US President Joe Biden has called for booster shots, or booster shots, for the elderly and vulnerable who have received the Pfizer vaccine for COVID-19.

"The booster shots are free and easily accessible," Biden said in a speech at the White House on the 24th local time.

60 million Americans are targeted by President Biden's booster shot, and he explained that there will be a booster shot opportunity in the case of Moderna and Janssen vaccines.

The U.S. Centers for Disease Control and Prevention (CDC) previously approved Pfizer vaccine boostershots for people 65 years of age or older, nursing home residents, and people with underlying medical conditions.