The U.S. Food and Drug Administration approved Novavax's COVID-19 vaccine, but limited its use to older adults and people over the age of 12 with conditions that put them at risk due to the illness. The vaccine's prospects were thrown into doubt after the FDA missed its April 1 target to approve the shot,

The agency narrowed who can get the shot and added new study requirements that could cost the company tens of millions.

After a six-week delay, the US Food and Drug Administration has approved Novavax’s Covid-19 vaccine, according to a letter from the agency, but only for people 65 and older and those 12 and up who have at least one underlying condition that puts them at higher risk of severe illness.