COVID-19 vaccines help protect against severe illness, hospitalization and death. COVID-19 vaccines also help protect against infection. People who are vaccinated may still get COVID-19. When people who have been vaccinated get COVID-19, they are much less likely to experience severe symptoms than people who are unvaccinated.
To get the best protection against COVID-19, especially against severe illness and hospitalization, stay up to date on your COVID-19 vaccines.
When someone who is vaccinated with either a primary series or a primary series plus a booster dose gets infected with the virus that causes COVID-19, it is referred to as a “vaccine breakthrough infection.”
When people who are vaccinated get COVID-19 get a breakthrough infection, they are much less likely to experience severe symptoms than people who are unvaccinated.
People who get vaccine breakthrough infections can spread COVID-19 to other people. When a community reports more COVID-19 infections, that means more virus is circulating. When more virus is circulating, more breakthrough infections will occur even when vaccination rates are high. Even if you are vaccinated, if you live in a county with a high COVID-19 Community Level, you and others in your community, whether vaccinated or not, should take more steps to protect yourself and others, like wearing a mask in indoor public places.
CDC monitors reported vaccine breakthrough infections to better understand patterns of COVID-19 among people who are vaccinated and unvaccinated. The latest rates of COVID-19 cases and deaths by vaccination status are available on the CDC COVID Data Tracker.
To learn more, please visit https://www.cdc.gov/coronavirus/2019-ncov/vaccines/effectiveness/why-measure-effectiveness/breakthrough-cases.html