XBB.1.5 subvariant has grown to nearly half of all COVID- cases: CDC

The fast-spreading Omicron XBB.1.5 subvariant is estimated to make up nearly half of U.S. COVID-19 cases, putting it on track to become the dominant subvariant in the country, according to Centers for Disease Control data, Reuters reports. XBB.1.5 is estimated to account for 49.1% of COVID cases in the country for the week ended Jan. 21, a jump from 37.2% the previous week.