The Food and Drug Administration says it has decided to continue approving COVID-19 vaccine updates for seniors and others at higher risk of severe disease, but will require vaccine makers to conduct major new clinical trials before approving them for wider use.

An FDA advisory committee unanimously recommended Thursday that the next COVID vaccine should be a monovalent one in the JN.1 lineage, although members disagreed slightly about which specific strain should be included.

The change marks a shift in the Food and Drug Administration’s policy on approving COVID-19 vaccines, which the new commissioner described as a “one-size-fits-all regulatory framework.”