WASHINGTON (NewsNation Now) — The U.S. Food and Drug Administration gave full approval to Pfizer’s COVID-19 vaccine on Monday, a milestone that may help lift public confidence in the shots as the nation battles the most contagious coronavirus mutation yet.

The approval could boost the vaccination campaign by convincing more unvaccinated Americans that Pfizer’s shot is safe and effective and also make officials more comfortable implementing vaccine mandates.

Vaccine hesitancy has been a major hurdle to the White House’s goal of getting all eligible Americans vaccinated against the coronavirus.

“While millions of people have already safely received COVID-19 vaccines, we recognize that for some, the FDA approval of a vaccine may now instill additional confidence to get vaccinated. Today’s milestone puts us one step closer to altering the course of this pandemic in the U.S.,” said Acting FDA Commissioner Janet Woodcock, M.D.

President Joe Biden praised the move by the FDA, adding that he hopes this allows more businesses to require COVID-19 vaccines.

“With today’s full FDA approval, there’s another good reason to get vaccinated,” he said during remarks Monday.

U.S. vaccinations bottomed out in July. But, as the delta variant fills hospital beds, shots are on the rise again — with a million a day given Thursday, Friday and Saturday.  Just over half of the U.S. population is fully vaccinated with one of the country’s three options, from Pfizer, Moderna or Johnson & Johnson.

The U.S. is the first country to fully approve the shot, according to Pfizer, and CEO Albert Bourla said in a statement he hoped the decision “will help increase confidence in our vaccine, as vaccination remains the best tool we have to help protect lives.”

Full approval of Pfizer’s shot now makes it easier for physicians to prescribe a third booster shot to people who could benefit from an additional dose.

The FDA is already allowing emergency use of a third dose of either the Pfizer or Moderna vaccine for people with severely weakened immune systems, such as organ transplant recipients who don’t respond as strongly to the usual two shots. For everyone else who got those vaccinations, the Biden administration is planning ahead for booster starting in the fall — if the FDA and CDC agree.

Dr. Timothy Quinn discusses vaccine hesitancy amid FDA approval of the Pfizer vaccine.

Some experts, including at the World Health Organization, say there is not yet enough data to be certain that boosters are needed.

Pfizer’s vaccine was authorized for emergency use in December, and more than 203 million people in the United States have so far received it. The Pentagon said Monday that it will issue guidance to make vaccines mandatory for the military now that the Pfizer vaccine is approved.

The Associated Press contributed to this report.