By Zachary Stieber
Contributing Writer
The Food and Drug Administration’s top vaccine official has left the agency for a second time, and his deputy has been promoted to the vacant position.
Dr. Vinay Prasad had been the director of the FDA’s Center for Biologics Evaluation and Research, which reviews applications from companies for experimental vaccines. His last official day was April 30.
Dr. Tracy Beth Hoeg, acting director of another FDA center, wrote on X that she was grateful she had the opportunity to work with Prasad, describing him as having done “transformational work at the FDA.”
Katherine Szarama, who had been CBER’s deputy director, has been elevated to acting director of the center, a spokesperson for the Department of Health and Human Services, the FDA’s parent agency, wrote in an email.
Prasad was tapped by Dr. Marty Makary, the agency’s commissioner, for an FDA leadership position in 2025, following the resignation of Dr. Peter Marks over differences with Health Secretary Robert F. Kennedy Jr.
The University of California-San Francisco professor became known during the COVID-19 pandemic as a critic of government actions, including the widespread promotion of COVID-19 vaccination for young people despite the vaccines causing heart inflammation.
Prasad exited the FDA a few months later, after supporters of President Donald Trump noted his past social media posts in favor of Democrats and progressive policies.
“He saw some media headlines and didn’t want to be a distraction,” Makary told reporters during an unrelated briefing.
Makary intervened, and Prasad returned to head CBER in August 2025.
“Neither the White House nor [the Department of Health and Human Services] will allow the fake news media to distract from the critical work the FDA is carrying out under the Trump administration,” a spokesperson for the department said at the time.
CBER is tasked with regulating biological and related products, such as vaccines and gene therapies. Its personnel review submissions and decide whether to approve or reject them, based on the risk-benefit calculus for new products.
Actions taken by CBER in recent months have drawn scrutiny from lawmakers, including some Republicans. Sen. Ron Johnson, R-Wis., has criticized the administration for declining to approve a drug called ataluren for Duchenne muscular dystrophy, a disease that causes muscle degeneration.
“It’s just incomprehensible how the FDA has been handling treatments for rare diseases,” he said.
Others have taken issue with the FDA’s decision not to approve Replimune’s drug for the treatment of skin cancer.
Kennedy told senators in April that the drug does not appear to work, citing conversations with Makary.
“I had nothing to do with this decision,” Kennedy said. “This decision comes out of FDA and we trust the process there.”
