No, all COVID-19 vaccines have been effective at reducing the risk of severe illness, hospitalization, or death. Getting a series of vaccine doses over an extended period of time – like months or years – is common for many vaccines. Over time. updated vaccine doses are needed to protect against new variants of a virus. The researchers who developed the COVID-19 vaccines continue to monitor how well the vaccines protect against new strains of the virus and this research has led to updated vaccines.

Updated October 29, 2024