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Health Team

CDC: Masks protect both you and others from coronavirus

Posted November 10, 2020 9:11 p.m. EST
Updated November 11, 2020 7:51 p.m. EST

— Wearing a mask can help protect you, not just those around you, from coronavirus transmission, the Centers for Disease Control and Prevention said in new guidance Tuesday. The statement was an update to previous guidance suggesting the main benefit of mask wearing was to help prevent infected people from spreading the virus to others.

Cloth masks act as "source control" to block virus particles exhaled by the wearer and provide "filtration for personal protection" by blocking incoming infectious droplets from others, the CDC said in its new guidance.

"The relationship between source control and personal protection is likely complementary and possibly synergistic, so that individual benefit increases with increasing community mask use," the CDC said.

"It's a two-way street," Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said Tuesday on MSNBC. "You protect others, their mask protects you, and your mask also protects you."

The new guidance cites a number of studies showing that masks reduce the risk of transmitting or catching the virus by more than 70% in various instances. One study revealed mutual mask-use helped prevent two infected hairstylists from transmitting the virus to 67 clients who were later interviewed. Another followed infected people who spent more than 10 hours on flights without infecting other passengers when masks were used.

In several scenarios, when officials told people to wear masks, infections and deaths fell significantly, the CDC pointed out.

"I think we had a suspicion for a while that you would at least get some minor level of protection from wearing a mask that was conferred to yourself as well as those around you," said Dr. Karen Chilton, WakeMed's associate chief quality officer in Raleigh.

"I believe some of the hesitation around putting that out initially is the CDC is trying to be very careful of giving people a false sense of security – that they could walk around in a mask and do whatever they wanted with a bunch of folks that aren’t being as careful," Chilton said.

The agency cited an economic analysis that found a 15% increase in universal masking could prevent losses of up to $1 trillion.

"Adopting universal masking policies can help avert future lockdowns, especially if combined with other non-pharmaceutical interventions such as social distancing, hand hygiene, and adequate ventilation," the CDC said.

"I definitely think it brings some validation for people who’ve been on the verge or maybe felt like they didn’t have to wear it all the time or every single time they went out," said Sage Staley, a student at the University of North Carolina at Chapel Hill.

Durham has required masks in public for months – even before a mask mandate was issued for North Carolina.

"It’s kind of shunned if you don’t wear a mask," Durham resident Matthew Lunceford Blivin said. "I’m a big runner, and even when I go for a run not wearing a mask, I get a lot of ugly looks."

"It’s not that hard," Blivin added. "It’s definitely inconvenient, but we also have to wear seatbelts."

Some cloth masks are nearly as good as surgical masks at blocking droplets, the CDC said. Polypropylene may generate a static charge that captures particles, the CDC said, while silk might repel moist droplets and be more comfortable.

"Even a simple cloth mask works – the more layers, the better – and those are pretty accessible," said Dr. David Wohl, an infectious disease expert at UNC Health.

"If you can see through the material or blow through it easily and make a candle move, that’s not going to be blocking as well as you can," said Dr. Eric Westman, an associate professor at Duke University's School of Medicine, who recommended using masks with several layers of fabric.

"It does seem to matter how many layers of fabric you have and maybe matters a little bit what type of fabric," Chilton said. "But it also matters on the level of exposure.”

"The mask I would recommend you wearing is the one you’re willing to wear, and that’s especially true for kids," she added. "Whatever mask your kiddo is willing to wear and keep on reliably, covering their nose and mouth, and wear properly to protect their respiratory tract and keep any droplets in is the right mask.”

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