What’s the Deal with Boosters (and Why It’s a Good Time for a Boost)

3 women holding up their vaccination cards

Have you recently been notified by your child’s school or your employer that you’ve possibly been exposed to COVID? Or have your heard from friends or family that they’ve had a positive test? If so, you aren’t alone. COVID cases are rising again. If you are eligible for a booster shot but haven’t gotten it yet, now is a perfect time to boost your protection.

Boosters keep your body’s protection against COVID-19 strong for longer, guarding against getting very sick, going to the hospital, or death. Your body develops protection from the virus from your first COVID vaccinations or if you had COVID, but that protection fades over time. And if you had COVID earlier in the pandemic, that may not provide much protection against the current variants circulating.

Boosters keep your immunity up. They are common for many vaccines, like most childhood vaccines and those that protect against the flu and hepatitis. We get the boosters to help when specific viruses change over time or when our immune system loses some of its ability to fight off a virus. Boosters help get our immune system back in shape and ready to do its job.

Booster shots have proven to be very effective in preventing serious illness from COVID. What do we mean by serious illness? Serious COVID illnesses can make you miss work or school for weeks, leave you with symptoms for months, require hospitalization or even lead to death.

As with any vaccine, boosters can’t prevent all infections. It’s possible that you could get a less serious case of COVID even after getting a booster shot. You might feel some symptoms for a few days, or you might even feel like you’ve got the flu. But boosters help prevent the most serious health threats from COVID.

How do we know? When a lot of people were getting sick with the Omicron variant of COVID-19 in early 2022, boosters kept people out of the hospitals and prevented them from dying. Adults who got a booster of Pfizer or Moderna were 94 percent less likely to be put on a ventilator or die from COVID compared to people who weren’t vaccinated.

The bottom line: boosters save lives. If you’re vaccinated but haven’t gotten your booster, you aren’t fully protected.

Your questions about boosters answered

We’ve been hearing a lot of questions about why people should bother getting a booster, so we’ve pulled together some information that can help:

Are booster doses a different vaccine from the Pfizer or Moderna vaccine I already got?

Booster shots are the same vaccine as the first doses you get of Pfizer or Moderna. A booster is another dose to keep your protection strong. The booster shots use the same type of vaccine as the first and second doses of Pfizer or Moderna.

I got the first two doses of vaccine and I already had COVID. Why should I get a booster?

We recommend booster doses for everyone who is eligible, whether or not they have been infected with COVID in the past. When you get a COVID infection, your body develops some immunity or protection. But we don’t know how long that immunity lasts. The COVID virus also changes over time, and we can’t be sure how much immunity an infection might give you against future versions (or variants).

Are we at a high enough level of vaccination that we don’t need to get boosters anymore?

Vaccination rates in King County are high, and that does make our whole region better protected. But our coverage for boosters has a long way to go. It’s so important for people who have weakened immune systems, such as older adults and people who are at high risk for severe COVID because of certain medical conditions, to get booster shots.

But boosters aren’t just for those who are most at risk—we strongly recommend that everyone stay up-to-date on all the vaccinations, including boosters. The more people that are vaccinated and boosted in our community, the more our whole community will be better protected, even those who can’t yet be vaccinated.

Who should get a booster shot?

Everyone aged 12 and older should get a first booster dose to be fully protected:

  • Four months after the second dose of Pfizer or Moderna
  • Two months after one dose of J&J

Second boosters have been authorized for people:

  • Ages 50 and over
  • Ages 12 and older who are moderately or severely immunocompromised
  • 18 and older who received J&J for their primary and first booster doses

If you are eligible, you can get the second booster at least four months after your first booster.

If COVID isn’t as bad for teens, why should they get a booster?

Most cases of COVID in teens aren’t severe, but on occasion, COVID-19 can cause serious illnesses that require hospitalization. Young people can also have health problems from the virus that last for months or longer, known as long-COVID. And even milder cases can mean they miss out on school, work, sports, vacations, and other activities. COVID isn’t going away–a booster is the best protection available and will help teens be able to do the activities they look forward to this spring and summer.

How do booster shots work?

How the vaccine works, including booster shots: An ingredient in the vaccine called mRNA teaches your cells how to recognize the protein on the outside of the coronavirus so that it can quickly identify it and mount a defense. When your cells detect that the coronavirus has entered the body, the immune system will make fighter cells and special proteins called antibodies to protect you against the virus. Once the mRNA has taught the cells, it quickly breaks down and it is cleared out of your body in a few days.

Watch this video on how vaccines work in your body.

Do I have to pay to get a booster shot? How do I get one?

COVID vaccines and boosters are free and you don’t need insurance or proof of citizenship. You can go to a vaccination site, a vaccination event, or get one from a clinic or pharmacy in many places in King County. Locations and help: or call 206-477-3977. Ask for your language if you need interpretation. If you have a disability and need accommodation, e-mail or call 206-477-3977.

How often will we have to keep getting boosters?

Viruses can change over time, and the changed versions are known as variants. As new variants develop, vaccines also need updates to continue to prevent severe illness.

For now, the current vaccine and booster is working very well against severe illness caused by the newer variants of COVID, but slightly less well than it was against past variants.  For this reason, a new booster may be recommended in the future.

It’s important for everyone who is eligible to get a booster now or as soon as you are eligible and not wait – you will still be able to get another booster if one is recommended in the fall or winter.

Meredith Li-VollmerContributor Meredith Li-Vollmer is a risk communications specialist at Public Health—Seattle & King County.

This article was originally posted in Public Health Insider on May 16, 2022 and re-posted in the June 2020 issue of AgeWise King County.