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 FDA plans to require new clinical trials for approval of annual COVID-19 boosters for healthy Americans under 65.

The rollout of updated Covid vaccines for healthy children and adults this fall is likely to be delayed after the FDA said it will require another clinical trial.