Omicron Subvariant XBB.1.5 Becomes Dominant in U.S.

XBB.1.5, the Omicron subvariant that emerged in New York State, takes hold in the U.S., the Centers for Disease Control and Prevention (CDC) projection shows.

The new sublineage accounts for about 40.5% of confirmed U.S. COVID-19 cases, up from 20% a week ago, according to the projection released on Friday.

The XBB.1.5 is projected to be the dominant variant in the Northeast and increase in other regions of the country, said Dr. Barbara Mahon, director of the CDC's Coronavirus and Other Respiratory Viruses, in an interview with CBS News.

XBB.1.5 is a relative of the Omicron variant XBB, which is a fusion of 2 different B.A.2 variants, BJ.1 (BA. and BA.2.75, writes Eric Topol, MD, a professor in molecular medicine and executive vice-president of Scripps Research, a nonprofit medical research organization.

According to Topol, MD, the emergence of the XBB.1.5 variant in New York State was "coincident with the beginning of a steep rise of hospitalizations there."

The key mutation of XBB.1.5 is F486P, which was identified as one to be tied to immunity escape, Topol writes. And if XBB.1.5 has such a rapid growth advantage over BQ.1.1, that "isn't a good sign" because the immune evasion for XBB.1 is more than BQ.1.1

A recent study published in the journal Cell found that BQ.1, BQ.1.1, XBB, and XBB.1 are the "most resistant SARS-CoV-2 variants to date" and pose serious threats to existing COVID-19 vaccines, including the recently approved bivalent boosters against the Omicron subvariants BA.4/5. The study, however, was conducted in a lab outside the living organisms.

In October, the World Health Organization (WHO) reported data suggesting that XBB did not cause a more severe infection. However, the early evidence pointed to a higher reinfection risk than other Omicron subvariants.

The XBB subvariant now accounts for 3.6% of cases in the U.S.


Leave a comment

Your email address will not be published. Required fields are marked