The omicron subvariant BA.2 accounts for more than one-third of COVID-19 cases nationwide and more than half of cases in the Northeast, according to the latest variant proportion estimates from the CDC.
Four notes:
1. The subvariant accounted for an estimated 34.9 percent of COVID-19 cases in the week ending March 19. This figure sat at 22.3 percent in the week ending March 12 and 12.6 percent in the week ending March 5.
2. Of HHS' 10 surveillance regions, the subvariant was most prevalent in region 1 and 2 at 55.4 percent and 51.8 percent, respectively. Region 1 includes Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont, while region 2 includes New Jersey, New York, Puerto Rico and the Virgin Islands.
3. Rhode Island had the highest proportion of BA.2 cases of all states at 24.1 percent, based on specimens collected in the month ending Feb. 26. West Virginia had the lowest proportion of cases at 0.1 percent.
4. The new estimates come as the U.K. grapples with an uptick in both COVID-19 cases and hospitalizations due to the variant. Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, said he would not be surprised to see an uptick in infections in the U.S., though a major surge is unlikely.
"The extent of it and the degree to which it impacts seriousness of disease like hospitalizations and death remains to be seen," he told The Washington Post March 22. "I don't really see, unless something changes dramatically, that there would be a major surge."