US FDA gearing up for rapid review of potential Covid-19 booster shots

The US Food and Drug Administration is planning a rapid review process for quick turnaround of new Covid-19 booster shots if variants of the coronavirus emerge against which the vaccines do not provide protection, the agency's top official said on Thursday.

Dr Janet Woodcock, acting commissioner of the FDA, said that if new variants of the coronavirus emerge that require booster shots or changes to vaccines, the agency will not require the type of large trials that were required for emergency use authorization or approval.

The agency plans to issue a proposal on the process for public comment in a few weeks, she said during a press briefing. That process will likely require safety information as well as, if possible, the convening of an outside committee of experts to review the booster shot.

Both Pfizer Inc and German partner BioNTech SE as well as Moderna Inc, whose vaccines have been authorized for emergency use in the United States, have said they are preparing for the possibility that variants will emerge that could require a booster shot.

The current vaccines still provide adequate protection against existing variants of concern, Woodcock said. A variant in the U.K. has been found to be more transmissible while some vaccines have been found to be less effective against variants that emerged in South Africa and Brazil.

Settling on a regulatory process will help the FDA move quickly if needed, she said.

"If the virus changes, we are getting prepared for that," Woodcock said.

The threshold for deciding on whether a new vaccine is needed has not yet been determined. Countries must build surveillance measures to find variants of concerns, and then scientists must agree upon at what point a variant has strayed too far from the unaltered virus and requires a new vaccine.