U.S. tries out new coronavirus testing strategy in Greenville, N.C.

Greg Martin, director of the Emory/Georgia Tech Predictive Health Institute, said this is possible because rapid tests are becoming more accurate, and PCR (polymerase chain reaction) lab tests, faster, “blurring the line” between the two. A single rapid test using a nasal swab or saliva, which takes as little as 10 to 15 minutes, can still produce roughly 15 percent false negative results and 1 to 2 percent false positives, studies show — but that accuracy improves dramatically when testing multiple times in a short period.