The Coronavirus Is Mutating Relatively Slowly, Which May Be Good News

As a virus makes copies of itself, errors may creep in, changing its genetic makeup. Researchers are trying to determine if the changes are significant in the new coronavirus.

AILSA CHANG, HOST:

There is a little bit of good news about the coronavirus. Researchers say that as it spreads across the world, it's changing its genetic makeup only slightly. NPR's Pien Huang explains.

PIEN HUANG, BYLINE: Viruses change up small parts of their genetic codes all the time. Vineet Menachery, a virologist at the University of Texas Medical Branch, says the coronavirus is no different.

VINEET MENACHERY: Yes, viruses are mutating. It doesn't mean that they're going to become more virulent or more deadly.

HUANG: When a virus infects someone, it uses their cells to make copies of itself. Those copies spread to more cells and can be coughed out to infect other people. All viruses make small changes when they replicate, but Menachery says that the coronavirus is actually mutating pretty slowly.

MENACHERY: Their genomes are relatively stable. You know, the mutations that they incorporate are relatively rare.

HUANG: And that's a good thing. Other viruses like flu change much more quickly, making them harder to prevent through vaccines. So far, the coronavirus seems to be picking up about two mutations each month. Flu makes changes about two or three times faster.

Justin Bahl is an evolutionary biologist at the University of Georgia. He says the small changes researchers are seeing don't seem to affect how the virus functions.

JUSTIN BAHL: At this point, the overall genetic diversity I think is actually pretty low. The viruses themselves are not actually under much pressure to change.

HUANG: Bahl says its stability and slower mutation rate are good news for researchers working on treatments for the disease and on vaccines to keep people from getting coronavirus.

BAHL: Within the next year or two, I don't think that the mutations will occur fast enough to drift away from the vaccines.

HUANG: So once a vaccine is developed, it would likely protect people for a couple years at least. Ewan Harrison, a microbiologist at the University of Cambridge, says the small genetic changes the coronavirus is making actually help researchers figure out where the virus is spreading.

EWAN HARRISON: If it's transmitting in hospitals, if it's transmitting out in the community, what the major hopes for transmission are.

HUANG: Tracking the virus is important because while it's not changing significantly right now, that trend may not continue. It could mutate to become more infectious, but it could also become less dangerous or even peter out. The only way researchers will know is by keeping a close eye on it.

Pien Huang, NPR News.

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