COVID Booster Shots for All Americans, Starting Sept. 20 WEDNESDAY, Aug. 18, 2021 -- After concluding that a third dose of a coronavirus vaccine is needed to fight off waning immunity in the fully vaccinated, the Biden administration said Wednesday it will begin offering booster shots to all Americans starting Sept. 20. The plan, which only involves the Pfizer and Moderna vaccines at this point, calls for Americans to get a booster shot eight months after their second dose. The officials said they expect a booster shot will be needed for people who received the Johnson & Johnson vaccine, but...