Omicron subvariant XBB jumps to 18% of U.S. COVID cases – CDC

Dec 23 (Reuters) –

The highly-contagious Omicron subvariant XBB has surged to
more than 50% of COVID-19 cases in the northeastern United
States and risks spreading fast as millions of Americans begin
holiday travel on Friday.

In the week ended Dec. 24, XBB was estimated to account for
18.3% of the COVID-19 cases in the United States, up from 11.2%
in the previous week, according to the U.S. Centers for Disease
Control and Prevention on Friday (CDC).

The subvariant is currently dominant in the Northeast,
but accounts for fewer than 10% of infections in many other
parts of the country, the CDC said.

Andrew Pekosz, a virologist at the Johns Hopkins Bloomberg
School of Public Health in Baltimore, said holiday travel in the
United States could speed up the XBB subvariant’s spread across
the country.

The American Automobile Association (AAA) had estimated
that 112.7 million people planned to travel 50 miles (80 km) or
more from home between Friday and Jan. 2, up 3.6 million
travelers over last year and closing in on pre-pandemic numbers.

But that number was likely to be diminished by the

treacherous weather

complicating air and road travel going into the weekend.

“Anytime a new variant moves to a different geographic
area, it does run the risk of sort of spawning a mini-outbreak
in that area,” Pekosz said.

Still, Pekosz said he does not see the XBB subvariant
driving the kind of massive surges seen last winter from the
original Omicron variant.

Top U.S. infectious diseases expert Anthony Fauci said in
November that updated COVID-19 booster shots – which target the
original variant of the coronavirus as well as BA.4 and BA.5
subvariants – would still provide “some protection, but not the
optimal protection” against the XBB variant.

XBB is a subvariant of the BA.2 variant.

The earliest BA.5 lineage now represents just a small
fraction of cases, having been overtaken by its offshoots, BQ.1
and BQ.1.1, which still remain the dominant variants in the
United States, though on the decline.

The rise in cases of the new variant comes a week after the
White House COVID response coordinator urged Americans to get
their flu vaccines and updated COVID-19 boosters, pointing to
rising cases in about 90% of the country ahead of the year-end
holidays.

The XBB variant has been driving up cases in parts of Asia,
including Singapore. While some experts have said it is more
transmissible, it has not resulted in a surge in
hospitalizations.

BQ.1.1 and BQ.1 are expected to account for 63.1% of cases
in the United States, compared with 64.6% a week ago, the CDC
said.
(Reporting by Khushi Mandowara in Bengaluru and Michael Erman
in New Jersey; Editing by Shounak Dasgupta, Shinjini Ganguli
and Deepa Babington)