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Health officials had hoped the coronavirus would not be able to tolerate the heat and humidity of summer, that it would soon fade away. Well, it turns out the virus can survive in heat, and it is looking more like the disease will be here year-round and for years to come. NPR's Pien Huang explains why.
PIEN HUANG, BYLINE: Three months ago, the World Health Organization believed that the coronavirus could be contained and wiped out. On March 2, the WHO director-general Tedros Adhanom Ghebreyesus made this declaration.
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TEDROS ADHANOM GHEBREYESUS: Containment of COVID-19 is feasible and must remain the top priority for all countries.
HUANG: Tedros thought there was a chance that we could prevent adding a new disease to the global list. Health authorities were able to stamp out the first SARS virus back in 2004. But at this point, that scenario is unlikely for COVID-19.
Albert Ko is an epidemiologist at Yale and co-chair of the advisory group to reopen Connecticut.
ALBERT KO: So already we've seen it's gone all over the world, and many people are still susceptible to it. So we're going to have this for a long time circulating with us.
HUANG: Malik Peiris, a virologist at Hong Kong University, says the key difference between COVID and SARS is when they're contagious. With SARS, most people didn't start spreading these until they were very sick. With COVID, though...
MALIK PEIRIS: It is transmissible even before people get symptoms. OK?
HUANG: Which makes it a lot harder to contain. By the time people know they're sick, they've already spread it to a bunch of people. Basically, that's what a disease needs to stick around - the ability to keep infecting people. The herpes virus has a clever strategy, Peiris says. Once a person is infected with it, it hides out in their body.
PEIRIS: From time to time, it gets reactivated, comes down and causes a milder disease that allows it to transmit to other people.
HUANG: So one person can keep transmitting the virus throughout their entire life. And while herpes hides in people, Albert Ko from Yale says other viruses hide out in animals, like Ebola.
KO: It's circulating in animals, and it spills over intermittently.
HUANG: Primates and bats carry Ebola. And when the virus comes into contact with people, it can spread quickly and is very deadly. A more mild disease, like flu, has yet another strategy. Peiris says that most people who catch the flu virus get over it and become immune to the strains they were infected with.
PEIRIS: As the population immunity builds up, it has to try to escape in order to survive, so the virus undergoes some mutation.
HUANG: So the flu virus revamps itself constantly, which allows it to dodge our built-up immune system defenses and the vaccines we throw at it. The good news is that the coronavirus doesn't mutate as fast as flu, and it doesn't appear to hide out in the body after the initial infection. But Ngozi Erondu, an epidemiologist and research fellow at Chatham House, says the coronavirus is probably here to torment us for the next couple years at least.
NGOZI ERONDU: One, because it's highly transmissible; two, because we don't have a vaccine and we probably won't have a vaccine for another two years at the minimum.
HUANG: There are billions of people in the world who can still be infected by it. And the only thing between the virus and them is a mask and social distance.
Pien Huang, NPR News.
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