The US Food and Drug Administration is changing the way it approves Covid-19 vaccines for Americans, a move that may limit future shots to older Americans and people at higher risk of serious Covid-19 infection.

The agency will narrow its approval for updated coronavirus vaccines, marking a significant shift in the agency’s approach to green-lighting shots that have been recommended broadly to the public.

The U.S. Food and Drug Administration approved Novavax's COVIDd-19 vaccine with age restrictions after a six-week delay.