NEW YORK (AP) — Since the COVID-19 vaccines haven't been around that long, it's not yet known how long their protection lasts.
Experts are still studying vaccinated people to determine if and when boosters might be needed.
So far, evidence indicates shots by Pfizer and Moderna last at least six months, and likely longer. Another reason we might need follow-up shots is if the vaccines lose their effectiveness against variants.
Follow-up shots could contain vaccines for multiple variants. The need for them will also depend on the success of the global vaccination push, and tamping down transmission of the virus and emerging variants.