Variant from UK dominates in the U.S., CDC says

WASHINGTON — The coronavirus variant known as B.1.1.7, first identified in the United Kingdom last year, is now the most common lineage circulating in the United States, Centers for Disease Control and Prevention Director Rochelle Walensky said Wednesday.

The announcement came more as a milestone than a surprise: The CDC predicted in mid-january that the variant, which scientists estimate is roughly 50 percent more contagious than others, would become the dominant one in the United States by March, and cases have been rising exponentially. As of March 13, the B.1.1.7 variant accounted for about 27 percent of cases, according to the agency.

But the variant’s takeover is a sobering reminder of the persistence of the virus even amid a quickening vaccination campaign reaching about 3 million people in the United States each day.

Walensky said testing “remains an important strategy to rapidly identify and isolate infectious individuals — including those with variants of concern.” She also urged those eligible to get vaccinated.

“The virus still has a hold on us, infecting people and putting them in harm’s way. We need to remain vigilant,” Walensky said at a White House briefing. “We need to continue to accelerate our vaccination efforts and take the individual responsibility to get vaccinated when you can.”

Other variants of the coronavirus are also circulating and emerging, including “variants of concern” identified in South Africa, Brazil and California. In addition to being more transmissible, the variant first identified in Britain causes more-serious illness.

Walensky said Wednesday that hospitals are admitting more people in their 30s and 40s with severe disease while the number of older patients, who are more likely to be vaccinated, is dropping.