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 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.

In a major policy shift, federal health officials anticipate the shots will be made available to adults 65 and older as well as children and younger adults who have one or more risk factors that make them more vulnerable to severe COVID-19.