The BA.4 and BA.5 subvariants of Omicron are estimated to make up nearly 13 percent of all new U.S. COVID-19 cases in the latest week, the U.S. Centers for Disease Control and Prevention (CDC) said on Tuesday.
BA.4 made up 5.4 percent of the new cases for the week ending June 4, while BA.5 made up 7.6 percent during the same time, according to CDC estimates.
Another subvariant BA.2.12.1, which is the dominant variant in the country, made up 62.2 percent of all new U.S. cases in the same week.
The two new sublineages, BA.4 and BA.5, were added to the World Health Organization's monitoring list in March, and designated as "variants of concern" by the European Centre for Disease Prevention and Control.
CDC data showed the two sublineages were present in all U.S. regions.