WASHINGTON — Dr. Vinay Prasad, the Food and Drug Administration’s vaccine chief, is leaving the agency again, marking his second departure in under a year after a series of contentious decisions over vaccines and specialty drugs for rare diseases.
FDA Commissioner Marty Makary told staff in a late-Friday email that Prasad will depart at the end of April and return to his academic position at the University of California, San Francisco.
Prasad was briefly forced out in July after clashes with biotech executives, patient advocacy groups and conservative allies of President Donald Trump. He was reinstated in less than two weeks with the backing of Health Secretary Robert F. Kennedy Jr. and Makary.
His latest exit follows several high-profile disputes during FDA reviews of vaccines, gene therapies and other biotech products, in which the agency has in some cases reversed prior positions or asked companies to run new trials. Over the past month, Prasad faced criticism from pharmaceutical executives, investors and members of Congress for multiple agency actions.
One notable episode involved Moderna’s experimental flu vaccine built on mRNA technology. The agency initially declined to accept Moderna’s application for review — an uncommon move that prompted Moderna to publicly challenge the decision. Days later, the FDA reversed itself and agreed to review the vaccine, contingent on an additional study from the company.
More recently, the FDA and a small firm developing a gene therapy for Huntington’s disease engaged in a public and unusual dispute. UniQure said the agency demanded a new, sham‑controlled surgical trial for its brain‑injected therapy, a requirement the company said contradicted prior guidance and raised ethical concerns. The FDA held a press briefing to defend its stance and criticized the company’s original study; a senior FDA official, speaking on background, called the data “stone cold negative” and said the product had failed to demonstrate effectiveness.
Prasad’s tenure as the agency’s top vaccine and biotech regulator has been characterized by repeated clashes with the companies it oversees. More than half a dozen drugmakers working on therapies for rare or difficult‑to‑treat conditions have received rejection letters or requests for additional trials, moves that can add years and substantial costs to development programs.
A long‑time academic and outspoken critic of the FDA’s historical standards for drug approval, Prasad joined Makary in announcing measures intended to speed and simplify FDA reviews. At the same time, he has required new warnings and additional studies for certain biotech products and vaccines — including COVID‑19 shots that have been targeted by Kennedy, who had been an anti‑vaccine activist prior to joining the administration.
