Dr. Rochelle Walensky, director of the US Centers for Disease Control and Prevention, said she's worried the United States could see "another avoidable surge" of Covid-19 if mitigation measures – such as mask-wearing, physical distancing and avoiding crowds or travel – are not followed.
"As I've stated before, the continued relaxation of prevention measures while cases are still high and while concerning variants are spreading rapidly throughout the United States is a serious threat to the progress we have made as a nation," Walensky said during a White House Covid-19 briefing on Monday.
"Increasingly, states are seeing a growing proportion of their Covid-19 cases attributed variants," Walensky said, adding that for instance, two newly identified variants – B.1427 and B.1429 – are estimated to account for 52% of cases in California, 41% in Nevada and 25% in Arizona.
The B.1.1.7 variant, first identified in the United Kingdom, is estimated to be responsible for 9% of cases in New Jersey and 8% in Florida, Walensky said.
"We are at a critical point in this pandemic, a fork in the road, where we as a country must decide which path we are going to take," Walensky said. "We must act now, and I am worried that if we don't take the right actions now, we will have another avoidable surge – just as we are seeing in Europe right now and just as we are so aggressively scaling up vaccination."