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.

The U.S. Food and Drug Administration on Tuesday said it plans to require new clinical trials for approval of annual COVID-19 boosters for healthy Americans under age 65, effectively limiting them to older adults and those at risk of developing severe illness.

The Food and Drug Administration will issue new guidelines requiring stiffer clinical trials prior to the approval of new COVID boosters.