Booster shots are ready for Georgians. Shortly after midnight Friday, Rochelle Walensky, director of the Centers for Disease Control and Prevention, ended a week of debate and votes and gave the final green light. Many—perhaps most—adults who got the Pfizer shots at least six months ago are now eligible.

Walgreens and CVS say as of Friday afternoon they are now giving booster shots to those eligible. They advise people to make appointments first. The Georgia Department of Public Health will start giving the shots Monday. Hospitals and clinics are gearing up, too.

The federal Centers for Medicare and Medicaid Services announced Friday that approved booster shots would be free, just like the original vaccines.

“I think it’s great news,” said Dr. Melissa Black, who treats homebound and elderly patients in metro Atlanta. “The vast majority of my patients are already vaccinated and I have been getting requests for two weeks.”

The CDC’s final order capped off a week of heated arguments over what groups should get the booster shot—or if anyone should get it, considering that the far graver problem is people who aren’t vaccinated at all.

Here’s who qualifies:

The “should” groups—CDC wants these groups to get the shot:

  • Anyone 65 years of age or older should get a booster shot.
  • Anyone in a long-term care facility should.
  • Anyone 50 years old to 64 who has underlying medical conditions should.

The “may” groups—CDC says these groups “may” get the shot. But they should consider whether the benefits outweigh the risks. The reason for this is that these younger groups are usually so well protected already by the first two shots that a booster shot might be wasted on them.

  • People 18 to 49 years old with underlying medical conditions can get the third shot.
  • People 18 to 64 years old who are at increased risk “because of occupational or institutional setting” can, too.

The decisions about booster shots only concern people who got the Pfizer vaccine. The scientists charged with setting guidelines weren’t ready to discuss whether Moderna and J&J recipients can mix and match with the booster.

Many scientists are concerned that promoting boosters will divert attention from the most important task: trying to get unvaccinated people in for shots. Others argued that it was important to widely open access to boosters, so the most vulnerable would find them easier to get.

Over the course of meetings with the Food and Drug Administration and the CDC’s Advisory Committee on Immunization Practices this week, heated arguments broke out.

The most contentious disagreement concerned opening up booster shots to adults who encounter a lot of people in their work or institutional settings. While the obvious beneficiaries in that group would be health care workers, opponents argued that that language essentially opened the shots to any adult. The downside would be that all across the country well-protected young people who don’t need a booster would get one anyway, unnecessarily adding more stress to the health system.

So the ACIP members in a split vote decided to oppose giving the shots to the younger group of workers. Hours later, Walensky overruled them.

“As CDC Director, it is my job to recognize where our actions can have the greatest impact,” she said. “In a pandemic, even with uncertainty, we must take actions that we anticipate will do the greatest good.”