The Centers for Disease Control and Prevention revealed on Friday that it is now tracking a new COVID-19 variant of concern around the US, known as XBB, which caused an estimated 3.1% of new infections nationwide Is.
According to the agency’s weekly estimates, the spread of tension in the Northeast has become the highest ever. In this week’s “Nowcast” from the CDC, more than 5% of infections in areas stretching from New Jersey through Maine are linked to XBB.
XBB is behind a significant number of infections in some South Asian countries and has led to an increase in virus sequences reported from around the world and reaching international travelers.
Earlier this month, the CDC offered preliminary estimates that suggested XBB was potentially doubling at a rate of every 12 days. This could be faster than the current speed of the BQ.1 and BQ.1.1 variants that are now in effect across the country.
However, top COVID officials and experts in the Biden administration say theyThe XBB would pose a new threat on the scale of when the Omicron variant first appeared a year earlier.
The CDC’s Ian Williams said, “Where we’ve seen an increase, they’ve seen it be mostly because of weather, people coming inside, spending more time around each other, but also particularly from the emergence of a new variant.” Not inspired.” A meeting of CDC’s emergency response and preparedness advisors earlier this month.
XBB is one of several new lineages that have displaced BA.4 and BA.5, the Omicron variant siblings that caused a wave of cases over the summer. As of this week, the CDC says BA.5 has dwindled to less than 1 in 5 new infections nationwide and BA.4 has now virtually disappeared.
The arrival of the stress comes at a time when most regions, including the Northeast, are seeing relatively flat or slowing COVID-19 hospitalization rates.
About 3 in 4 Americans currently live in counties considered at a “low” COVID-19 community level, the lowest level of precautions recommended by the agency, according to data released by the agency on Friday.
“However, there is a lot of concern that a new variant could emerge and start us all over again. So there’s a lot of work to be done to make sure we’re ready and thinking about it and seeing if it emerges around the world, so we can be prepared,” Williams said.
a “recombinant” strain
First named by scientists in September, XBB is thought to be a “recombinant” of two different Omicron subvariants — BA.2.10.1 and BA.2.75 — that emerged earlier this year. It is the latest in a rash of strains carrying mutations that can evade the leading COVID antibody drugs.
“There has been a rapid increase in XBB, but it does not appear to be particularly more severe than other variants,” said Derek Smith, director of the Center for Pathogen Evolution at the University of Cambridge. month.
Smith helps lead the National Institutes of Health’s effort to quickly detect and analyze emerging variants as part of an “Avengers-like” program that reaches out to multiple US federal agencies and outside experts. is spread.
“XBB, this caught our attention and was then prioritized, even though it was a small number, because it had a significant number of substitutions from viruses that are currently circulating. [receptor-binding domain]Which meant it could be an escape variant,” Smith said.
Scientists on the NIH effort quickly began ordering supplies to build mock-ups of XBB to test how well it might evade immunity in the lab compared to other strains.
The data now also suggests that the new COVID boosters will provide at least some better protection against the strain.
A study released earlier this month by Pfizer and BioNTech, which was posted as a preprint and has yet to be reviewed, found that their updated COVID booster was able to trigger better antibody responses against the XBB strain. Seems effective.
However, the company’s scientists also said that it was one of the variants that saw the worst neutralization from its shot.
“It doesn’t go off the map, but it goes down. So, you can expect some protection, but not optimal protection,” Dr. Anthony Fauci, chief medical adviser to the president, said at a White House briefing on Wednesday. “