The XBB1.5 mutant related to Omicron is currently the most frequently transmitted variant. It is one of the XBB strains, first detected in October, that is made up of a mixture of two other Omicron variants.
The rapidly spreading Omicron XBb1.5 mutant was estimated to have caused 43 percent of COVID-19 cases in the United States in the week ending January 14, data from the US Centers for Disease Control and Prevention showed on Friday.
The variant caused 30 percent of cases in the first week of January, higher than the 27.6 percent estimated by the centers last week.
The XBB1.5 variant related to Omicron is currently the most widely transmitted variant. It is one of the XBB strains, first detected in October, that is made up of a mixture of two other Omicron variants.
The World Health Organization said earlier this week that XBb1.5 may spur more spread of COVID-19, based on genetic traits and early growth rate estimates.
The increased prevalence of XBb1.5 cases has outpaced the previous dominant Omicron variant, BQ1.1 and BQ1, the PA5 offshoot, the Centers for Disease Control and Prevention said.
