LOS ANGELES: The highly transmissible Omicron subvariant XBB.1.5 now accounts for 85% of all Covid-19 cases reported in the US this week, according to the latest estimates of the US Centres for Disease Control and Prevention (CDC).
The prevalence of XBB.1.5 kept increasing since late last year. It was up from 79.2% last week and 71.9% two weeks prior, reported Xinhua.
XBB.1.5 was growing in proportion in all regions nationwide, according to the CDC.
BQ.1.1 remains the second most prevalent strain at 9.4%.
The CDC first started tracking XBB.1.5 in November last year, when it accounted for less than 1% of cases nationwide. Since then, the strain is spreading quickly in the US.
Early study suggests XBB.1.5 has a couple of concerning mutations that suggest it is even more contagious than other strains, possibly the most transmissible one so far.
While XBB.1.5 is spreading easier, scientists said it does not seem to cause more severe disease.