What Patients Should Know about Updated COVID-19 Vaccine Booster Shots


Dr. Amara Mulder, Internal Medicine, South Shore Medical Center

Amara Mulder, MD

A photo of several vials of COVID-19 vaccine

In recent weeks, "new" COVID-19 vaccine booster shots have been making headlines - and causing confusion for some people.

While most are familiar with the basics of COVID-19 vaccination at this point in the pandemic, it can be hard to keep up with all of the news regarding variants and vaccine guidelines.

Below, you can find clear answers to common questions about new vaccine booster doses, including what makes them different and who is eligible to receive a booster.

What are the updated boosters?

The new COVID-19 booster vaccine doses from Moderna and Pfizer-BioNTech are updated versions of the original vaccines.

These updated boosters are known as bivalent vaccines, as they target more than one strain of COVID-19 to provide maximum protection, similar to how the seasonal flu vaccine targets more than one strain of influenza each year.

The updated boosters were developed in response to new COVID-19 variants and were recently authorized by the FDA and recommended by the CDC.

Who should get the new updated booster?   

In order to be eligible, you must be 12 years old or older and must have completed your primary COVID-19 vaccination series or received your most recent booster dose at least two months ago.

If you meet that criteria, you're encouraged to receive the new booster as soon as possible.

If it has been less than two months since you were fully vaccinated or received a booster, you should wait until two months have passed.

The criteria above applies regardless of how many original booster doses you've already received, because the updated boosters contain virus strains that were not included in the original boosters.

In other words, even if you got a full primary series and one or more booster doses, you can still get the new updated booster vaccine as long as it has been at least two months since your last booster.

The updated Pfizer-BioNTech booster is approved for individuals age 12 and older; the updated Moderna booster is approved for individuals age 18 and older.

Children ages 5-11 are eligible for the original Pfizer-BioNTech booster, not the updated booster.

Why do I need an updated booster?   

Staying up to date on vaccines, including boosters, is the most effective way to prevent serious illness, hospitalization, and death from COVID-19.

While vaccine protection decreases over time, boosters re-stimulate the immune system and increase vaccine efficacy again.

Boosters are an important defense, even if you’ve already had COVID-19.

When and where can I get an updated booster?  

The updated booster shots are available at retail pharmacies and state-sponsored vaccine sites throughout Massachusetts.

To find the nearest available booster location, visit the state's VaxFinder website.

What if I recently had a COVID19 infection?

The CDC recommends that patients wait three months after testing positive for COVID-19 infection before receiving an updated booster.  

Is it safe to get the updated COVID-19 booster vaccine at the same time as the flu vaccine?


Where can I get more information?

For the latest information on COVID-19, including vaccines, please visit Mass.gov or the CDC website.

Amara Mulder, MD is Chief of Internal Medicine at South Shore Medical Center.