On March 28, 2025, Dr. Peter Marks resigned as director of the FDA's Center for Biologics Evaluation and Research (CBER) -- the division responsible for overseeing vaccine safety and approval -- after receiving an ultimatum from HHS leadership: step down voluntarily or face termination.
Resignation Letter
In his resignation letter, Marks wrote that "truth and transparency are not desired" by HHS Secretary Robert F. Kennedy Jr. He publicly accused Kennedy of promoting "misinformation and lies" about vaccines, making him one of the most senior federal scientists to directly challenge the administration's public health leadership.
Significance
Marks had served as CBER director since 2016, playing a central role in the emergency authorization of COVID-19 vaccines and overseeing the U.S. vaccine approval process. His departure was one of the earliest and most visible signals that the Kennedy-led HHS was actively purging career scientists who defended vaccine safety data.
In an April 7 interview, Marks elaborated that he had tried to protect vaccine safety data from Kennedy's interference and was forced out for refusing to accommodate the secretary's anti-vaccine agenda. He later joined Eli Lilly in October 2025.
Context
The forced resignation came just three days after the Senate confirmed Marty Makary as FDA Commissioner, signaling that the new FDA leadership would not serve as a bulwark against Kennedy's influence. Together with the later firing of all ACIP members in June 2025, Marks' ouster represented the systematic dismantling of the institutional infrastructure that had governed U.S. vaccine policy for decades.