ARI SHAPIRO, HOST:
Here in the U.S., there's a lot of discussion about what it would take for the coronavirus to become endemic - in other words, a more predictable seasonal virus like the flu or common cold. Well, in Africa, top scientists say much of the continent may have already reached that less-threatening phase. NPR's Nurith Aizenman reports.
NURITH AIZENMAN, BYLINE: Like many countries in Africa, before the omicron wave, Malawi didn't seem to have been hit too hard by COVID. Kondwani Jambo is an immunologist at the Malawi-Liverpool-Wellcome Programme. He says even by July of last year, when Malawi had already gone through several waves of the coronavirus, it looked like only a tiny share of Malawians had been infected.
KONDWANI JAMBO: Probably less than 10% - if we look at the number of individuals that have actually tested positive, maybe less than 5%, even.
AIZENMAN: The number of people turning up in hospitals was also pretty low even during the peak of each successive COVID wave. But Jambo knew this wasn't the full picture of what had been going on in Malawi. The country's population is so young.
JAMBO: The median age for them from Malawi is something like 17.5.
AIZENMAN: But most infections were probably asymptomatic ones that wouldn't show up through testing, let alone in hospitals. So Jambo and his collaborators turned to another potential source of information, a repository of blood samples that had been collected from Malawians month after month by the national blood bank. And they checked what share of those samples had antibodies for the coronavirus. Their findings...
JAMBO: Well, me, I was very shocked.
AIZENMAN: By the start of Malawi's third COVID wave with the delta variant last summer, as much as 80% of the population had already been infected.
JAMBO: There's absolutely no way we would have guessed that this thing has spread that much.
AIZENMAN: Jambo thinks these findings explain a key feature of the current omicron wave. The number of deaths this time has been a fraction of the already low number during previous waves. Now, barely any Malawians have been vaccinated, so Jambo says their apparent resistance to severe disease was likely built up as a result of all the prior exposure to earlier variants.
JAMBO: Now we have had beta. We have had delta and the original. It seems a combination of those three has been able to neutralize this omicron variant in terms of severe disease.
AIZENMAN: And now that the omicron wave has peaked across Africa, country after country there seems to have experienced the same pattern - a huge rise in infections that has not been matched by a commensurate spike in hospitalizations and death. Shabir Madhi is a prominent vaccine allergist at the University of Witwatersrand in South Africa.
SHABIR MADHI: I think we should draw comfort from the fact that this has been the least severe wave in the country.
AIZENMAN: And he says there, too, the most likely reason is that immunity gained through prior infections. In South Africa's case, it came at a high price. Its population is substantially older than Malawi's, and during the delta wave last summer, hospitals in South Africa were swamped. Still, the upshot, says Madhi...
MADHI: We've come to a point where at least three quarters - and now after omicron, probably 80% of South Africans have developed immunity and at least protection against severe disease and death.
AIZENMAN: He and other scientists aren't quite ready to say the coronavirus no longer poses a danger in Africa. Emory University biologist Rustom Antia has been studying what it will take for the coronavirus to become endemic the way the flu and seasonal colds are.
RUSTOM ANTIA: So the key question is, how long does immunity that protects us from getting ill last?
AIZENMAN: But Shabir Mahdi says research suggests it could last at least a year. So Madhi says in African countries and likely in many other low- and middle-income countries with similar experiences of COVID, the takeaway is already clear.
MADHI: I think we've reached a turning point in this pandemic. What we need to do is learn to live with the virus and get back to as much of a normal society as is possible.
AIZENMAN: That still means taking steps to protect the vulnerable, says Mahdi. But he adds any policy that's intended to stop future infections with massively disruptive restrictions isn't just unnecessarily damaging, but he says it's fanciful thinking.
Nurith Aizenman, NPR News. Transcript provided by NPR, Copyright NPR.
