New COVID vaccines are coming. Here’s what to know.

The Food and Drug Administration approved updated COVID-19 vaccines Thursday, paving the way for the shots to soon land in pharmacies, doctors’ offices and health centers. The Centers for Disease Control and Prevention has said it will recommend that adults and children six months and older get updated vaccines. Here’s what to know.

How are the new shots different?

The FDA approved one vaccine from Pfizer and one from Moderna. Representatives from the drug companies said their shots were ready to ship immediately after approval.

Both vaccines target KP.2, a strain of the coronavirus that started to spread widely this spring. The variants that are most prevalent in the United States right now are very similar to KP.2, and so the vaccines should protect against them.

“When the match is very good, as we anticipate it would be with the current circulating strains, you get actual protection from infection for several months,” said Dr. Paul Sax, clinical director of the division of infectious diseases at Brigham and Women’s Hospital in Boston.

The vaccine that rolled out last fall, by contrast, was geared toward an older variant that has since petered out.

Biotechnology company Novavax is waiting for the FDA to authorize its retooled vaccine, which will target JN.1, a variant that is also close to the strains circulating widely now.

What if I just got a vaccine?

If you received a dose of the older vaccine this summer, you may not be able to get an updated vaccine immediately — the shots need to be spread out.

People who are at high risk of developing severe disease should talk with a health care provider about the ideal interval between vaccines, said Fikadu Tafesse, a virologist at Oregon Health & Science University.

What if I just had COVID?

If you’re one of the many Americans who was infected during the summer, you may want to wait a few months to get a new shot. Rushing out to get one right after you were ill won’t give you much of an added benefit, because you already have strong protection, said Aubree Gordon, an infectious disease epidemiologist at the University of Michigan. The CDC has previously said that people can wait three months after a COVID infection to get a vaccine.

How fast does protection kick in?

It takes around a week or two after getting vaccinated for antibodies to rev up and defend against the virus. Antibodies peak about a month after vaccination, Gordon said.

Once you are vaccinated, you have a lower risk of infection for at least several weeks, said Dr. Peter Chin-Hong, an infectious disease specialist at the University of California, San Francisco. “It might even be longer than that,” he said, because the vaccines are so closely matched to the dominant variants that are currently circulating.

And the vaccines will provide protection against the worst outcomes from COVID — developing severe disease, getting hospitalized and dying — for months.

When should I get vaccinated?

People who are at highest risk for severe disease, including those who are 65 and older, people who are immunocompromised and those with underlying medical conditions, should get the updated vaccines as soon as they are available, Sax said.

“There’s a lot circulating in the community now — that would help protect them,” he said.

People who are not at high risk may want to wait until October, Chin-Hong said, both to gain protection heading into the winter and holiday gatherings, and so that they can get flu shots at the same time.

“Convenience trumps everything,” he said.

Can I get it for free?

Many private insurance plans, along with Medicare and Medicaid, cover the cost of COVID shots. And children can receive free vaccines through a federal program. The CDC’s Bridge Access Program, which has provided about 1.5 million free COVID shots to uninsured and underinsured people, will not be renewed for this year. But Dr. Demetre Daskalakis, director of the CDC’s National Center for Immunization and Respiratory Diseases, said the agency had found $62 million in unused vaccine contract funding that would be sent to state and local immunization programs to help cover the cost of shots.