The Food and Drug Administration said Thursday it had advised drugmakers to update the Covid vaccines to target the KP.2 strain, a descendant of the highly contagious JN.1 variant that began circulating widely in the U.S. this winter. The announcement came just over a week after an FDA advisory panel voted unanimously to recommend that the Covid vaccines for the fall be updated to target the JN.1 variant or one of its descendants.
2 accounts for 22.5% of new Covid cases in the U.S. KP.3, a sister variant, accounts for 25% of new cases. The FDA’s decision will allow drugmakers to begin producing and distributing the shots, which are expected to be used as part of a fall Covid vaccine campaign. Three drugmakers are producing Covid vaccines: Pfizer, Moderna and Novovax. Pfizer's and Moderna's vaccines are mRNA-based, while Novavax's is protein-based.