Dr. Vinay Prasad had been serving as the FDA's director of the Center for Biologics Evaluation and Research since May, and was later named chief medical and scientific officer.

During his first term, Trump signed the “Right to Try” law, which allows terminally ill patients to seek treatments that haven't been fully approved by the FDA, the AP said. His team also recently rejected three applications for new gene therapies from smaller biotech companies.

The U.S. Food and Drug Administration's top vaccine official, Vinay Prasad, has left the agency after just three months as Director of the Center for Biologics Evaluation and Research, a government spokesperson said.