A previously unknown novel coronavirus capable of infecting people has been discovered in Borneo, says a team of researchers from Duke University.

Transcript

STEVE INSKEEP, HOST:

I was doing some research the other day and found a diary note from one of Abraham Lincoln's Cabinet secretaries. Gideon Welles wrote in 1862 (reading) sensation items are the favorite ones of the press. Alarming predictions delight their readers.

To be clear, this next story is not an alarming prediction, but it does encourage us to think about when a pandemic could come again. A new coronavirus emerges from animals every few years. They don't often cause a pandemic, but they can. So scientists are watching a discovery in Malaysia. NPR's Michaeleen Doucleff reports.

MICHAELEEN DOUCLEFF, BYLINE: Dr. Gregory Gray has spent decades looking for new respiratory viruses that jumped from animals. When SARS-CoV-2 emerged in patients with pneumonia, he wondered if there might be other new coronaviruses out there already making people sick. So he challenged a graduate student to make a test like a COVID-19 test but more powerful.

GREGORY GRAY: We wanted something that would capture everything, a diagnostic that would pick up all the coronaviruses.

DOUCLEFF: Even undiscovered ones. Right off the bat, in the first samples tested...

GRAY: We get a signal.

DOUCLEFF: And it looks unusual. Gray tested the diagnostic on about 300 patients at a hospital in Sarawak, Malaysia. They took swabs from deep inside the patient's noses, like with the COVID test. These patients had what looked like regular pneumonia, but the tool found something else.

GRAY: We discovered evidence that there was a canine coronavirus in specimens from Sarawak.

DOUCLEFF: Did you catch that? They found signs of a canine or dog coronavirus inside patients' respiratory tracts. And it wasn't just in one patient but in eight, mostly kids.

GRAY: That's a pretty high prevalence of viruses - you know, I think 2.7% or something - that were positive. That is remarkable.

DOUCLEFF: So remarkable that Gray actually thought the results weren't real, that perhaps they had made a mistake. Could there really be yet another entirely new coronavirus causing pneumonia in a part of Malaysia and one from dogs? To find out, he sent the samples over to a world expert on coronavirus, Anastasia Vlasova.

ANASTASIA VLASOVA: My title is assistant professor and I'm with The Ohio State University.

DOUCLEFF: When Vlasova saw Gray's data, she didn't believe them. She thought...

VLASOVA: There's something wrong.

DOUCLEFF: Because, she says, dog coronaviruses don't generally jump into people.

VLASOVA: That's right. It's not been reported before.

DOUCLEFF: Nevertheless, Vlasova tried to grow the coronavirus in the lab. She used a special solution or culture she knew worked for other dog coronaviruses. And lo and behold...

VLASOVA: Luckily, the virus grew very well in that culture.

DOUCLEFF: And then with a lot of virus on hand, Vlasova could start to study it closely. She decoded the virus' genes, and she found something disturbing.

VLASOVA: We did discover a very, very unique mutation.

DOUCLEFF: That specific mutation, she says, is only found in human coronaviruses known to make people sick.

VLASOVA: A very similar mutation was previously found for SARS coronavirus and SARS-CoV-2 very soon after their introduction into human population.

DOUCLEFF: This mutation, she says, helps the dog virus infect or persist inside people and may be a key step required for coronaviruses to make the jump into people. Xuming Zhang is a virologist at the University of Arkansas for Medical Sciences. He says more research is needed to say for sure that this virus is causing pneumonia. And it's unknown how common it is or if it's contagious.

XUMING ZHANG: No evidence showing yet transmission from human to human.

DOUCLEFF: But he does think the more scientists look for coronaviruses in sick people, the more they will find.

ZHANG: No, no, I don't think it's any surprise. And I still believe, you know, there's more viruses out there. It's very likely that more animal viruses can transmit to human.

DOUCLEFF: And another outbreak is inevitable. The way to stop a future pandemic, he says, is to do more testing in people and seek out these strange, hidden infections. Michaeleen Doucleff, NPR News. Transcript provided by NPR, Copyright NPR.

Correction

A previous version of this story incorrectly spelled Xuming Zhang's name as Xumin Zhang.