U.S. health regulators on Monday granted full approval to Moderna’s COVID-19 vaccine, a shot that’s already been given to tens of millions of Americans since its emergency authorization over a year ago.

The action by the Food and Drug Administration means the agency has completed the same rigorous, time-consuming review of Moderna’s shot as dozens of other long-established vaccines.

The decision was bolstered by real-world evidence from the more than 200 million doses administered in the U.S. since the FDA cleared the shot in December 2020. The FDA granted full approval of Pfizer’s vaccine last August.

Public health advocates initially hoped the regulatory distinction would boost public confidence in the shots. But there was no discernable bump in vaccinations after the Pfizer approval, which was heavily promoted by President Joe Biden and other federal officials. Still, regulators said Monday they hoped the extra endorsement would encourage more people to get vaccinated.

More than 211 million Americans, or 63% of the total population, are fully vaccinated. About 86 million people have gotten a booster dose. Vaccinations peaked last spring at more than 3 million per day and now average less than 750,000 per day. The pace of vaccinations briefly spiked following news of the omicron variant in December but has since slowed again.

In the U.S., Moderna is used only by adults, for initial vaccination and as a half-dose booster. The company said last fall that FDA had delayed deciding whether to clear the shots for 12 to 17 years as it examined the heart inflammation risk.

Johnson & Johnson has not yet applied for full approval of its COVID-19 vaccine.

Also Monday, Novavx Inc. formally requested FDA authorization of a different type of COVID-19 vaccine, in hopes of becoming the fourth U.S. option.