Another, faster-spreading omicron subvariant dominates new COVID cases in U.S.

Another form of the omicron subvariant BA. 2 has become the dominant version among new U.S. coronavirus cases, according to federal estimates released Tuesday, a development that experts had forecast over the past few weeks.

There was no indication yet that the new subvariant, known as BA. 2.12.1, causes more severe disease than earlier forms did. BA. 2.12.1 made up about 58% of all new U.S. cases, according to estimates by the Centers for Disease Control and Prevention for the week ending May 21.

As Americans approach their third Memorial Day weekend of the pandemic, the country is averaging more than 100,000 new confirmed cases per day for the first time since February, according to a New York Times database. Newly reported cases have been rising in nearly every state, many infections go uncounted in official statistics, so the true number of infections may be higher.

BA. 2.12.1 spreads more rapidly than previous versions of omicron including the form which sent U.S. cases soaring over the winter.