New omicron subvariant, most contagious yet, spreading rapidly in New York, as cases rise

The most contagious COVID-19 variant yet is rapidly spreading in the U.S., especially in the Northeast, where it is already responsible for 70% of new infections, according to the World Health Organization’s COVID-19 technical lead, Dr. Maria Van Kerkhove.

Its high rate of transmissibility of the new omicron subvariant XBB.1.5, is due to mutations that allow this virus to adhere to the cell and replicate easily, Van Kerkhove said during a WHO press conference yesterday.

“So far, we don’t have any data on severity yet or on the clinical picture,” Van Kerkhove said. “But we also do not have an indication that severity has changed with XBB.1.5,” she said.

WHO is monitoring the “very closely” through studies and in “real world data, when we look at hospitalization rates around the world among people who are infected with this subvariant,” Van Kerkhove said. WHO is doing a risk assessment on XBB.1.5 and expects to publish it in the next couple of days, she said.

“We are concerned about its growth advantage,” Van Kerkove said.

Health officials are particularly concerned about its spread in the Northeast, Van Kerkove said, “where XBB.1.5 has rapidly replaced other circulating variants.” Van Kerkove said increasing hospitalizations have been reported in the Northeast, where XXB.1.5 is now the dominant subvariant in circulation.

MORE COVERAGE: COVID-19 local hospitalization graphs

XBB.1.5 was first detected in New York the week before Thanksgiving, when it was responsible for 1.4% of laboratory-confirmed new cases in New York, according to data from the Centers for Disease Control and Prevention. Six weeks later, for the week ending Dec. 31, XBB.1.5 accounted for 72.2% of new infections in the state, CDC data show.

Case numbers in New York have been rising since Thanksgiving.

MORE COVERAGE: COVID-19 daily cases

Suffolk County continues to lead the state as the county, outside of the City of New York, with the highest number of new COVID-19 infections. The COVID-19 community level in Suffolk is classified by the CDC as high, with a case rate of 266.22 per 100,000 population.

The CDC recommends people in Suffolk wear mask indoors in public and on public transportation. People should stay up to date on vaccinations, get tested if they have symptoms and those at high risk for severe illness (people over age 60, people with pre-existing conditions and immune deficiency) should consider taking additional precautions, the CDC says.

The new subvariant has been detected in 29 countries so far, she said, noting that surveillance and sequencing has been declining worldwide so the new subvariant is likely present in more countries than that, Van Kerkove said.

“Vaccination remains absolutely critical to preventing severe disease and death no matter where you live,” Van Kerkove said. “If you are recommended to have a further dose, a booster dose, particularly if you are an older age — I’m talking to my friends and family who live in the northeast of the US and everywhere around the world — please get that next dose,” she said.