The mu COVID variant has not been detected in Pennsylvania. Here’s what we know about it

“Most of the work behind this concern is in lab studies of the virus,” said Andrew Noymer, an infectious disease expert [and associate public health professor] at the University of California, Irvine. “We know less about how much of a threat it is at the population level.” Noymer said he is still much more concerned about the delta variant’s ability to spread.