美国国家公共电台 NPR--These two omicron subvariants could be the source of another COVID surge（在线收听）

These two omicron subvariants could be the source of another COVID surge

Transcript

Two subvariants that have emerged from the soup of Omicron offspring are among the most adept at evading immunity. They appear poised to become dominant in the U.S. and could fuel a new surge.

STEVE INSKEEP, HOST:

Pandemic still isn't over. Two omicron subvariants have new ways to get around our immune systems and are poised to become dominant in the United States, according to the Centers for Disease Control and Prevention. NPR health correspondent Rob Stein is covering the story. Rob, good morning.

ROB STEIN, BYLINE: Good morning, Steve.

INSKEEP: What is the news here of these subvariants?

STEIN: You know, Steve, scientists have been watching a swarm of even more transmissible subvariants that have been emerging as omicron has dominated the pandemic and evolved over the past year. And two of them have been gaining ground in the U.S. over the last few weeks called BQ.1 BQ.1.1. Here's Dr. Jeremy Luban at the University of Massachusetts.

JEREMY LUBAN: It's a little bit eerily familiar this time of year. Last year, we were similarly optimistic. We were coming out of the delta wave, and it was steadily decreasing. And we went into Thanksgiving to wake up to omicron. So there is this sort of deja vu feeling from last year.

STEIN: Because like the original omicron, these two new subvariants have found even more ways to sneak around our immune systems.

INSKEEP: I guess this is inevitable. It's evolution. People get sick and get some immunity, or they get vaccinated and get some immunity. And then the variations of the virus that get around that then are able to spread. So how much better are these variants?

STEIN: Yeah, absolutely. You know, new mutations in the virus's spike protein appear to make them maybe 2 to 7 times more immune-evasive than the BA.5 omicron subvariant that's been dominating the pandemic since the summer. I talked about this with Dr. Daniel Barouch, who's been studying the new viruses in his lab at Harvard.

DANIEL BAROUCH: The bad news is that it's likely that people who've been vaccinated and/or infected will still get infected. But fortunately, vaccine immunity and natural immunity will likely still be effective at preventing severe disease. And that's the most important thing. So it's a cause for concern but not a cause for alarm.

STEIN: Because even though these new subverts could infect more people, they don't appear to make people sicker than the previous variants.

INSKEEP: But could they lead to a winter surge?

STEIN: Well, you know, they certainly won't help. I talked about this with Samuel Scarpino from The Rockefeller Foundation.

SAMUEL SCARPINO: Both of these variants are associated with an increase in cases in the U.S. So the question is whether this increase is going to be nationwide and whether the size of the increase and the surge will be something like what we experienced with delta and omicron or much smaller.

STEIN: And possibly much shorter. I asked White House adviser Dr. Anthony Fauci about this. He doubts any new surge will get anywhere near as bad as last winter's.

ANTHONY FAUCI: We are hoping that the amount of immunity that has been induced either by prior infection or by vaccination - and hopefully, more people will go and get their updated vaccine, the bivalent vaccine - that that would mitigate a real surge and at worst will get a blip versus a major surge.

STEIN: You know, while some preliminary studies have questioned whether the new boosters are any better than the original vaccine at protecting against omicron, Fauci says the jury's still out about that. And in fact, Pfizer and BioNTech released a statement today saying a study involving 900 volunteers shows their new booster stimulates much higher levels of antibodies that could neutralize the Ba.5 omicron subvariant than the original vaccine. But another worry is these new subvariants are likely to render the last monoclonal antibody drugs useless. And even just a blip of a COVID resurgence could strain hospitals also struggling with the flu and RSV.

INSKEEP: Rob, thanks so much.

STEIN: You bet, Steve.

INSKEEP: NPR health correspondent Rob Stein.