Why is the COVID vaccine age-based?

Infectious Disease Specialist and Epidemiologist, Céline Gounder, MD explains the dosing of the COVID-19 vaccine is based on the maturity of the immune systems, not size or weight.

So the vaccine doses are not based on your size, but really based on the age and the age of that child’s immune system. So how mature is the immune system and giving a vaccine dose that is targeted for that. The age at which you go through adolescence and sexual maturity is not the same pace at which your immune system develops. And so we’re really using age to measure how developed your immune system is and what dose of vaccine should be used.

This information is shared for educational purposes only and should not be used as a substitute for professional medical advice. The views expressed are those of the featured medical professional and reflect information available to that professional at time of filming. Always consult a health care provider for any personal health decisions. Click here for vaccine FAQs from the CDC.

Stay up to date with your COVID vaccine, including boosters!

COVID vaccines are safe and effective for everyone ages 6 months and older.

Immunity wanes over time. Keep up your protection against COVID by getting boosted when eligible.

Updated (bivalent) boosters are now available for adults and children 6 months and older. 

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THE CONVERSATION: Between Us, About Us.

Doctors, nurses, researchers and community health care workers provide facts and dispel misinformation about the COVID-19 vaccines in this FAQ video series from KFF with the Black Coalition Against COVID and UnidosUS.

A series for parents and caregivers created in partnership with the American Academy of Pediatrics provides the latest on the COVID-19 vaccine for kids.

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