The U.S. Centers for Disease Control and Prevention (CDC) said on Friday that COVID subvariant JN.1 accounts for 39% to 50% of cases in the United States as of Dec. 23, according to the agency’s projections.

This is an increase from the estimated 15% to 29% of cases in the United States, the CDC had projected as of Dec. 8.

The CDC said the variant continues to cause an increasing share of infections and is now the most widely circulating variant in the country.