New coronavirus subvariant BA.2.75.2 tops concerns as officials gear up for potential winter wave
As officials in California and beyond try to assess how severe a fall-and-winter coronavirus wave may be, one key factor is the growth of several new subvariants now emerging.
It’s too soon to say whether any of the newer variants will rise to prominence in the ways omicron and delta did. None have been documented in significant numbers in California or the nation. Still, experts say another super-spreading subvariant — combined with more people being indoors when the weather gets cold — could bring new challenges.
“As we get into this coming late fall and winter ... it is likely we will see another variant emerge,” Dr. Anthony Fauci, Biden’s chief medical advisor for the pandemic, said at a recent virtual talk of the Center for Strategic and International Studies.
There is wide expectation for an increase in COVID-19 cases this fall and winter. New York is already recording an uptick since hitting a seasonal low in early September.
For now, California remains in a lull, with cases and hospitalizations declining since mid-summer. But in Los Angeles County, weekly deaths remain elevated and well above springtime lows, likely fueled by a case rate that, while improved, is still substantial.
“We’re all prepared for some increase in cases this fall. I think we’d like that to be minimal, and we think if more people can go ahead and get protected with the new bivalent boosters, that will really help everyone try to dampen down the possibility of seeing a very big surge,” L.A. County Public Health Director Barbara Ferrer said.
But officials can’t rule out the possibility of a severe wave, given the unpredictability of the coronavirus.
“It would be foolish not to be prepared for uncertainty because we’ve just seen so much uncertainty,” Ferrer said. “This is a coronavirus. It mutates a lot. We cannot change that reality. (But) we feel very optimistic. We’ve got great tools.”
Following the distribution of COVID-19 vaccines, the pandemic’s previous surges have coincided with the emergence of new variants or subvariants that were more transmissible and circumvented the protections afforded by vaccines or previous infections.
Such constant mutations make the coronavirus a moving target. So while officials are largely confident that California and the U.S. are relatively well positioned heading into colder months — thanks to ready supplies of vaccines, therapeutics and the rollout of updated booster shots — they continue to keep a watchful eye on the horizon.
Most of the problematic variants have been referred to using letters from the Latin alphabet: epsilon, alpha, delta and omicron.
Omicron has dominated the globe since last fall, and today’s viral landscape is now marked by distinct subvariants of that strain. They are designated not with Latin letters but with alphanumeric identifiers that have gotten more complex over time.
Among them is BA.2.75.2, which Fauci identified as “one that looks suspicious — that it might start to evolve as a (troublesome) variant.”
BA.2.75.2 has not been found widely in the U.S., and the Centers for Disease Control and Prevention is not counting it separately from the less worrisome but similarly named BA.2.75.
“The one that we’ve been most concerned about recently is BA.2.75.2,” said Dr. Benjamin Pinsky, director of the Clinical Virology Laboratory at Stanford University.
At Stanford’s lab, scientists have identified only one case of that subvariant, he said.
The concern with BA.2.75.2 is that our collective antibodies — whether primed from past vaccination or a previous case — may be less able to recognize this new subvariant and ward off infection.
Specifically, a preprint study published in mid-September by scientists from Europe and Africa found that samples from random blood donors in Sweden were much less likely to recognize BA.2.75.2 compared to earlier subvariants.
The study also suggested the anti-COVID drug Evusheld was less effective against BA.2.75.2. Evusheld is a monoclonal antibody given to people with weakened immune systems to prevent coronavirus infection. Another monoclonal antibody, bebtelovimab, was still capable of detecting BA.2.75.2.
“Taken together, these data identify profound antibody escape by the emerging omicron sublineage BA.2.75.2, suggesting that it effectively evades current (antibody) immunity in the population,” the report said.
Dr. Eric Topol, director of the Scripps Research Translational Institute in La Jolla, said two of the more concerning subvariants are BA.2.75.2 and BQ.1.1.
“They have already been established as the most extreme immune escape seen to date,” he said. And being more adept than BA.5 — the current dominant omicron subvariant — “is not a good thing.”
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