The Centers for Disease Control and Prevention (CDC), the nation’s premier public health agency, has been plunged into unprecedented turmoil following the abrupt firing of its director, Susan Monarez, and the near-simultaneous resignation of several top officials. The shake-up, which unfolded over the last days of August 2025, has sparked bipartisan alarm, ignited fierce debate about vaccine policy, and left the CDC’s future direction uncertain.
It all began on August 27, when the White House announced that Monarez—who had only been sworn in as CDC director on July 31—was being removed from her post. The move was reportedly at the urging of Health and Human Services (HHS) Secretary Robert F. Kennedy Jr., who has drawn widespread controversy for his anti-vaccine positions and efforts to reshape federal health policy. According to The Associated Press, the White House said Monarez was “not aligned with” President Donald Trump’s agenda, while Kennedy himself warned, “There’s a lot of trouble at the CDC and it’s going to require getting rid of some people over the long term, in order for us to change the institutional culture.”
Monarez’s ouster came less than a month after her Senate confirmation and swearing-in, making her the shortest-serving director in the CDC’s history. Her lawyers quickly challenged the legality of her firing, arguing that only the president could formally remove her and that the action was “legally deficient.” In a statement, attorneys Mark Zaid and Abbe Lowell said Monarez was targeted after she refused “to rubber-stamp unscientific, reckless directives and fire dedicated health experts.” They added, “It is about the systematic dismantling of public health institutions, the silencing of experts, and the dangerous politicization of science.”
Within hours of the announcement, a wave of resignations swept through the CDC’s senior ranks. Dr. Debra Houry, the agency’s chief medical officer; Dr. Demetre Daskalakis, director of the National Center for Immunization and Respiratory Diseases; Dr. Daniel Jernigan, director of the National Center for Emerging and Zoonotic Infectious Diseases; and Dr. Jen Layden, director of the Office of Public Health Data, Surveillance and Technology, all stepped down in protest. According to NBC, the exodus was “near-immediate,” with hundreds of CDC staff gathering to applaud the departing officials as they left the Atlanta campus.
The resignations were accompanied by public statements of concern. Daskalakis, in a resignation letter posted to X (formerly Twitter), wrote, “The administration’s new policies do not reflect scientific reality and are designed to hurt rather than to improve the public’s health,” adding that recent changes in the immunization schedule “threaten the lives of the youngest Americans and pregnant people.” Houry told The Associated Press that Monarez had tried to guard against political meddling in scientific research and health recommendations. “We were going to see if she was able to weather the storm. And when she was not, we were done,” she said.
At the heart of the dispute are sweeping changes to the CDC’s vaccine policies and its influential Advisory Committee on Immunization Practices (ACIP). Kennedy, who has long been a leader in the anti-vaccine movement, recently dismissed the entire ACIP panel, accusing its members of being too closely aligned with vaccine manufacturers, and replaced them with a group that includes several vaccine skeptics. The new panel is scheduled to meet on September 18 to review recommendations for standard childhood vaccines—including those for measles, hepatitis B, mumps, rubella, chickenpox, and COVID-19. According to a government notice, these vaccines have been “settled fixtures for children,” but the legitimacy of the upcoming meeting is being called into question.
Senator Bill Cassidy, a physician and the top Republican on the Senate’s health committee, has called for oversight and urged that the ACIP meeting be postponed. “Serious allegations have been made about the meeting agenda, membership, and lack of scientific process being followed,” Cassidy said in a statement reported by The Associated Press. “These decisions directly impact children’s health and the meeting should not occur until significant oversight has been conducted.”
The White House, meanwhile, has doubled down on its support for Kennedy’s actions. Press Secretary Karoline Leavitt told reporters that President Trump had fired Monarez after she refused Kennedy’s demand that she resign. “Her lawyers’ statement made it abundantly clear themselves that she was not aligned with the President’s vision to make America healthy again,” Leavitt said. “The President has the authority to fire those who are not aligned with his mission.”
The fallout from the leadership shake-up comes at a time when the CDC is already reeling from external threats and internal dissent. On August 8, a gunman opposed to COVID-19 vaccines opened fire at the CDC’s Atlanta headquarters, killing a police officer and targeting public health workers. A memorial to the officer remains outside the building, close to where staff gathered to say goodbye to the departing officials. The tragedy underscored the intensity of the backlash against vaccines and the risks faced by public health professionals.
Kennedy’s approach to vaccine policy has been especially contentious. He recently announced via social media that COVID-19 vaccine access would be restricted to higher-risk groups, but controversially excluded high-risk children and pregnant women from eligibility. This move, reported by the New York Times, drew sharp criticism from within the CDC and from medical organizations nationwide. Dr. Georges Benjamin, executive director of the American Public Health Association, told The Associated Press, “The scientific community is beginning to draw a line in the sand and say, ‘No way.’”
Supporters of the administration argue that the changes are necessary to restore trust in the CDC, which has faced criticism for its handling of the COVID-19 pandemic and for being out of step with public sentiment. Leavitt said that Trump and Kennedy “are committed to restoring trust and credibility to the CDC by ensuring their leadership and their decisions are more public facing, more accountable, protecting our public health systems and restoring it to its core mission of protecting Americans from communicable diseases, investing in innovation, prevent and respond to future threats.”
But critics warn that the rapid turnover, erosion of scientific safeguards, and politicization of vaccine policy threaten to undermine the agency’s credibility and the health of millions. Dr. Richard Besser, a former CDC acting director, told The Associated Press that Monarez “was one of the last lines of defense against this administration’s dangerous agenda.” Senator Bernie Sanders called the firing “dangerous” and demanded an investigation, urging Senate hearings into the matter.
As the dust settles, the CDC faces a leadership vacuum and a crisis of confidence. Jim O’Neill, a former investment executive with no medical background, has been tapped to replace Monarez as acting director, though it’s unclear if he will retain both his HHS and CDC roles. The agency’s next moves—especially the fate of its vaccine advisory panel—will be closely watched by lawmakers, scientists, and the public alike.
For now, the CDC’s mission to protect Americans from infectious diseases is being tested like never before, as the nation debates the balance between science, politics, and public health in the wake of a historic upheaval.
