The Centers for Disease Control and Prevention on Friday revised down its estimates of how much of the XBB.1.5 omicron subvariant is circulating in the United States, even though it is still spreading at a faster rate than other versions of Covid-19.
XBB.1.5 accounted for 27.6% of sequenced Covid cases nationwide in the week ending January 7, in comparison with 18.3% on the weekend of December 31. The CDC previously reported that XBB.1.5 accounted for about 41% of the sequenced cases in the week ending December 31, more than any other variant.
Although the agency has revised its estimate downwards, XBB.1.5 stays the only omicron sub-variant currently showing significant growth in the United States. Second only to omicron BQ.1.1, which now accounts for 34% of sequenced Covid cases in the U.S.
XBB.1.5 accounts for more than 70% of the sequenced cases in the Northeastern United States, which frequently leads the remainder of the country.
People walk past a COVID-19 testing site in Recent York, United States, December 7, 2022.
Michael Nagle | Xinhua News Agency | Getty’s paintings
The World Health Organization has identified XBB.1.5 as the most infectious version of Covid. Researchers say XBB.1.5 has a mutation that makes it bind higher to human cells, which could make it higher at infecting people than other variants.
Dr. Ashish Jha, who heads the White House Covid Task Force, said in a series of Twitter posts on Wednesday that the XBB.1.5 subvariant is likely more immune to avoidance and may additionally be inherently more contagious since it binds more closely to human cells.
Jha said it’s unclear if XBB.1.5 is more dangerous than previous variants. But Dr. Robert Califf, who heads the Food and Drug Administration, noted in a series of Twitter posts on Wednesday that, for now, the variety of cases is increasing with no evidence of increased disease severity.
Jha warned that folks who last had a Covid vaccine before September, or who had an infection before July, are unlikely to have strong protection against XBB.1.5. Seniors who usually are not up-to-date on their injections are at increased risk of significant illness, Jha said.
U.S. health officials should soon have more data on how much protection the omicron boosters provide against XBB.1.5, Jha said. Califf said the boosters should offer some protection against the sub-variant based on research that checked out other sub-variants in the same family, XBB and XBB.1.
“It is highly likely that current bivalent vaccines provide some protection against XBB, especially in stopping serious illness and death,” Califf tweeted.
Nevertheless, scientists at Columbia University in a recent study noted that variants in the XBB family pose a serious threat to omicron amplifiers.
Weekly Covid cases have increased by about 16% to 470,699 over the past week, in response to CDC data. In keeping with the data, the average every day variety of hospital admissions has increased by 16% to over 6,500 in the last week. Weekly deaths also rose 8% over the previous week to over 2,700.