The Food and Drug Administration on Friday approved the Novavax Covid-19 vaccine, but only for older adults and for others over age 12 who have at least one medical condition that puts them at high risk from Covid.

Scientific advisers to the Centers for Disease Control and Prevention, who typically make decisions on who should get approved shots and when, have been debating whether to recommend Covid shots only to the most vulnerable Americans. The F.D.A.’s decision appeared to render at least part of their discussion moot.

The new restriction will sharply limit access to the Novavax vaccine for people under 65 who are in good health. It may leave Americans who do not have underlying conditions at risk if a more virulent version of the coronavirus were to emerge. It could also limit options for people who want the vaccine for a wide array of reasons, including to protect a vulnerable loved one.

WASHINGTON (AP) — Novavax’s closely watched COVID-19 vaccine is on track for full approval after additional discussions with the Food and Drug Administration, the company said Wednesday.

The news sent company shares soaring more than 21% in morning trading and appeared to resolve concerns that Trump administration officials might be holding up a decision on the shot.