Joe Biden said he and the first lady will inject the third vaccine to enhance immunity.

Biden, 78 years old, and Jill Biden, 70, injected the first Pfizer in December 2020, when the new vaccine was released in the US.

President Joe Biden at the White House on August 18.

Washington will inject the third vaccine for adults in the US from September 20.

Health officials explain the plan to provide additional protection for Americans, while Washington can still donate millions of doses around the world and continue to encourage everyone to inject the first.

American Disease Control and Prevention Center Rochelle Walensky said the data show that people need to be further protected in the context of Delta variant raging and the effectiveness of the decline in vaccine over time, though

The enhanced injections begin to be deployed from September 20 for those who have injected enough vaccines of Pfizer or Moderna for 8 months.