for Immunization and Respiratory Diseases Director Demetre Daskalakis, and National Center for Emerging and Zoonotic Infectious Diseases Director Daniel Jernigan resigned in protest. CDC staff cheered and applauded them as they departed the Atlanta campus.
The departing officials cited rising health misinformation, political attacks on science, and attempts to cut the agency’s budget. “I took the Hippocratic oath that said, ‘First, do no harm.’ I believe harm is going to happen, and so I can’t be a part of it,” Daskalakis told Reuters.
Kennedy, who has overseen sweeping changes since taking office this year, has dismantled the CDC’s expert vaccine advisory panel and replaced it with hand-picked advisers, including anti-vaccine activists. He has made false claims about vaccines, including that measles shots contain cells from aborted fetuses and that mumps vaccines do not work.
Monarez, during her Senate confirmation hearing, testified that she had seen no evidence linking vaccines to autism—a view consistent with scientific consensus but at odds with Kennedy, who has promoted the discredited claim.
According to Reuters, Kennedy defended the shake-up in a Fox News interview, saying, “The agency is in trouble, and we need to fix it. And it may be that some people should not be working there anymore.”
The turmoil at the CDC adds to a series of high-profile firings under Trump’s administration, which has moved aggressively to reshape independent agencies. Monarez is the third Senate-confirmed regulator dismissed in recent days.
The CDC, once seen as a cornerstone of U.S. and global public health, now faces mounting criticism for rolling back vaccine recommendations for pregnant women and children with health complications. With leadership in flux, the agency’s future direction remains uncertain.
