The Food and Drug Administration (FDA) authorized COVID-19 booster shots made by Moderna, Pfizer-BioNTech and Johnson and Johnson.

Who gets a booster, when they get it and which vaccine they get varies, so let’s discuss.

The FDA, coupled with recommendations from the Centers for Disease Control and Prevention (CDC), details eligibility of individuals for each vaccine booster as follows:

Moderna and Pfizer-BioNTech (single-dose booster given at least 6 months after primary series) :

• 65 years of age and older
• 18 through 64 years of age at high risk of severe COVID-19*
• 18 through 64 years of age with frequent institutional or occupational exposure to SARS-CoV-2*

*Underlying medical conditions as well as living or working in long-term care settings and other high-risk settings constitute as increased risk factors for acquiring and transmitting COVID-19.

Johnson and Johnson (single-dose booster given at least 2 months after single-dose primary regimen):

• 18 years of age and older

One may choose to stick with the same vaccine they got as their primary series/dose for their booster, but the choice to “mix and match” is also an option. Clinical data to support vaccine booster authorization was released and can be found on the FDA website.

In a study conducted by the National Institutes of Health (NIH), booster effectiveness, including the “mix and match” approach, was researched. The study found that those who were immunized with a Johnson and Johnson vaccine and later got a booster shot of either Pfizer or Moderna significantly benefitted more from a messenger RNA booster than a second dose of the Johnson and Johnson vaccine. Strong immune responses were also found in individuals who originally received Moderna or Pfizer and got boosters of either vaccine.

It is important to point out that this research study has yet to be peer-reviewed, the vast majority of the participants were white, the interval between primary doses and booster administration was less than six months and that a full-dose booster of the Moderna vaccine was given. The FDA authorized Moderna booster dose is half of the dose administered in the primary series.

“It’s really designed to say: Are there any concerning signals here? And based on the data, I think the answer is no,” Dr. John Beigel, co-author of the study and associate director for clinical research in the Division of Microbiology and Infectious Diseases at the NIH told NBC News.

For further context regarding the NIH study, take a look at this NPR article.

Booster shots provide additional protection to those who are vulnerable against COVID-19. However, the primary public health concern is to get the more than 65 million unvaccinated Americans, who have a significantly higher risk of infection, hospitalization and death and increase vulnerability in their communities in comparison to vaccinated individuals, vaccinated.

To decide if getting a booster shot (and from which vaccine) is best for you, please consult with your physician.

To find a COVID-19 vaccine near you, please visit vaccine.gov. COVID-19 vaccines are available to everyone at no cost, regardless of immigration or insurance status.