On page 17 of an internal CDC document published in a July 30, 2021, article in the Washington Post, the CDC notes that “Delta variant breakthrough cases may be as transmissible as unvaccinated cases” [230]. The term “breakthrough cases” refers to people who get COVID-19 despite being fully vaccinated. The CDC makes that point again on page 22 of the document, and also notes that vaccines “may be less effective at preventing infection or transmission. . . . Therefore, more breakthrough and more community spread despite vaccination.”
