The Centers for Disease Control and Prevention (CDC) say the Delta variant (B1617.2) is as contagious as chickenpox in an internal document leaked to the Washington Post today.
The agency also said that, although unvaccinated people rarely get serious breakthrough infections, when they do get infected they can transmit the virus as easily as unvaccinated people.The document offers insight as to why CDC Director Rochelle Walensky, MD, MPH, earlier this week said vaccinated Americans should once again don masks when indoors in areas of high transmission—a category that 69.3% of US counties fall under, according to Reuters.