Roundup: New Omicron subvariants become health threat in U.S. summer COVID-19 surge

LOS ANGELES, July 11 (Xinhua) -- The latest and most contagious versions of Omicron subvariants, known as BA.5 and BA.4, have accounted for over 70 percent of new COVID-19 infections in the United States, leading to new surge in cases and hospitalizations nationwide.

BA.5 became the dominant variant in the United States, making up about 54 percent of new cases in the week ending July 2, according to data of the U.S. Centers for Disease Control and Prevention (CDC).