“Four weeks ago, the B.1.1.7 variant made up about 1 to 4% of the virus that we were seeing in communities across the country. Today it’s up to 30 to 40%,” Osterholm, who is the director of the Center for Infectious Disease Research and Policy at the University of Minnesota, told NBC’s “Meet the Press” on Sunday.

“What we’ve seen in Europe, when we hit that 50% mark, you see cases surge,” he said…

“We’ve been tracking it very closely since then,” she said. “Where it has hit in the UK and now elsewhere in Europe, it has really been catastrophic. It has driven up rates of hospitalizations and deaths and it’s very difficult to control.”

New research shows that in the US, the variant is 59% to 74% more transmissible than the original novel coronavirus. Gounder says cases in the US are “increasing exponentially.”