Dr. Marty Makary's resignation as head of the Food and Drug Administration has further expanded a leadership vacuum already plaguing the U.S. Department of Health and Human Services. The departure, announced on Tuesday, leaves another major health agency with only an acting commissioner, compounding concerns over the department's stability and scientific credibility.
Multiple Vacancies Across HHS
At the start of the week, several senior positions at HHS were already empty. There was no Senate-confirmed surgeon general. The director of the National Institutes of Health was simultaneously serving as acting head of the Centers for Disease Control and Prevention. The FDA lacked a permanent vaccine chief after that official was removed for the second time in a year. Makary's resignation now adds the FDA commissioner role to the list of unfilled posts.
While some vacancies are typical in any administration—given the need for Senate confirmation in a narrowly divided chamber—critics argue the current level of upheaval is extraordinary. The lack of scientific expertise among leadership is particularly alarming, they say.
"It's a sign that something is not right in this department," said Dr. Daniel Jernigan, a former senior CDC official. The problem has been exacerbated by widespread cuts, firings, and the disruption caused by Health Secretary Robert F. Kennedy Jr.'s policies, according to detractors.
HHS did not immediately respond to a request for comment on Wednesday.
Public Trust at Stake
Kathleen Hall Jamieson, director of the Annenberg Public Policy Center at the University of Pennsylvania, noted that most Americans do not pay attention to agency leadership until a public health crisis emerges—such as the recent hantavirus outbreak. Such moments offer opportunities to rebuild trust in federal health agencies, which has declined in recent years.
"The key question for me is, when we need these agencies to speak, will they have the capacity to draw the science together and tell us what we need to know?" Jamieson said.
FDA Faces Ongoing Challenges
Makary leaves behind unfinished initiatives and reviews under scrutiny, including work on ultra-processed foods, food dyes, antidepressants, and COVID-19 vaccines. His permanent successor will face the same challenge that defined his tenure: balancing traditional Republican anti-regulatory interests with Kennedy's anti-corporate priorities, which focus on scrutinizing food, medicine, and vaccine ingredients.
The FDA is developing a first-of-its-kind definition of "ultra-processed foods," which Kennedy blames for rising rates of diabetes, obesity, and other chronic conditions. The task has fallen to Deputy Commissioner for Foods Kyle Diamantas, who recently called the effort "really hard." Diamantas, an attorney and friend of Donald Trump Jr., was tapped by Trump to lead the FDA on an acting basis and also serves as Kennedy's chief counselor. He is the first person in over half a century to head the FDA without a medical or scientific degree.
"Kyle Diamantas now has a nearly impossible charge," said Dr. Peter Lurie, a former FDA official now at the Center for Science in the Public Interest. "Leading, as a non-scientist, a science-based agency under an unqualified secretary who puts his own medical and nutritional pet peeves over evidence-based public health."
CDC Revolving Door
The CDC has experienced a rapid turnover of short-term directors. The Trump administration's first pick, former Florida Rep. Dr. David Weldon, saw his Senate confirmation hearing canceled an hour before it was to begin in March 2025, reportedly due to insufficient support. The White House then nominated Susan Monarez, who was confirmed but ousted in less than a month over policy disagreements. Several key CDC scientific leaders resigned in protest, saying Monarez's dismissal dashed hopes of shielding the agency from political interference.
Since then, multiple HHS officials have served as acting director. NIH Director Jay Bhattacharya has overseen the CDC since February. Last month, Trump nominated Dr. Erica Schwartz, a former deputy surgeon general, as the next CDC director, pending Senate confirmation.
Current and former CDC employees report a void in experienced public health leadership, with Kennedy's aides slowing or blocking the agency's ability to communicate with the public and conduct science-based work. HHS officials have countered that the CDC's critical functions remain "intact and effective," and changes aim "to restore credibility through transparency, gold standard science, and accountability."
Jernigan, who resigned from a senior CDC role last August that remains unfilled, noted the lack of a "strong, present CDC director" to advocate for funding, hiring, and retention of skilled scientists. During the hantavirus outbreak, the CDC deployed teams for evacuations and quarantines, and Bhattacharya appeared on Fox News to urge calm—but he got some details wrong and overstated what was known. Jernigan called for more career scientists to speak publicly: "That will do more for trust and for calming the nerves of the U.S. right now."
Shifting Messaging and Political Dynamics
Leadership turmoil comes as HHS and the White House have shifted focus to health initiatives related to diet, lifestyle, and affordability ahead of the midterm elections, moving away from Kennedy's initial push to roll back vaccine guidelines. While Kennedy once boasted of picking his own deputies, recent administration picks suggest his close allies may no longer be favored. For instance, after withdrawing a surgeon general nominee tied to Kennedy's Make America Healthy Again movement, Trump nominated Dr. Nicole Saphier, a radiologist and former Fox News personality who has advocated vaccines more forcefully and criticized HHS actions as "embarrassing." She requires Senate confirmation.
Despite the leadership vacuum, Kennedy remains a prominent voice for all health agencies. Jernigan expressed concern that Kennedy's decisions are driven by ideology rather than science. "The driver for the secretary is the ideology," he said. "And that's not a strategy for really improving the health of Americans."
