Concept image of COVID-19 cells (variants Gamma, Delta, and Omicron). For a long time, scientists couldn’t figure out where Omicron had come from. Now, studies appear to point to one specific group.
Matt Anderson Photography/Getty Images
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Matt Anderson Photography/Getty Images
Concept image of COVID-19 cells (variants Gamma, Delta, and Omicron). For a long time, scientists couldn’t figure out where Omicron had come from. Now, studies appear to point to one specific group.
Matt Anderson Photography/Getty Images
Early in the beginning of the COVID-19 pandemic, scientists predicted the coronavirus would mutate slowly. They were wrong.
Hundreds of thousands of viral mutations and multiple seasonal waves later, researchers now know why.
Turns out, SARS-CoV-2 — the virus that causes the disease COVID-19 — was making evolutionary leaps and bounds in one specific group of people.
“When the virus jumps from person to person, it gets about two mutations a month,” says Sarah Zhang, a health writer for The Atlantic, who has been covering the coronavirus pandemic since it began.
In February, she wrote a piece comparing several studies indicating that in the immune system of an immunocompromised person, the SARS-CoV-2 virus might survive for weeks, even months.
“The more time you have, the more mutations you can accumulate,” Zhang says. “It’s almost like a training camp for the virus to find ways to hide from our immune system.”
In other words, the virus has the opportunity to “try out” different mutations, different attacks against the human immune system. Those mutations, in turn, may help it spark a new wave of infections.
That’s almost certainly what happened with omicron. Understanding it could help us predict the evolution of other viruses in the future.
Want to hear more virology or human biology stories? Let us know by emailing shortwave@npr.org.
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This episode was produced by Hannah Chinn and edited by our showrunner, Rebecca Ramirez. Tyler Jones checked the facts. Robert Rodriguez was the audio engineer.
