As infections rise, Americans over 18 will be permitted to get extra doses. But it’s not clear boosters really are needed by so many people, or that the shots will turn back the pandemic.
With the agency director’s sign-off, children ages 5 to 11 could begin to receive the shots this week.
Dr. Nkengasong will be the first person of African origin to oversee the U.S. government program combating H.I.V., which has ravaged the continent.
The benefits of a third shot for most people are small and are far outweighed by the benefits of using those doses for initial vaccinations, the scientists say.