Are breakthrough infections being tracked?

Breakthrough COVID-19 cases are new infections in people who have already been fully vaccinated.

COVID-19 cases, hospitalizations, and deaths, as well as breakthrough infections, are tracked on a state-by-state basis. Many states monitor reports of breakthrough infections and report this information to CDC. However, this information is likely not complete because many breakthrough infections are mild or asymptomatic and therefore undiagnosed. States and CDC do investigate and track COVID hospitalizations and deaths in vaccinated people and this information is likely more accurate and a better measure of the risk of severe disease.

CDC data show that in August 2021, the risk of dying from COVID-19 in the U.S. was more than 11 times greater for unvaccinated people compared to fully vaccinated people, and the rate of hospitalizations associated with COVID-19 was 12 times higher among unvaccinated people.

Data continue to show that the COVID-19 vaccines are extremely effective in protecting individuals from catching and spreading the virus, but no vaccine provides 100% immunity. For the small percentage of vaccinated people who experience breakthrough cases, they are much more likely to be mild.

Updated October 20, 2021