AILSA CHANG, HOST:
As we just heard, even though most face masks make lip reading harder or cover a smile, we've been told again and again to wear them because wearing a mask lowers the chances that you will spread COVID-19 to others. But a growing body of evidence suggests that the opposite is also true. That is wearing a mask might protect you, too. Here to walk us through the research is Dr. Monica Gandhi, an infectious disease specialist at the University of California, San Francisco.
MONICA GANDHI: Thank you very much for having me.
CHANG: All right. So briefly walk us through the theory here. How are masks also beneficial for the people wearing them?
GANDHI: Right. So as you said, they're very beneficial to protect others because you shed at high rates from your nose and mouth even when you feel fine. So that had been kind of the party line for a while. But they really are protective of you as an individual. And sort of putting it all together, it really is that the less virus that you get in, the less sick you're likely to be. So not only do masks protect you - and we've seen from getting the virus and altogether. And that's been seen in hamster studies. That's been seen in a health care worker study that was just published last week in JAMA. But if you do get the virus in, you get very little in. And you're likely to get what's called an asymptomatic infection or not have any symptoms at all and - or a very mild infection. So it really is based on the fact that we've known for many years now - probably a hundred - that the more virus you get into your system, the more likely you are to get sick. And these masks protect you.
CHANG: Oh, that's so interesting. So if mask wearing does turn out to lower the severity of the disease because you're lowering the amount of virus that you're taking in, would that translate then to fewer deaths?
GANDHI: Yes. So it really looks like any country that has adopted universal mask wearing - and many, many countries have - even as they open up and they're seeing each other more and there's more cases, it has led to much, much fewer deaths or severe illness. So the idea about this virus is it's completely bizarre how it can cause no symptoms in some people and very, very severe symptoms in others.
GANDHI: And what we want to do by wearing a mask is get down the bad stuff about this virus that it can cause very severe illness. And, yes, we've absolutely not only seen that in countries but even in settings where there are outbreaks but everyone masked, there's, like, a 95% rate of not having symptoms at all. There was actually a outbreak in a chicken factory, outbreak in a seafood factory in this country. But everyone was masking. And it was 95% asymptomatic rate of infection.
CHANG: Oh, that is fascinating. I mean, mask wearing has become divisive, right? It's a political issue in many parts of the country. Do you think this evidence could help change the public-health messaging around masks by appealing to people's self-interest?
GANDHI: Yes. I think that I - what I'm hoping for is that I do understand that politics always gets into everything. This will protect you, your family as well as others. This will protect you. That means that we should all be wearing a mask because we need to get through this pandemic. We are miserable. This is taking a long time. And if we...
GANDHI: ...All put this over our faces, we will get through it faster.
CHANG: All right. That is Dr. Monica Gandhi. She is a professor of medicine and the director of the UCSF Center for AIDS Research.
GANDHI: Thank you.
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