STAT How concerned should we be about breakthrough coronavirus infections? "At the beginning of the pandemic, the CDC said that a close contact was somebody that you’re indoors with unmasked for 15 minutes or more. The equivalent of that with the Delta variant is not 15 minutes, it’s one second." Grimacing emoji. Recommended · Jul 25th, 2021, 11:43 amhealth covid-19 Paul Bausch