The Johnson & Johnson shot is seen as a critical vaccine for poorer countries. But late last year, the company paused production at the only plant making usable batches of the vaccine.
The FDA is still lacking a Senate-confirmed leader, but the agency is at the center of several major policy battles. Lawmakers this year must renew the bill that authorizes drug companies to pay "user fees," which enable the agency to hire additional reviewers to speed the approval of drugs.