The true prevalence of breakthrough COVID-19 cases is difficult to track due to a lack of comprehensive testing and surveillance, but a new analysis from The Wall Street Journal suggests infections among fully vaccinated people are still very rare — even with the highly transmissible delta variant circulating in the U.S.
The Journal analyzed data on breakthrough cases occurring between Jan. 1 and early August provided by health departments in 44 states and Washington, D.C. The six states that did not share data said that information was unavailable or that they only track breakthrough infections that result in hospitalizations or death.
Four things to know:
1. In total, 193,204 breakthrough cases were reported, representing 0.1 percent of the more than 136 million people fully vaccinated in these states and the U.S. capital.
2. Public health experts said the actual tally is probably higher, since some people with breakthrough cases may be asymptomatic.
3. At least 11 states saw more than half of their reported breakthrough cases occur between July 1 and early August, when the delta variant quickly gained dominance in the U.S. This trend suggests the variant may be causing more breakthrough infections than earlier strains, the Journal said.
4. Overall, health departments said breakthrough cases were rare and resulted in very few hospitalizations or deaths.
To view the full report, click here.