The Food and Drug Administration authorized booster shots for seniors, younger adults with underlying health conditions and those in jobs that put them at high risk for COVID-19 Wednesday night.

Those jobs include health care workers, teachers, grocery workers and those in homeless shelters and prisons. Under FDA authorization, those individuals would be eligible for booster shots six months after receiving their second Pfizer shot.

In a press release, the FDA said booster shots “may be effective in preventing COVID-19 and that the known and potential benefits of a booster dose outweigh the known and potential risks” for seniors and those at risk.

“Today’s action demonstrates that science and the currently available data continue to guide the FDA’s decision-making for COVID-19 vaccines during this pandemic,” Acting FDA Commissioner Dr. Janet Woodcock said. “As we learn more about the safety and effectiveness of COVID-19 vaccines, including the use of a booster dose, we will continue to evaluate the rapidly changing science and keep the public informed.”

The FDA’s decision on booster shots for seniors and those at risk came just under a week after an advisory committee met to get input from public health officials on the data Pfizer had submitted.

“We’re grateful for the advice of the doctors, scientists, and leading vaccine experts on our advisory committee and the important role they have played in ensuring transparent discussions about COVID-19 vaccines,” FDA’s Center for Biologics Evaluation and Research Director Dr. Peter Marks said.

The FDA decision does not mean seniors and those at risk can get the vaccine quite yet. Advisers to the Centers for Disease Control and Prevention opened a two-day meeting Wednesday to make their own, more specific recommendations about who should get the extra shot and when. A vote is expected later Thursday.

It’s also important to note the current regulatory discussion is focused on the Pfizer vaccine. Regulators will decide at a later date on boosters for the Moderna or Johnson & Johnson vaccines. People who got either of those vaccines initially would not be eligible for a Pfizer booster.