The U.K. variant of COVID-19 is now making up the majority of new coronavirus cases in the United States, CDC Director Rochelle Walensky said Wednesday. “Based on our most recent estimates from CDC surveillance, the B.1.1.7 variant is now the most common lineage circulating in the United States,” she said. There are 16,275 confirmed cases of the strain, according to the CDC. The U.S. has seen a surge in cases in the last few weeks, partly because of the U.K. variant, Walensky said. Some research suggests that the strain is said to be more contagious, and possibly more deadly than other coronavirus mutations. Last month, experts anticipated that the variant would become dominant if it had not already taken over. At the time, the CDC did not release any information regarding the prevalence of the strain, but did agree that it was only a matter of time before it made up the majority of cases.