The Centers for Disease Control and Prevention revealed Friday it is now tracking a new COVID-19 variant of concern around the U.S. known as XBB, which has grown to make up an estimated 3.1% of new infections nationwide. The strain’s prevalence has grown furthest so far in the Northeast, according to the agency’s weekly estimates.
More than 5% of infections in the regions spanning New Jersey through Maine are linked to XBB, in this week’s “Nowcast” from the CDC. XBB is behind a vast swath of infections across some South Asian countries and has made up an increasing share of reported virus sequences from around the world and in arriving international travelers. Earlier this month, the CDC offered preliminary estimates suggesting XBB is potentially doubling in proportion about every 12 days.
That could be faster than the current pace of the BQ.1 and BQ.1.1 variants now dominant across the country. However, the Biden administration’s top COVID officials and experts say they do not think XBB will pose a new threat on the scale of when the Omicron variant first emerged a year ago. “Where we’ve seen surges, they’ve seen mostly it be driven by seasonality, people coming inside, spending more time around one another, but not being specifically being driven by the emergence of a new variant,” the CDC’s Ian Williams told a meeting of the CDC’s emergency response and preparedness advisers earlier this month.