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The third dose

5 things to know about COVID-19 vaccine boosters.

Article Author: Wesley Roberts

Article Date:

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As the United States grapples with another surge of COVID-19 infections, fueled by the highly contagious delta variant, the Food and Drug Administration (FDA) has given the green light for certain people to receive a third dose of the COVID-19 vaccine. Here are the top 5 things you need to know about these booster shots.

1. Who's eligible for a COVID-19 booster?
In mid-August, the FDA updated the Emergency Use Authorizations (EUA) for both mRNA COVID-19 vaccines, Pfizer and Moderna, to allow for the use of a third dose, or “booster,” for certain people with weakened immune systems. Following this, the CDC’s Advisory Committee on Immunization Practices cleared the booster shots for this particular population.

This group of immunocompromised individuals includes those who:

  • Are receiving active cancer treatment for tumors or cancers of the blood.
  • Received an organ transplant and are taking medicine to suppress the immune system.
  • Received a stem cell transplant within the last two years or are taking medicine to suppress the immune system.
  • Have moderate or severe primary immunodeficiency (such as DiGeorge syndrome or Wiskott-Aldrich syndrome).
  • Have advanced or untreated HIV infection.
  • Are receiving active treatment with high-dose corticosteroids or other drugs that may suppress your immune response. Corticosteroids are anti-inflammatory drugs that are typically used to treat rheumatologic disease, like rheumatoid arthritis, lupus, or vasculitis (inflammation of the blood vessels).

2. Why is a COVID-19 vaccine booster needed?
Individuals who are moderately to severely immunocompromised are at higher risk for serious, prolonged illness from COVID-19, and with the more dangerous variants circulating, it’s more important than ever to be protected.

Messenger RNA (mRNA) vaccines work by teaching your immune system to build antibodies that fight COVID-19.

“Studies show immunocompromised people don’t necessarily build the same level of protection after vaccination,” explained Shalika Katugaha, MD, system director of infectious diseases at Baptist Health. “Providing a third dose, or booster shot, gives the body another chance to build antibodies that will protect a person from getting sick if he or she is exposed to the virus.”

According to the CDC, immunocompromised people account for a large proportion of vaccinated individuals who are hospitalized with COVID-19, or “breakthrough cases.” This suggests that immunocompromised people are more likely to get sick or to spread the virus to others, even if they’re vaccinated.

3. Is the booster the same as the other doses?
“For now, yes, the third dose is the same as the first and second doses of the vaccine,” explained Dr. Katugaha. “Individuals should receive a booster from the same manufacturer [Pfizer or Moderna] as their initial doses.”

Booster vaccines for the Johnson & Johnson vaccine are not recommended at this time.

4. I’m eligible for a booster. When and where can I get one?
According to the CDC, you should wait 28 days between your second dose and your third dose of the COVID-19 vaccine. Also, you don’t have to go to the same location where you received your first two doses, just make sure it’s the same vaccine type. At this time, individuals will self-attest to being eligible for the booster.

5. When will the booster be available to the public?
If you don’t have a weakened immune system, you’re not eligible for a booster in the U.S. yet. That could change soon, though.

“The vaccines remain highly effective at preventing COVID-19 infection after the first two doses,” emphasized Dr. Katugaha. "Because of delta and other variants, U.S. health officials are actively evaluating the need for a third dose for all Americans, especially health care workers, the elderly and nursing home residents. Keep an eye out for more booster news soon.”

At Baptist Health, we want to help keep our community informed about COVID-19. For more information about COVID-19 vaccines, visit Click here to find a vaccination location near you.

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