The White House has mounted a vigorous defense of Health and Human Services Secretary Robert F. Kennedy Jr. as a leadership crisis engulfs the Centers for Disease Control and Prevention (CDC), following the abrupt firing of CDC Director Susan Monarez and a wave of high-profile resignations. The turmoil, which has unfolded over the last week of August 2025, has sparked bipartisan concern in Congress, alarm among public health experts, and fresh scrutiny of the Trump administration’s approach to vaccine policy and scientific governance.
On August 27, 2025, Susan Monarez was fired just weeks into her tenure as CDC director, after a tense confrontation with Secretary Kennedy over vaccine policy. According to Bloomberg, this clash was the culmination of mounting disagreements, with Monarez pushing back against Kennedy’s controversial vaccine stance during a meeting at Health and Human Services (HHS) headquarters in Washington, D.C. An internal staff message viewed by Bloomberg confirmed that Monarez had been asked to attend the meeting in person, a rare move for a director so early in her term.
White House spokesperson Kush Desai stated that Monarez was removed for not aligning with the President’s “Making America Healthy Again” agenda. Attorneys representing Monarez, however, argued she was “targeted” for refusing to “rubber-stamp unscientific, reckless directives and fire dedicated health experts.” Her lawyers warned, “The attack on Dr. Monarez is a warning to every American: our evidence-based systems are being undermined from within. Science and integrity can never be compromised.”
The fallout was swift and severe. At least three senior CDC leaders—Demetre Daskalakis, director of the National Center for Immunization and Respiratory Diseases; Debra Houry, chief medical officer and deputy director for Program and Science; and Dan Jernigan, director of the National Center for Emerging and Zoonotic Infectious Diseases—announced their resignations on August 27, citing irreconcilable differences with Kennedy’s leadership and policies. In his resignation email, Daskalakis wrote, “I am not able to serve in this role any longer because of the ongoing weaponizing of public health. You are the best team I have ever worked with, and you continue to shine despite this dark cloud over the agency and our profession.”
The exodus of top talent comes on the heels of massive layoffs earlier in August, when the CDC permanently fired 600 employees, including those working on infectious diseases such as bird flu and environmental hazards. The union representing the workers confirmed that the layoffs affected staff handling public record requests and critical research. The move intensified concerns about the CDC’s capacity to respond to new outbreaks and maintain scientific integrity.
Robert F. Kennedy Jr., a well-known vaccine critic who does not hold a medical degree, has made sweeping funding cuts and significant changes to U.S. immunization recommendations since taking office. These actions have angered public health experts and led to open disputes within the administration. The Food and Drug Administration, responding to Kennedy’s demands, narrowed Covid vaccine eligibility in 2025 to only those aged 65 and over or with underlying conditions, a sharp reversal from previous years when vaccines were recommended for most children and adults. Medical organizations, including the Infectious Diseases Society of America, have condemned the move, warning it puts millions of lives at risk.
Former CDC Chief Medical Officer Dr. Debra Houry, one of the officials who resigned, told the BBC that Kennedy’s policies “lacked scientific integrity.” She warned, “I am extremely worried that with continued resignations, terminations, retirements, all because of what’s going on through some of these policies, that we are not going to have the capacity to continue to do good science, to respond to an outbreak and to prevent chronic diseases.” Houry added that the worst-case result of Kennedy’s approach would be the disruption of the vaccine schedule for children, potentially leading to the resurgence of “preventable diseases throughout the US again, like polio and measles.”
Political reaction has crossed party lines. Several Democratic senators, including Georgia’s Jon Ossoff—who called Kennedy a “quack”—and Senate Minority Leader Chuck Schumer, have called for Kennedy’s resignation. Schumer stated, “Donald Trump knew Robert F. Kennedy Jr. would be a disastrous pick to lead health care in America and he nominated him anyway. Donald Trump made this mistake and now he must fire RFK Jr. immediately.” Senator Bernie Sanders, the ranking member of the Senate health committee, quickly called for a hearing with Kennedy about Monarez’s firing.
Republicans, too, have expressed unease. Maine Senator Susan Collins said there was “no basis” to remove Monarez and requested a congressional hearing to examine the agency’s leadership crisis. Senator Bill Cassidy, who chairs the Senate Health, Education, Labor and Pensions Committee, announced the panel would conduct oversight over the resignations and urged a delay for an upcoming vaccine advisory committee hearing, citing allegations that the panel lacked a “scientific process.” Cassidy warned, “If the meeting proceeds, any recommendations made should be rejected as lacking legitimacy given the seriousness of the allegations and the current turmoil in CDC leadership.”
In the midst of the upheaval, the White House moved quickly to name Jim O’Neill as acting CDC director. O’Neill, a senior HHS official and former tech investor with deep ties to Trump donor Peter Thiel, has been a close Kennedy ally and was confirmed as deputy HHS secretary in June 2025. O’Neill does not come from a medical background and is known for advocating a laissez-faire approach to federal regulation. In a 2014 speech, he argued the FDA should approve drugs based only on safety, not efficacy, and has been active in the “longevity” community, even serving on the board of the anti-aging SENS Research Foundation.
O’Neill’s appointment has drawn criticism from watchdog groups. Accountable US Executive Director Tony Carrk stated, “If made acting Director of the Trump CDC, Jim O’Neill would be in a prime position to ensure favorable outcomes for several medical industry startups he’s been financially linked to that have direct business before HHS and the CDC. How can American patients be sure that proper vetting of these companies would take place on O’Neill’s watch and that public health will be a higher priority over the profits of his former clients? They can’t.”
In his first public statement as acting director, O’Neill called the CDC the “beating heart of public health in America,” and pledged to rebuild trust and refocus the agency on infectious disease safety. He highlighted new investments in screening technology, the end of the Texas measles outbreak, and the cessation of what he described as the “misuse of the childhood immunization schedule for Covid vaccine mandates.” O’Neill said, “We are helping the agency earn back the trust it had squandered. I look forward to working with CDC’s dedicated team and announcing additions to the senior leadership in the weeks ahead.”
Meanwhile, Kennedy wrote an open letter to CDC employees after Monarez’s departure, stating, “I am committed to working with you to restore trust, transparency, and credibility to the CDC. Your daily efforts—often unseen—save lives. Reform does not diminish your work; it strengthens it. The American people are ready to believe in this agency again if we show them that integrity, accountability, and science guide every decision.” He added that he aims to rebuild the CDC into “a guardian of America’s health and security.”
As the dust settles, the CDC faces an uncertain future, with its leadership in flux, morale battered, and its scientific mission under intense debate. The coming months will test whether America’s premier public health agency can regain its footing—and the trust of a wary nation.
