The explosive surge of coronavirus cases in the United States in recent months may indicate that a more contagious variant of the virus has emerged in the country, according to a document from the White House coronavirus task force obtained by NBC News. “This fall/winter surge has been at nearly twice the rate of rise of cases as the spring and summer surges,” the document reads. “This acceleration suggests there may be a USA variant that has evolved here, in addition to the U.K. variant that is already spreading in our communities and may be 50 percent more transmissible.” |