WASHINGTON — The Biden administration announced that Americans who have been fully vaccinated against COVID-19 should receive a booster shot to ensure continued protection, according published reports.

The plan, which is still being developed, would involve administering third shots beginning in mid- to late September, one source added, pending authorization from the US Food and Drug Administration. Pfizer and BioNTech said Monday that the companies have submitted initial data to the FDA to support the use of booster doses for their COVID-19 vaccines.

The plan could be announced in the coming weeks. Until now, federal health officials have said boosters are not needed by the general population. Last week, the FDA authorized third doses for some people who are immunocompromised and the US Centers for Disease Control and Prevention almost immediately recommended giving those doses.