Booster shots may be needed after COVID-19 vaccines - U.S. official

The United States is preparing for a possibility that a booster shot could be needed between nine to 12 months after a COVID-19 vaccine, a White House official said on Thursday.

While the duration of immunity after vaccination is being studied, it is possible that vulnerable populations may need to get a booster shot first, said David Kessler, chief science officer for President Joe Biden's COVID-19 response task force.