COVID Vaccine Boosters: What You Need to Know
Nov 22, 2021


Note: This post has been updated to reflect the latest CDC recommendations, as of November 19, 2021. 

There’s been a lot of confusion lately over COVID vaccine boosters and third doses. What is the difference? Who needs them? When should they get them? And why are they necessary? As the pandemic continues and more research comes out, public health recommendations are evolving to ensure they’re based on the most up-to-date science. Here’s the latest on COVID vaccine boosters.

Who needs two doses?

Anyone 5 years old and over who hasn’t already been vaccinated against COVID-19 should get two doses of a COVID vaccine. Note: Pfizer’s COVID vaccine is the only one currently available for kids ages 5-17 years old in the United States.

Anyone 18+ years old who originally got the single dose of Johnson & Johnson (also known as J&J or Janssen) vaccine should get a booster dose*, at least 2 months after the first dose.

Who needs three doses? 

Anyone 12+ who has a moderately or severely weakened immune system who also got the Pfizer or Moderna vaccine should get a third full dose of the same vaccine, 28+ days later. This additional dose of mRNA COVID-19 vaccine should improve immunocompromised people’s response to their initial 2-dose vaccine series.

All adults who originally got the Pfizer or Moderna vaccine at least 6 months ago are now eligible to get a booster dose* of COVID-19 vaccine. Boosters are especially important for:

  • All adults age 50 and over
  • Anyone 18 years and older living in a long-term care facility

If you don’t fit it into any of the above groups, the CDC says you don’t need another dose yet. This could change in the future as we get more data, but for now, two doses still greatly lower the chances you’ll get seriously sick with COVID.


Have you read:

Do people need to get the same vaccine they originally received when they get the booster?

That depends. Those who need a third dose because of a weakened immune system should get the same vaccine for the additional dose.

For people who don’t have a weakened immune system, but who should get a booster, the CDC says that you can use any COVID-19 vaccine as a booster dose. It doesn’t need to be the same vaccine that you originally received. If you aren’t sure which vaccine would be best for you, talking to a healthcare provider can help you decide.

Why are boosters necessary?

Getting another dose could help bump up your protection against COVID-19, especially if you’re in a group that’s most at risk of getting seriously sick from the disease, protection has gone down over time, or you didn’t get strong enough protection from the original dose(s).

How safe are the booster doses?

Studies so far point to the booster dose of COVID-19 vaccines being just as safe as previous doses. While health officials will continue to keep a close eye on the safety of COVID-19 vaccines (including boosters), side effects don’t appear to be any more common or serious compared to previous doses.

If I don’t get a booster, am I still considered “fully vaccinated”? 

Yes. You’re still considered fully vaccinated if you got the first two doses of either Pfizer’s or Moderna’s COVID vaccine OR the single-dose COVID vaccine by Johnson & Johnson.

Does a booster mean the vaccine doesn’t work? 

Nope. It’s true that you can still get COVID-19 after being vaccinated, but all three vaccines work really well at lowering your chances of dying or landing in the hospital due to COVID-19. The extra dose simply helps dial up the protection even more for folks who maybe didn’t respond fully to the original series or whose protection is going down over time.

As researchers get more data and the virus changes over time, the number and schedule of doses for COVID-19 vaccines might need to be tweaked to give people the best protection possible against dying or being hospitalized from COVID-19. This doesn’t mean the recommendation was wrong before. It means that recommendations are based on the best available data, and that data can change over time.

Recommendations seem to be changing all the time. How can I keep up?

We get it. As we get more information about the virus and vaccinate more people, we’re having to adapt. Recommendations are based on the best science available at the time. As things change, we’ll have to too. For the latest science-based info, we recommend visiting Vaccinate Your Family.

* NOTE: Booster doses of the Pfizer or Johnson & Johnson COVID-19 vaccines are the same dosage as the original series. Moderna’s COVID-19 vaccine booster is a half dose.


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5 responses to “COVID Vaccine Boosters: What You Need to Know”

  1. Elizabeth Engelhardt says:

    I have a question. Should I still go get my booster shot even if my husband is at home with Covid or should I wait?

  2. Georgia says:

    I really found this blog post useful and completely agree with you in so many ways. The more I research vaccines the more I realise just how important getting the jab is. I had my first dose last Monday and I feel 1 step closer to living a normal life or the “new” normal. Whether it is the new normal or the old normal it is one step closer regardless of the circumstances. I read an article by (Orenstein & Ahmed, 2017) that explains the importance of getting vaccinated not only for personal protection, however, also for the community and cities that live around us. I related this article to your blog post when I read what you stated about ” feel like I am in a cocoon that is warm and safe watching the world go by.” This really sums up how lockdowns and isolation can feel like during COVID-19. This is why getting vaccinated is not only important for ourselves and overall health & protection but it is also important that we do for the people around us so we can see our loved ones again from all around the world and close. Thank you for writing about this really important topic, I thoroughly enjoyed it.

  3. May please schedule a (Covid ) booster shot for my 88 year old husband and myself…I am 81, as as soon as possible at store #6614 . We live on Main Street in Bothell. 98011

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