WASHINGTON (AP) — The Food and Drug Administration’s embattled vaccine chief, Dr. Vinay Prasad, is once again leaving the agency — the second time in less than a year that he’s departed after controversial decisions involving the review of vaccinations and specialty drugs for rare diseases. FDA Commissioner Marty Makary announced the news to FDA staff in an email late Friday, saying Prasad would depart at the end of April. Makary said Prasad would return to his academic job at the University of