美国国家公共电台 NPR--The FDA considers the nation's next round of vaccines to battle COVID-19（在线收听）

The FDA considers the nation's next round of vaccines to battle COVID-19

Transcript

The Food and Drug Administration is meeting on Tuesday to make an extremely difficult but important decision: Should vaccines be updated to target the omicron variant?

A MARTINEZ, HOST:

The Food and Drug Administration meets today to plan the nation's next round of vaccines to battle COVID-19. NPR's Rob Stein reports.

ROB STEIN, BYLINE: The most powerful weapons the country has to coexist with the virus are the vaccines. They're what turns a potentially deadly disease into something more like a cold or the flu for many people. And the new technology the Moderna and Pfizer-BioNTech vaccines use gives scientists the power to update the shots quickly by simply reprogramming the genetic code in the vaccines to match whatever strain poses the biggest threat. And many independent experts think that's exactly what the FDA should do. Here's Deepta Bhattacharya. He's an immunobiologist at the University of Arizona.

DEEPTA BHATTACHARYA: Very clearly, I think what they should be doing is recommending that probably all vaccines include a component of omicron in there.

STEIN: To update the vaccines for another round of boosters in the fall to protect against what could be yet another dangerous surge this coming winter. But big questions remain. Would it make sense to go with a vaccine that only targets omicron or with a so-called bivalent vaccine that targets both the original strain of the virus and omicron? Moderna and Pfizer and BioNTech say they've developed new vaccines targeting omicron that should provide powerful, potentially longer-lasting protection. But others aren't so sure about switching up the vaccines. John Moore is an immunologist at Weill Cornell Medicine.

JOHN MOORE: Superficially, it sounds good, that this is what should be done because omicron variants are what is now dominating the U.S. and global pandemic. But the details cast significant doubt on whether switching to an omicron-based vaccine is justified.

STEIN: For starters, the new omicron vaccines appear to only stimulate the immune system to generate slightly higher levels of antibodies that can neutralize omicron. So it may make more sense to stick with the original vaccines since they still seem to be protecting most people from getting really sick or dying. Another big concern is the updated vaccines target the original strain of omicron. But new omicron sub-variants that are even better at dodging the immune system have already replaced it. Dr. Peter Hotez is a vaccine expert at the Baylor College of Medicine.

PETER HOTEZ: Omicron is already in the rearview mirror. And it's not clear that that's going to be useful anymore.

STEIN: So the FDA has raised the possibility of going even further, updating the COVID-19 vaccines more like the flu vaccines to anticipate where the virus may be heading. The country could, for example, go with new vaccines that target two new, even more contagious omicron sub-variants that have just now started taking over in the U.S. known as BA.4 and five. But that raises even more questions. Are we there yet with vaccines that use technology that's still so new to target a virus that's still so unpredictable? Who knows whether an entirely different strain could have taken over by next winter, rendering even that kind of vaccine less effective. Dr. Ofer Levy at Harvard is a member of an FDA advisory committee that will grapple with all of this today.

OFER LEVY: It's a delicate time. It's going to be a complicated deliberation. We don't have all the information we'd like. But we don't get to just sit around and speculate forever and wait for more and more information because the fall, winter are arriving. We have new variants that are spreading rapidly.

STEIN: And while the vaccines can be updated faster than older vaccine technology, it still can't happen overnight. The companies need time to test and then manufacture the millions of doses that would be needed to allow the country to live safely with the virus.

Rob Stein, NPR News.

(SOUNDBITE OF FLOBAMA'S "PIKASSO")