Why do I need a booster, since the COVID-19 vaccines are effective?

The protection offered by the FDA-approved and authorized vaccines is very powerful, but it starts to weaken after two months for the Johnson & Johnson vaccine, and after five months for the Pfizer and Moderna vaccines. Getting a booster shot extends the protection, even against the delta and omicron variants.

The CDC recommends that people who are vaccinated get a booster dose when they are eligible, and that they stay up to date with COVID-19 vaccinations.