As Dec. 2, 2020, photo provided by Johnson & Johnson shows vials of the Janssen COVID-19 vaccine in the United States. Johnson & Johnson’s single-dose vaccine protects against COVID-19, according to an analysis by U.S. regulators Wednesday, Feb. 24, 2021, that sets the stage for a final decision on a new and easier-to-use shot to help tame the pandemic. The Food and Drug Administration’s scientists confirmed that overall, it’s about 66% effective and also said J&J’s shot, one that could help speed vaccinations by requiring just one dose instead of two, is safe to use. (Johnson & Johnson via AP)