Who’s Eligible for a COVID-19 Booster?

Generally speaking, the CDC recommends that everyone ages 12 and over can receive a COVID-19 booster shot. However, which type of shot you’re eligible for depends both on your age and which vaccine you received for your initial vaccine series.

The chart below helps to break down COVID-19 booster shot eligibility.

*On May 5, 2022, the FDA limited the Emergency Use Authorization (EUA) granted to the vaccine. The Johnson & Johnson vaccine is now only authorized for use in people ages 18 years and older who can’t receive other approved COVID-19 vaccines or who would choose not to get vaccinated otherwise. Individuals who cannot receive other COVID-19 vaccines include those for whom it is not clinically appropriate or who don’t have access to the Moderna or Pfizer vaccine.

Overall, mRNA vaccines are typically preferred over the Johnson & Johnson (J&J) vaccine, both for the initial vaccine series and for boosters.

The recommendation above comes after an updated risk-benefit analysis from the CDC determined that, compared with the J&J vaccine, the two mRNA vaccines have a higher effectiveness and a better safety profile.

According to the CDC, there are some instances in which the J&J vaccine may still be considered for use. These are if you:

• had a severe allergic reaction, called anaphylaxis, to a previous dose of the Pfizer or Moderna vaccine
• have a known allergy to one of the ingredients in the Pfizer or Moderna vaccine
• don’t have access to either mRNA vaccine and would otherwise remain unvaccinated
• choose to receive the J&J vaccine anyway, despite the potential risk of very rare, but serious, side effects

Per the CDC, immunocompromised people ages 12 and older are also eligible for a COVID-19 vaccine booster. Some examples of people who are immunocompromised include people who:

• are taking drugs that suppress the immune system
• are getting treatment for cancer
• have previously received an organ or stem cell transplant
• have advanced or untreated HIV
• have an inherited immunodeficiency syndrome

Compared with uncompromised immune systems, immunocompromised people may have a weaker immune response to the COVID-19 vaccine. Because of this, they receive an additional vaccine dose as a part of their initial vaccine series.

The table below helps to explain booster eligibility for immunocompromised individuals.

*On May 5, 2022, the FDA limited the Emergency Use Authorization (EUA) granted to the vaccine. The Johnson & Johnson vaccine is now only authorized for use in people ages 18 years and older who can’t receive other approved COVID-19 vaccines or who would choose not to get vaccinated otherwise. Individuals who cannot receive other COVID-19 vaccines include those for whom it is not clinically appropriate or who don’t have access to the Moderna or Pfizer vaccine.

Similar to people with typical immune responses, mRNA vaccines are usually preferred over the J&J vaccine.

There are many ways to schedule a booster shot. In some cases, you can simply return to the same location that you got your initial vaccine series from.

Other ways to schedule a booster include:

• asking your doctor or pharmacist if they provide COVID-19 boosters
• using the search tool on vaccines.gov to find a booster shot close to you
• contacting your state health department through the CDC or your local health department through the National Association of County and City Health Officials to learn where boosters are available in your area

When you do get your booster appointment on the calendar, don’t forget to bring your CDC vaccine card along with you. The vaccine provider will need to update it with information about your booster shot.

It’s typical to have some side effects after getting your COVID-19 booster. But some people may not experience any side effects at all.

Generally speaking, the CDC finds that common side effects of the booster shot are similar to those from your initial vaccine series. They may include:

• redness or discoloration, swelling, or pain at the injection site
• fatigue
• fever, with or without chills
• muscle pain
• headache
• nausea

These side effects are usually signs that your immune system is responding to the booster. They’re typically mild and go away on their own in a few days.

In the meantime, you can treat side effects through the use of over-the-counter medications that can ease symptoms like discomfort and fever. These include acetaminophen (Tylenol), ibuprofen (Advil, Motrin), and naproxen (Aleve).

Serious side effects from COVID-19 vaccines are typically very rare. Some examples of such side effects and how frequently they occur, according to the CDC, are:

• Anaphylaxis (any vaccine): 5 people out of 1 million
• Myocarditis (mRNA vaccines): 1,390 verified reports out of millions of doses
• Thrombosis with thrombocytopenia syndrome (J&J): 60 confirmed reports out of 18.5 million doses
• Guillain-Barré syndrome (J&J vaccine): 310 preliminary reports out of 18.5 million doses

A booster shot is given to people who have completed their initial vaccine series. It’s used to bolster an immune response that faded over time.

The Pfizer booster is the same dose as those given for the initial vaccine series. Meanwhile, the Moderna booster only contains half the dose that people receive as a part of their initial vaccine series.

A third dose is given to immunocompromised individuals who received one of the two mRNA vaccines as their initial vaccine series. An additional (second) dose of an mRNA vaccine is given to people who got the J&J vaccine initially.

Additional doses are given to this group because their response to vaccination may be lower than in healthy individuals. Immunocompromised people can also get a booster shot when eligible.

We’re still learning more about how long protection from a booster lasts. Generally speaking, it appears to increase protection for a period of time before beginning to wane. Let’s see what some of the current research says.

One 2022 study looked into vaccine effectiveness against the Omicron variant. It observed the following in people who received the Pfizer vaccine as their initial series:

• A Pfizer booster increased vaccine effectiveness to 67.2 percent for 2 to 4 weeks after the booster, before declining to 45.7 percent after 10 or more weeks.
• A Moderna booster increased vaccine effectiveness to 73.9 percent for 2 to 4 weeks after the booster, before declining to 64.4 percent at 5 to 9 weeks.

Another 2022 study assessed the effectiveness of the Moderna vaccine against the Omicron variant. It found that the effectiveness of the Moderna booster was 71.6 percent for 14 to 60 days after a booster, declining to 47.4 percent after 60 days.

A final 2022 study by a group at the CDC also found that the effectiveness of the mRNA boosters against emergency department visits or hospitalization declines over time:

• The mRNA booster effectiveness at preventing emergency department visits was 87 percent in the 2 months after a booster and 66 percent by month 4.
• The mRNA booster effectiveness at preventing hospitalization was 91 percent in the 2 months after a booster and 78 percent by month 4.

Since protection from COVID-19 boosters typically wanes with time, you may be wondering if you’ll need another booster shot in the future. While this seems likely, the answer to this question is still unclear.

Pfizer recently requested that the Food and Drug Administration (FDA) grant an emergency use authorization for an additional booster for individuals ages 65 and older.

Meanwhile, Moderna requested authorization for an additional booster for people ages 18 and older.

In addition to naturally waning immunity, the emergence of COVID-19 variants also impacts protection. These newer variants, such as the Omicron variant, are better able to evade protection that can come from our current vaccines and boosters.

As such, both Pfizer and Moderna are evaluating the effectiveness of an Omicron-specific booster for use in adults.

The CDC recommends that all people ages 12 and older receive a COVID-19 booster to help strengthen protection against COVID-19. Getting an mRNA vaccine as your booster is usually preferred over receiving the J&J vaccine.

Receiving your booster can be important for staying up-to-date on your COVID-19 vaccines. If you haven’t received your booster yet, there are many resources available to help you do so. If you have questions or concerns about the booster, reach out to your doctor or another healthcare professional.

Similar to your initial vaccine series, the protection from the booster decreases over time. To cope with waning protection and the spread of a new Omicron variant, the FDA recently authorized a second COVID-19 booster shot for people over 50 and for certain immunocompromised people.