The evolution of the COVID virus is harder to monitor because testing levels have dropped off significantly from where they once were according to one researcher.

A new Omicron subvariant—XBB.1.5—is spreading rapidly throughout the northeastern US.

Less testing makes it harder to understand how the virus is changing says Dalhousie University infectious disease specialist, physician and researcher Dr. Lisa Barrett.

She says there is a bit of uncertainty surrounding how much virus is changing, how quickly, and where, because by and large, most jurisdictions have gone back to routine testing. “That does impair our ability… to know exactly where this virus is, and exactly how it’s moving so far.”