The B.1.1.7 variant of the coronavirus, which was initially discovered in the United Kingdom, is now dominating cases reported in areas across 26 states accounting for two-thirds of the United States’ population, Bloomberg reported on Friday.

According to the Centers for Disease Control and Prevention (CDC), the variant is said to be linked to “an increased risk of death compared to other variants.” Dr. Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases, said Friday during a briefing on the matter: “From the reports we’re seeing, [the variant] very likely could be a bit more serious but it definitely is more transmissible.”

The CDC groups the U.S. in 10 regions, and 5 of those regions’ cases were predominantly comprised of the UK variant, according to Dr. Rochelle Walensky, the agency’s director. She added that the variant made up anywhere from 4% to 35% of cases depending on the region, and made up 26% of cases across the country. The affected regions include areas surrounding New York City, D.C., Chicago, Atlanta, and Dallas, the CDC revealed in a statement.