Where to find a COVID booster (and more booster questions, answered)

A pharmacist gets ready to give a COVID-19 booster.
Safeway pharmacist Shahrzad Khoobyari (left) prepares to give a Pfizer COVID-19 booster vaccination to Chen Knifsend (right) on Oct. 1 in San Rafael, Calif. The U.S. has opened COVID-19 booster shots to all adults.
Justin Sullivan | Getty Images

Updated: 6:02 a.m. Nov. 22 | Posted: 5 a.m. Nov. 18

The U.S. has opened COVID-19 booster shots to all adults and is urging people 50 and older to seek one, aiming to ward off a winter surge as coronavirus cases rise even before millions of Americans travel for the holidays.

Under the new rules, anyone 18 or older can choose either a Pfizer or Moderna booster six months after their last dose. For anyone who got the single-dose Johnson & Johnson vaccine, the wait already was just two months. And people can mix-and-match boosters from any company.

While all three vaccines used in the U.S. continue to offer strong protection against severe COVID-19 illness and death, the shots’ effectiveness against milder infection can wane over time.

Here are a few things to know about boosters and why health officials are urging people to get them.

Why do I need a booster? I'm already fully vaccinated.

People who are fully vaccinated are still strongly protected against hospitalization and death from COVID-19. But immunity against infection can wane over time, and the extra-contagious delta variant is spreading widely.

The CDC recommends that all adults 18 years old and older who had the single J&J shot should get a booster of any of the three vaccines.

U.S. health authorities want to shore up protection in at-risk people who were vaccinated months ago, though the priority remains getting the unvaccinated their first shots.

Where can I get a booster?

You can sign up to get a booster shot at health clinics and pharmacies like Walgreens and CVS — the same places that are administering first and second doses. They remain free.

Are COVID-19 boosters the same as the original vaccines?

Yes, boosters use the same recipe as the original shots, despite the emergence of the more contagious delta variant. The vaccines weren’t tweaked to better match delta because they’re still working well.

The vaccines work by training your body to recognize and fight the spike protein that coats the coronavirus and helps it invade the body’s cells. Delta’s mutations fortunately weren’t different enough to escape detection.

The increased protection you might get from a booster adjusted to better match the delta or other variants would be marginal, says Dr. Paul Goepfert, director of the Alabama Vaccine Research Clinic at the University of Alabama at Birmingham.

Manufacturing doses with a new formula would have also delayed the rollout of boosters.

Moderna and Pfizer are studying boosters tweaked for the delta and other variants to be ready if one’s ever needed. Health authorities would have to decide if and when a vaccine formula swap would be worthwhile.

Can I 'mix and match'?

Federal health officials have signed off on allowing the flexibility of “mixing and matching" that extra dose regardless of which type people received first.

A CDC panel didn't explicitly recommend anyone get a different brand than they started with but left open the option — saying only that a booster of some sort was recommended. Preliminary results of a government study found an extra dose of any vaccine triggered a boost of virus-fighting antibodies regardless of what shots people got to begin with.

People sit in chairs after getting their COVID-19 booster shot.
A patient takes a selfie with their vaccination card in the observation area after receiving their COVID-19 booster during a vaccination clinic in Southfield, Mich.
Emily Elconin | Getty Images

Are the boosters safe?

Yes. "There's very, very little risk," of any serious complications from a booster shot, says Desi Kotis, associate dean at the University of California, San Francisco School of Pharmacy. It's reasonable to assume the "booster could show about the same side effects that you had after those first or second series shots."

Can I get the flu and COVID-19 vaccines at the same time?

Yes, you can get the shots in the same visit.

The CDC and other health experts point to past experience showing that vaccines work as they should and any side effects are similar whether the shots are given separately or in the same visit.

“We have a history of vaccinating our kids with multiple vaccines,” says flu specialist Richard Webby of St. Jude Children’s Research Hospital.

Staying up to date on all vaccinations will be especially important this year, experts say.

Since people were masked and staying home, last year’s flu season barely registered. This year, it’s unclear how intense the flu season will be with more places reopened.

“The worry is that if they both circulate at the same time, we’re going to have this sort of ‘twin-demic,’” Webby says. “The concern with that is that it’s going to put extra strain on an already strained health care system.”

One caution: COVID, colds and flu all share similar symptoms so if you feel ill, the CDC says to postpone a vaccination appointment until you’re better to avoid getting others sick.

Will this be my last booster?

Nobody knows. Some scientists think eventually people may get regular COVID-19 shots like annual flu vaccinations. But researchers will need to study how long protection from the current boosters lasts.

I’m immunocompromised. What booster shot should I get?

Dr. Abinash Virk, infectious disease specialist at Mayo Clinic in Rochester, Minn., recommends that if immunocompromised individuals initially received the J&J vaccine, they should get the full series of Pfizer or Moderna, instead of just a six-month booster.

People who completed the full series can get a Pfizer or Moderna booster shot.

I had COVID-19. How will a booster affect me?

A booster shot “is unlikely to aggravate the long COVID,” says Virk. “We recommend getting the booster.”

As for breakthrough COVID-19 cases, she says, protection from natural infection lasts three to four months so getting a booster shot is still recommended.

Why aren’t teens getting boosters yet?

Studies have not been done yet regarding boosters for children under 18. Unless they are immunocompromised, boosters aren’t yet recommended for them.

Now that children ages 5 to 11 are getting the vaccine, is there enough supply for adults to get boosters, too?

Yes, says Virk, adding that “at this moment, it seems that we do have an ample supply of boosters as well as primary doses.”

OK, I got a booster. Can I stop wearing a mask?

Charlotte Baker, an assistant professor of epidemiology at Virginia Tech, and Dr. Abraar Karan, an infectious disease doctor at Stanford University, urge you to keep your stash of masks.

With cold and flu season ramping up, wearing a mask when you're out and about can protect you from a variety of germs.

What questions do you have about COVID-19 boosters?

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