AUDIE CORNISH, HOST:
With unwelcome news for any time of the year, let alone a time when many are traveling, scientists have detected a new coronavirus variant in South Africa that is causing alarm. The World Health Organization has just designated it an official variant of concern and given it the name Omicron. The U.S. will now restrict travel from South Africa and neighboring countries starting Monday. Here to tell us what is currently known about this variant is NPR Global Health Correspondent Michaeleen Doucleff. Welcome back.
MICHAELEEN DOUCLEFF, BYLINE: Thank you for having me.
CORNISH: It's not unusual for us to see variants in this pandemic, right? Just a few weeks ago, you were on the show talking about another variant that didn't turn out to be a wide-scale problem. Why are health officials concerned about this one?
DOUCLEFF: Yeah. So first off, I want to be clear that very little is known about this variant. Scientists in South Africa just identified it on Tuesday from someone who had got sick a couple of weeks earlier. But they rushed to get the information out because they are quite concerned, and here's why. The variant caused a very - is causing a very fast rise in cases in the city of Pretoria, in South Africa, and it's spreading across the whole country. So just over the course of about two weeks now, this variant went from being essentially undetectable to dominating the outbreak in a major city. Now, during this short time, cases have also cropped up in Bosnia, Belgium, Hong Kong and Israel. So this variant is likely present, at least in low levels, in many parts of the world.
CORNISH: What's the sense about why it's able to spread so quickly?
DOUCLEFF: Yeah, scientists don't know yet, but they believe it has to do with the variant's mutations. And this is actually another reason why they are so worried. This variant has a very high number of mutations - many more than previous variants before it. Dr. Maria Van Kerkhove of the WHO talked about this on Facebook. She says such a high number of mutations is a red flag because they can change the virus's behavior.
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MARIA VAN KERKHOVE: But this is one to watch. I would say we have concern, but I think you would want us to have concern. And I want the viewers to know that we have people who are on this, who are making sure that the right people are having the discussions. And as soon as we have more information to share, we will.
DOUCLEFF: In particular, she says this variant has 38 mutations on the spike protein of the virus. That's the important region of the virus that it uses to bind to cells.
CORNISH: Do scientists know if these mutations are actually changing the behavior of the virus? Like, do they make the virus more transmissible?
DOUCLEFF: Yeah, there isn't enough data yet, for sure, but the variant does have a cluster of mutations that are known to boost transmissibility and several others that can help the virus infect cells more easily.
CORNISH: What about the vaccines? Are there any signs that the vaccines will be less effective against this variant?
DOUCLEFF: You know, that is really the critical question. And there are clues, again, in the virus's genes. The vaccines could be less effective against it. In particular, the variant has multiple mutations that are already known to help the virus evade the immune system, to help it resist antibodies and avoid detection by some of the immune system's front-line defenders.
CORNISH: And scientists probably have to test this out - this variant in the lab, right?
DOUCLEFF: Absolutely. You know, scientists have to take blood from people who have been vaccinated and then see how well the antibodies in their blood work against this variant. You know, can they still kill it? Researchers in South Africa are working at warp speed to figure that out, and hopefully they'll have some data in a few weeks. Before they do, you know, right now, all of this is really speculation.
CORNISH: We are getting the bulk of this information from the World Health Organization. They deem this, quote, "a variant of concern." What else did the agency conclude?
DOUCLEFF: You know, so that meeting was held in private with scientists from South Africa and independent experts on viral evolution. During that meeting, they gave the variant the name, which - Omicron - which, you know, is the highest level designation of variant of concern. And in a press conference, Dr. Van Kerkhove wanted to make sure people realize that these variants will continue to emerge as long as the virus is transmitting freely in unvaccinated people.
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VAN KERKHOVE: So the virus has a lot of room to change. So this is why every single one of you watching has a role to play in driving transmission down, as well as protecting yourself against severe disease and death. So get vaccinated when you can.
DOUCLEFF: And, you know, take precautions to prevent the spread of it if you are vaccinated because you can still get a breakthrough infection.
CORNISH: That's NPR's Michaeleen Doucleff. Thank you.
DOUCLEFF: Thank you, Audie. Transcript provided by NPR, Copyright NPR.