MUSC researchers emphasize masks as tool to reduce COVID infections

July 14, 2020
closeup of a woman wearing a bright blue mask with tiny white flowers staring intently into the camera
Even cloth masks can be helpful in reducing COVID-19, researchers are finding - but only if everyone wears them. Image by Christo Anestev via Pixabay

Unless you’re a superhero who must hide your identity to protect your loved ones from supervillains bent on revenge, wearing a mask on a day-to-day basis isn’t something that Americans usually do. 

But in the topsy-turvy pandemic world we live in, the simple act of wearing a mask is now something you can do to help your community.

Wearing a mask is more than show. Increasing epidemiological evidence indicates that masks, even homemade cloth masks, do help to reduce infections from SARS-CoV-2.

“That's clearly held true in all the publications I’ve read recently, that masks are a big, big key,” said Paula Traktman, Ph.D., dean of the MUSC College of Graduate Studies, who is a virologist by trade.

The critical point is that masks do a better job of keeping an infected person’s germs inside of his or her own mask than preventing germs from getting past a healthy person’s mask. And because of the long incubation period of this particular virus and the way it affects different people in such varied ways, an infected person can walk around for several days before starting to feel sick – or never feel worse than having a mild cold.

“You feel like, ‘Oh, I’m not getting anybody sick. I’m fine.’ But you don’t know that,” Traktman said. “Feeling OK is not a good indication that you don’t have the virus.”

That means that everyone should be wearing a mask when out in public, she said. And while you might be fine after a COVID-19 infection, someone you infect might not be.

"Feeling OK is not a good indication that you don’t have the virus." Dr. Paula Traktman

“Is it worth it to us as a group, in this time of a pandemic, to all wear a mask in the hopes it will help our neighbor or a friend or someone we’ve never even met? Can we collectively adopt this practice out of concern for others even if we don’t all fully believe in it as individuals or find it inconvenient? Are we able to do this for each other given the severity of this infection for some people?” asked Eric Meissner, M.D., Ph.D., an assistant professor in the MUSC College of Medicine Division of Infectious Diseases who’s part of the team responsible for the MUSC COVID-19 Epidemiology Intelligence Project.

No one is saying that cloth masks, surgical masks or even N95 masks are 100% effective at blocking the virus, Meissner said. But as the pandemic has gone on and researchers have gathered more information, they’re finding that masks make a difference.

For example, when researchers looked at COVID-19 mortality rates around the world, they found that countries with older people or greater numbers of people who are obese had higher mortality rates – but so did countries that resisted masks when compared with countries where mask-wearing is a cultural norm or was mandated early.

A modeling study by researchers in the United Kingdom suggests that mask wearing – even if the homemade masks capture only half of exhaled respiratory droplets – can still help control the pandemic at the population level.

“If we were all do this as a society, the odds of transmission go down, and we could see a significant impact of that collective group choice on the rates of infection, even though there would still be some infection,” Meissner said.

That could then help us to open schools and businesses as safely as possible, he pointed out.

“Is it worth it to us as a group, in this time of a pandemic, to all wear a mask in the hopes it will help our neighbor or a friend or someone we’ve never even met? Can we collectively adopt this practice out of concern for others even if we don’t all fully believe in it as individuals or find it inconvenient?" Dr. Eric Meissner

Besides cultural norms, part of the resistance to masks stems from early messages from public health authorities that masks were unnecessary.

Traktman said the early messages given to the public were “very sloppy” and missed a lot of nuance. At that point, authorities worried about having enough N95 masks for health care workers. And because it was a new virus, there were a lot of unknowns. People thought that physical distancing of 6 feet – the generally accepted range of respiratory droplets before they fall to the earth – would be enough to contain the spread, she said. But the experience of Asian countries where masks are more common is showing masks’ utility.

Meissner said there’s a misperception that if you can, for example, smell someone’s perfume while wearing a mask then the mask isn’t doing anything. But respiratory droplets – the droplets exhaled when you cough, sneeze, sing, laugh or yell – are bigger than oxygen and carbon dioxide molecules. That means you can breathe through the mask while it still catches those droplets.

Traktman said she puts her mask on as she gets out of her car each morning and wears it in all common areas of the office, like hallways and the break room. Only when she’s alone in her own office will she take it off, she said.

“I hear all these people say, ‘Oh, I can’t breathe when I have a mask on,’ but you see surgeons wearing masks for eight-, 10-hour operations. Of course you can breathe,” she said.

For a rough test of the efficacy of a cloth mask, she suggested holding it up to the light. The more light it blocks, the tighter the weave and the more effective it is. But the most important thing is to wear the mask properly – covering the nose and mouth – and to wear it consistently.

“I don’t think anybody puts it on and says, ‘Oh, fabulous! What a relief! I’m going to keep doing this after COVID!’ Of course not. But if you find one that fits comfortably, you don’t need four layers of fabric and two coffee filters,” she said. “Much better to find one that feels comfortable on you and wear it than to complain it's not comfortable and not wear it.”

About the Author

Leslie Cantu

Keywords: COVID-19, Research