COVID-19 vaccine boosters can further enhance or restore protection that might have decreased over time after your primary series vaccination. To be up to date on your COVID-19 vaccination means that you’ve received all doses in your primary series and all boosters you are eligible for.
How do COVID-19 booster shots work?
A booster shot “boosts” your immune system’s response with an additional dose of vaccine. This extra dose helps your immune system remember how to fight a disease if you get exposed.
Boosters are given to people whose immune response has weakened over time since their last shot. A good example of this is a tetanus shot, which most people get boosters for over their lifetime.
COVID-19 booster shot eligibility
COVID-19 vaccine boosters provide the best protection against hospitalization and severe illness – including for vaccinated people who test positive for COVID-19.
All four COVID-19 vaccines are authorized to be given as booster doses by the U.S. Food and Drug Administration (FDA). Boosters are not new vaccines – they’re additional doses of an existing vaccine. For some people, especially children, a booster dose is smaller than the original vaccine dose.
The question of whether to get a booster shot depends on several things:
- Your age
- Which COVID-19 vaccine(s) you already received
- Whether you are considered immunocompromised
Certain medical conditions or taking medications to suppress the immune system can result in having a weakened immune system, also known as being immunocompromised.
If you have a weakened immune system, you’re especially vulnerable to COVID-19 and its risks. For example, this group of people is more likely to have a serious illness that lasts a long time.
Someone considered immunocompromised has:
- Been 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 CAR-T-cell or hematopoietic stem cell transplant within the last two years or are taking medicine to suppress the immune system
- Moderate or severe primary immunodeficiency (some examples include DiGeorge syndrome and Wiskott-Aldrich syndrome)
- Advanced or untreated HIV infection
- Active treatment with high-dose corticosteroids or other drugs that may suppress your immune system
Because booster shot guidelines depend on several factors, the Centers for Disease Control and Prevention (CDC) developed a tool to help you decide if or when to consider a booster shot for yourself or your child. Visit their website to check out this new tool.
Check out more information about the COVID-19 vaccine.