The country’s top vaccine official dramatically quit his job late Friday, making public a blistering resignation letter targeted at anti-vax HHS Secretary RFK Jr.
Dr. Peter Marks was the Food and Drug Administration official who played a key role in the development of COVID-19 vaccines during the first Trump presidency—but he quit after being told if he did not resign, he would be fired.
The letter suggests a crisis of confidence in Kennedy—a long-time vaccine skeptic who has spread bogus claims about their safety and advocated unsafe alternative treatments for dangerous conditions—at the top of the department he runs.
In his resignation letter, addressed to acting FDA Commissioner Sara Brenner, Marks wrote, “It has become clear that truth and transparency are not desired by the Secretary, but rather he wishes subservient confirmation of his misinformation and lies,” referring to newly installed Health and Human Services Secretary Robert F. Kennedy Jr.
He continued, “My hope is that during the coming years, the unprecedented assault on scientific truth that has adversely impacted public health in our nation comes to an end.”
In response to his resignation letter, an HHS spokesperson said, “If Peter Marks does not want to get behind restoring science to its golden standard and promoting radical transparency, then he has no place at [the] FDA under the strong leadership of Secretary Kennedy.”
Marks had served as the director of the Center for Biologics Evaluation and Research since 2016, and had been working at the FDA since 2012.
He played an important role in establishing Operation Warp Speed, the program designed to oversee the development, manufacture, and distribution of COVID-19 vaccines, although he left shortly after its launch, instead focusing on his work as chief regulator of vaccines.
Marks is the third top FDA official to leave the agency this year, following the resignations of Dr. Patrizia Cavazzoni, the director of the FDA’s Center for Drug Evaluation and Research, and Jim Jones, head of the food division.
Kennedy has been widely criticized for his stance on vaccines; most recently, he hired a discredited skeptic known for attempting to draw a link between vaccinations and autism as a senior data analyst at the HHS. In addition, since becoming health secretary, Kennedy has paused vaccine contracts, described vaccination as a “personal decision,” and downplayed a measles outbreak in Texas and New Mexico, calling it “not unusual,” before later clarifying that combating the outbreak was a “priority” for his department. In 2024, there were a total of 285 reported cases of measles in the United States; in the first three months of 2025 alone, there have been 483 reported cases.
In November, Kennedy declared that President Donald Trump would remove fluoride from drinking water if elected. On Thursday, Utah became the first state to ban fluoride in public drinking water, despite opposition from dentists and health experts.
Also on Thursday, Kennedy announced that the HHS would slash 10,000 full-time jobs across a number of departments, including those responsible for responding to disease outbreaks, drug approvals, and health insurance. Thursday’s layoffs are in addition to the roughly 10,000 employees who have already opted for voluntary resignation this year, bringing the total size of the department down from 82,000 to 62,000 full-time employees.
In a press release issued on Thursday, Kennedy declared, “We aren’t just reducing bureaucratic sprawl. We are realigning the organization with its core mission and our new priorities in reversing the chronic disease epidemic.” He continued, “This Department will do more—a lot more—at a lower cost to the taxpayer.”
