The U.S. Food and Drug Administration (FDA) has revised its strain recommendation for the 2024-25 COVID-19 vaccines, advising manufacturers to update their shots to target the KP.2 variant if feasible, instead of the previously recommended JN.1 lineage.
This update comes as Moderna and Novavax, two of the three COVID-19 vaccine producers, submitted their applications for updating the fall 2024 vaccines with the JN.1 strain. Novavax, currently manufacturing the JN.1 vaccine, stated it would not be able to produce a shot for another strain this fall. The company, which applied for authorization last week, reported that its JN.1 shot showed broad cross-neutralizing antibodies against multiple variants, including KP.2 and KP.3, and would be ready by mid-July.
Novavax has yet to comment on the FDA’s preference for a KP.2 targeted vaccine. The FDA’s new guidance diverges from the recommendations of its own advisers, as well as those of the European regulator and the World Health Organization (WHO), all of which supported targeting the JN.1 strain with the updated vaccines.
Earlier this year, JN.1 was the dominant strain in the U.S., but it has since declined in prevalence, accounting for only 3.1% of cases over a two-week period ending June 8, according to the Centers for Disease Control and Prevention (CDC). In contrast, the KP.2 variant was estimated to account for 22.5% of cases, with KP.3 now being the dominant variant at 25%.
As reported by ExpressPharma, Pfizer announced on June 14, 2024 that it was in discussions with global regulators, including the FDA, to evaluate the composition of future COVID-19 vaccine formulations. Moderna has indicated that it will be ready with the updated shot in time for the fall vaccination campaign, regardless of the final strain decision.