MADDIE SOFIA: You're listening to SHORT WAVE from NPR.
You also wrote about how this plays into a potential reason why the virus can spread
between people before symptoms show up. Talk to me about that.
ED YONG: Right. So in most respiratory viruses, you either get infections in the upper airways -
in which case symptoms are mild, but the virus spreads more easily -
or you get infections in the lower airways - in which case symptoms are more severe, like pneumonia,
but the virus is harder to transmit. It seems that the new coronavirus can infect both sites.
So perhaps it infects the upper airways, causing mild symptoms and spreading easily
before moving down into the lower airways and causing some of the more severe illnesses we've seen
in the worst COVID-19 cases.
And maybe the reason it can do all those things is that it relies on this furin enzyme,
which is found in lots of different tissues.
SOFIA: Right.
YONG: Now, of course, this is still conjecture.
It's kind of a - if you look at it, it's a plausible story. It makes sense, and it checks out.
SOFIA: Yeah.
YONG: But it could also be completely wrong.
