The B.1.1.7 coronavirus variant from the United Kingdom that accounted for less than 1 percent of US infections at the beginning of the year, became the dominant strain responsible for more than an estimated 72 percent of infections in just over four months, a report published by the Centers for Disease Control (CDC) said on Thursday. “The B.1.1.7 VOC represented an estimated 0.2 percent of US infections during the 2-week period ending January 2 and increased to 66.0 percent during the 2-week period e ding April 24,” the report said.

During the latter period, the P.1 variant from Brazil accounted for about 5 percent of US infections, the source added. The April estimates were based on genetic testing of 25,000 samples from positive COVID-19 test specimens collected in 10 regions of the US.

However, a subsequent extrapolation of the April data using computer modeling yielded an estimate that the UK variant comprised 72.4 percent of US infections during the two week period ending May 8, the report added.