The chief vaccine regulator for the Food and Drug Administration resigned from his position and criticized the Health Secretary for prioritizing misinformation over truth and transparency in a strongly-worded resignation letter.
Peter Marks, who has been a part of the FDA since 2012, submitted his resignation on Friday, citing concerns about the administration’s vaccine efforts. The contents of his letter were made public by the Washington Post.
In his letter addressed to Sara Brenner, the Acting Commissioner of Food and Drugs, Marks mentioned his willingness to collaborate on vaccine safety with Robert F. Kennedy Jr. However, he expressed disappointment that the Health Secretary did not value truth and transparency in the matter.
Marks continued, ‘rather he [Kennedy] wishes subservient confirmation of his misinformation and lies.’
‘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 so that the citizens of our country can fully benefit from the breadth of advances in medical science,’ Marks added.
‘Though I will regret not being able to be part of future work at the FDA, I am truly grateful to have had the opportunity to work with such a remarkable group of individuals as the staff at the FDA and will do my best to continue to advance public health in the future,’ he concluded.
Marks also detailed his time serving as the Director of the Center for Biologics Evaluation and Research and praised his colleagues at the FDA.
He conceived the plan for Operation Warp Speed in March 2020, accelerating the vaccination development for COVID-19.

Peter Marks, a member of the FDA since 2012 and director of the Center for Biologics Evaluation and Research, resigned from his position on Friday

Marks’ resignation letter slammed Secretary Robert F. Kennedy Jr. for not desiring ‘truth and transparency’ on vaccines

Marks was a key part of Operation Warp Speed which detailed a plan for vaccine implementation in response to the COVID-19 pandemic
Marks was also a part of the team that responded to the mpox epidemic in 2022 and warned in his letter that a similarly rapid response would be needed to combat HVN1 in the coming years.
He advocated in the letter for the safety and importance of vaccines, detailing the history of their impact dating back to the smallpox outbreak in 1777.
Marks made sure to clarify that vaccines don’t cause autism and argued that the measles outbreak in Texas is a harsh reminder of what happens when science is undermined by public officials.
The advocacy for vaccines presents a stark contrast to Kennedy, who has frequently floated vaccine skepticism.
He has previously said that getting vaccinated was a ‘personal decision’ and dismissed the recent measles outbreak as ‘not unusual.’
Sources close to the matter revealed to the Wall Street Journal that Marks was pushed out of his position.
An official with the HHA told the publication, ‘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 FDA under the strong leadership of Secretary Kennedy.’
Another source familiar with the tension between the two told the WSJ that Marks had sent Kennedy a memo proposing listening sessions on immunizations.

Marks detailed the history of vaccines in the US in his resignation letter and advocated against the conspiracy theory that vaccinations are linked to autism

Kennedy was confirmed as Director of Health and Human Services on February 13, 2025, despite backlash on his past comments about vaccines
An anonymous source at the HHS told the Washington Post that Marks didn’t have a ‘place at the FDA’ because he didn’t share Kennedy’s vision for the agency.
Two sources who spoke with the Washington Post said that the divisions between Kennedy and Marks resulted in an ultimatum for the former director – resign or be fired.
Kennedy’s unconventional stances have caused multiple rifts in the agency, with Marks being the third official to leave the FDA this year, following the resignations of drug chief Dr. Patrizia Cavazzoni and human foods chief Jim Jones.
The secretary’s past doubts about vaccines were a point of contention during his confirmation hearing.
However, Kennedy had backpaddled the comments during his hearings and told Senator Bill Cassidy that he would boost confidence in vaccines if he were confirmed.
He added that he wouldn’t change vaccine approval systems as the secretary, which fell under Marks’ jurisdiction.
Since his confirmation, Kennedy has asked the Centers for Disease Control and Prevention to look into links between autism and vaccines, a conspiracy theory that has repeatedly been debunked.
Kennedy also announced on Thursday that 10,000 workers in the health department would be laid off.
‘I want to promise you now that we’re going to do more with less,’ he said in a social media video.

Sources close to the matter revealed to the Washington Post and the Wall Street Journal that Marks was pushed out of his position due to his differing opinions about vaccine with RFK Jr.
Medical experts have expressed concerns about Kennedy’s stances which have now been intensified with Marks’ departure.
Dr. Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia and a vaccine adviser to the FDA, told CNN that he expects Kennedy will hire officials to ‘shoehorn data’ and pedal conspiracy theories about vaccines and autism.
Dr. Ashish K. Jha, who served as the White House’s COVID-19 response coordinator in 2022 and 2023 wrote on X that Marks’ resignation is, ‘Making the FDA dramatically weaker, less effective.’
Marks will continue to serve as the director of the Center for Biologics Evaluation and Research until April 5.
DailyMail.com reached out to the FDA for comment on his resignation but did not immediately hear back.