U.S. Food and Drug Administration (FDA) officials say the agency is developing plans for evaluating changes to the approved COVID-19 vaccines to make them more effective against new strains of the coronavirus.
Peter Marks, MD, PhD, director of the FDA Center for Biologics Evaluation and Research, said the agency is aiming to be “nimble” in evaluating tweaks to approved vaccines to improve efficacy against emerging mutations. The FDA will require results from some small studies, but not the large trials it required for the initial vaccine approvals, which took manufacturers months to recruit and complete. Guidance for vaccine developers regarding coronavirus variants will be released in the coming weeks. In addition, the FDA’s advisory committee will likely convene before authorizing any changes to existing vaccines.
“The situation is very fluid [but] we think there are things short of doing full-fledged efficacy trials that we can use to shift or perhaps add components to existing vaccine,” acting FDA Commissioner Janet Woodcock, MD, told NPR.
So far, three variants (from Brazil, the U.K., and South Africa) have been identified in the U.S. As of February 10, the Centers for Disease Control and Prevention had reported more than 900 confirmed cases of infection with coronavirus variants in the U.S., with the most prevalent being the U.K. strain. The Pfizer/BioNTech and Moderna vaccines are still “quite effective” against the U.K. variant, according to National Institute of Allergy and Infectious Diseases head Anthony Fauci, MD.
“We should get ready for this, get ready for the fact that these variants may become more resistant,” said Paul Offit, MD, a member of the FDA advisory committee on vaccines. “If you see people who are fully immunized with these vaccines – let’s say the mRNA vaccines – that nonetheless, when infected with the variant, are being hospitalized, that’s when the line gets crossed. And to date, that has not happened.”