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Experts say the effectiveness of a mask is less important than the number of people who wear them. Noam Galai / Getty Images
  • Researchers say they’ve designed a new chemically treated mask that may sanitize up to 82 percent of respiratory droplets from the new coronavirus, SARS-CoV-2.
  • Experts say the potential mask is encouraging news, but they also urge people to continue wearing face coverings that are currently available.
  • They say masks should contain two or more layers of washable, breathable fabric, completely cover the nose and mouth, and fit snugly against the sides of the face.

Researchers say they’ve developed a chemically treated mask that could sanitize respiratory droplets containing the coronavirus that causes COVID-19.

The proof-of-concept design from researchers at Northwestern University in Illinois uses modified fabric treated with the antiviral chemicals phosphoric acid and copper salt.

In a simulation, the scientists said their mask sanitized up to 82 percent of escaped respiratory droplets.

“These results suggest that the chemical modulation of respiratory droplets, when used in conjunction with face covering, could bring significant additional benefits to mitigate the spread of infectious respiratory diseases, especially for those transmittable through pre-symptomatic or asymptomatic carriers such as COVID-19,” the researchers wrote in the journal Matter.

Experts say the chemically treated masks could potentially be effective, but they shouldn’t distract from the basics of mask wearing.

“If such a mask is truly effective, affordable, nontoxic, and more comfortable to wear than the masks currently available, I could see it being most helpful for people who do not wear masks on the basis of breathability,” Dr. Anne Liu, an infectious disease physician at Stanford Health Care in California, told Healthline.

“However, I caution against getting too fancy with standard practice if these novelties distract from the basics, i.e., the workhorses of infection prevention: standard masks, hand hygiene, ventilation, and reasonable distancing,” she added. “Widely available surgical masks and multilayered cloth masks work very well to prevent viral transmission.”

The new coronavirus is believed to spread through close contact between people.

When a person with the virus coughs, talks, sneezes, and breathes, they produce respiratory droplets that others can then inhale, causing an infection.

The Centers for Disease Control and Prevention (CDC) states that mask wearing is a crucial tool in stopping the spread of COVID-19.

The agency advises that everyone over the age of 2 years old wears a mask in public and when around people who don’t live in their household.

The Northwestern University researchers say their chemically treated masks are at proof-of-concept stage and more research is needed.

Dr. William Schaffner, an infectious disease expert at Vanderbilt University in Tennessee, says if the chemically treated masks are proven to be effective and can be made cheaply, he would consider wearing one.

But he argues that regular surgical masks currently available help stop the spread of the virus without the need for enhancements.

“A regular surgical mask substantially reduces the transmission of exhaled virus. It also offers some protection against inhaled virus. It works in both directions, but it’s principle function is to prevent you, who might be infected, from infecting others,” Schaffner told Healthline.

“Wearing a mask is fundamental to the reduction in transmission of the COVID virus,” he said. “It is the single most important thing all of us can do to inhibit the spread of the virus.”

“One can be totally without symptoms but nevertheless infected and therefore contagious, and that is the origin for the recommendation that we all wear masks,” Schaffner said.

“It is the simplest thing all of us can do. It’s cheap, it’s easy to do, and although it’s inconvenient and unusual for us to do this, it also turns out to be very effective,” he added.

In some cases, it’s still possible for respiratory droplets to escape standard surgical masks.

“We know from previous experience with COVID and viruses closely related to COVID, such as SARS1 and MERS, that the standard surgical masks prevented the wearer from getting infected in about two-thirds of the cases, so this would suggest that in about one-third of the cases, it did not protect,” Dr. Dean Blumberg, head of pediatric infectious disease at the University of California, Davis, told Healthline.

“The standard surgical mask has gaps in the sides where the air can go in,” he explained. “There’s a gap in the bottom and there may be a gap at the top, and because of those gaps, the wearer may not have a tight seal.”

The masks designed by the Northwestern researchers sanitized 82 percent of droplets in a simulation.

Blumberg says this would be an improvement on regular masks.

“It would be a step up from the 67 percent of protection that we currently get with standard surgical masks. So that would be an improvement, it would be a significant, incremental improvement,” he said.

All of the experts Healthline spoke with emphasized that innovation and advancements in the prevention of COVID-19 are important, but so is ensuring people wear their masks to begin with.

“I think first of all, at least in the U.S., I would just like everybody to wear a mask,” Blumberg said.

“That’s the lower-hanging fruit, is getting people to wear masks and then once they wear masks, then the next step is to wear masks that will be more effective in reducing transmission both to the person wearing the mask and to the person who may be infected — and for that we already know that the N95 masks are highly effective without having this antiviral activity on them,” he said.

Currently, there’s a worldwide shortage of N95 masks. The CDC advises that only healthcare workers should wear them and not members of the general public.

For the general public, the CDC says masks should have two or more layers of washable, breathable fabric, completely cover the nose and mouth, and fit snugly against the sides of the face with no gaps.

Schaffner says a good mask is one that you can hold up to light and not see through. But he argues the most effective mask is one that will be worn.

“Whatever mask you use, it has to be worn. Leaving it on the bureau won’t help reduce the transmission of the virus. You’ve got to wear it when you’re around other people,” he said.

Part of the problem with mask resistance, experts say, is people in the United States aren’t used to wearing masks, unlike others in many Asian countries.

“The third wave of the virus tearing across the country right now is not a problem of masks not working. It’s primarily a problem of people not wearing masks. My impression is that mask objectors are not objecting to their breathability. They seem to object to their visibility,” Liu said.

“We don’t have to use fancy, high-tech masks, but if these masks with antiviral compounds gained traction with people who otherwise wouldn’t wear masks, then they could be an additional tool to fight the pandemic. We could use more tools, but we also need to stay focused on the basics,” she added.