FDA prepares plan if vaccines prove less effective against new variants

FDA said Thursday it is preparing a plan for action in case coronavirus variants evade current COVID-19 vaccines. “If variants emerge that are not prevented, that the vaccines have poor efficacy against, then we will need to rapidly change,” said Janet Woodcock, FDA’s acting director. New versions of the vaccine would have to be quickly manufactured, tested, and distributed. As of February 4, 611 of the 618 coronavirus variant cases identified in the United States thus far have involved a variant first observed in Britain, according to CDC data. Pfizer and Moderna’s vaccine have demonstrated efficacy against known variants of the coronavirus, though they are less potent against the variant first identified in South Africa. The companies have said they are prepared to modify their vaccines as needed, and that could be accomplished in as little as 6 weeks. Although Woodcock did not say how FDA would evaluate any updated vaccines, she said FDA would likely request smaller and shorter trials than the original trials conducted by Pfizer and Moderna. If the vaccines are ineffective against a new variant, “we can’t go through more 30,000 patient trials,” she explained. “There are things short of doing full-fledged efficacy trials that we can use to shift or perhaps add components to the existing vaccines.” The plans will be released for comment from scientists prior to implementation, Woodcock said, noting FDA may also look to an advisory committee to help with any changes to existing vaccines. Additionally, FDA intends to issue guidance documents for monoclonal antibody treatments and for tests of the virus.