Pfizer Inc has requested the authorization of its booster shots by the Food and Drug Administration for all Americans who are aged 18 years and older.

This comes after a third dose of the vaccine, developed with German partner BioNTech, has received authorization by the FDA for older people and those who are at-risk adults, six months after they complete their primary or initial series of shots.

The Moderna vaccine booster shots have also been given the green light for the at-risk adults and elderly people while a second shot of Johnson & Johnson’s vaccine has been cleared for all adults. According to data compiled by the Centers for Disease Control and Prevention, more than 25 million Americans have received an additional dose of one of the three vaccines as of Monday.

The drugmaker, Pfizer, has asked the agency to amend its authorization after data based on more than 10,000 individuals shows that the booster dose is safe and effective.

The World Health Organization, for a while, has been urging wealthy countries to hold off on distributing boosters shots while some scientists say they do not agree that most Americans need boosters at the moment.

In August, President Joe Biden said boosters were going to be rolled out to all adults as early as September.

However, an influential FDA advisory committee later rejected that proposal, paring back those plans to unanimously recommend the third shots to people age 65 and older and other vulnerable Americans.