Since 2023, federal health officials have recommended an annual COVID-19 shot for most people, and vaccine makers have not needed to conduct additional tests on each year’s updated vaccine. It's similar to the way the annual flu shot is updated to target the newest influenza strains,

The FDA will now require clinical trials to approve boosters for healthy Americans under 65, making it unlikely the shots will reach the market.

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.