Why you should change your mask as the omicron variant spreads

(CNN) -- As the highly contagious variant of the omicron coronavirus continues to spread, some experts say it's time to reconsider your mask options, especially if you're still wearing the cloth variety.

"Cloth masks are little more than facial decorations. There is no place for them in omicron light," said Dr. Leana Wen, a CNN medical analyst and visiting professor of health policy and administration at the School of Health Institute. Milken of the George Washington University.

"This is what scientists and public health officials have been saying for months, many months in fact," Wen added in a separate telephone interview.

"We need to wear at least a three-layer surgical mask," she said, which is also known as a disposable mask and can be found in most pharmacies and some supermarkets and retail stores. "You can wear a cloth mask on top of that, but don't just wear a cloth mask."

Ideally, in crowded places, "you should wear a KN95 or N95 mask," which can be as cheap as a few dollars each, Wen added. By having a better fit and certain materials, such as polypropylene fibers, that act as mechanical and electrostatic barriers, these masks prevent tiny particles from entering the nose or mouth and must fit the face to work properly.

The guideline changes

During the early months of the pandemic, health experts discouraged the general public from purchasing N95 masks as medical professionals faced a shortage of personal protective equipment. But it has been "many months since N95 supply was an issue," Wen said.

However, the most recent guidance from the US Centers for Disease Control and Prevention on the proper selection, use, cleaning, and storage of face masks recommended that people avoid N95 masks and instead instead chose masks with two or more layers of breathable, washable fabric, something Wen calls "a big mistake."

"If we're going to go so far as to say masks are required, when we don't come from a mask-wearing culture and people don't like wearing masks, at least recommend that they wear the most effective masks," Wen said.

Other countries, including Germany and Austria, "changed their standard to say that a face covering that must be worn in public must be at least a medical-grade surgical mask" in certain settings, she added.

CNN has asked the CDC for comment on its recommendations regarding N95s and cloth face coverings and is still awaiting their response.

Another factor driving the change in mask recommendations is a better understanding of Covid-19 and how it spreads, said Erin Bromage, an associate professor of biology at the University of Massachusetts Dartmouth. "People are slower to appreciate the nature of airborne infections, which is not necessarily a hybrid infection, for example, with influenza, where it can be spread by droplets, inhaled a little bit, on surfaces and infect from other sources." that way". he said. "It appears that ... the main driver of (coronavirus) infection is shared air."

Cloth masks, encouraged early in the pandemic, can filter large droplets, while the most effective ones, such as N95s, can filter both large droplets and smaller aerosols or potentially virus-laden airborne particles if people are around. infected, Bromage said. A cloth face covering also has 75% inward and outward leakage, which the American Conference of Governmental Industrial Hygienists defines as the "percentage of particles entering the facepiece" and the "percentage of particles exhaled by a source coming out of the mask", respectively.

Properly fitted N95 respirators approved by the US National Institute for Occupational Safety and Health can filter up to 95% of airborne particles, according to the CDC. Surgical or disposable masks are about 5% to 10% less effective than N95 respirators, Bromage said, depending on their classification by ASTM International, which has types 1, 2 and 3 to classify only surgical masks of lesser to more effective.

Why the omicron variant has been so successful in rapidly infecting so many people is "unknown at this time," but it only underlines the role quality masks can play, she Bromage said.

"If less virus is needed, or if a person who is infected is shedding more virus, then the role of a mask in this is if we can reduce the amount that you're actually breathing in, you'll get more time," he added. "If you needed 1,000 viral particles to get infected and you're using something that reduces 50% of the stuff, now it's going to take twice as long to get to those 1,000. If you're using one that's 90% efficient, it's going to take at least 10 times as long." before you get infected when you're around someone (who's infected)."

"We need to promote better, high-quality masks everywhere, because right now a single-layer cloth mask is not enough against omicron," said former US Surgeon General Dr. Jerome Adams.

Change your cloth masks

The National Institute for Occupational Safety and Health has a list of approved N95 respirators, which can be found at some home improvement stores, retailers, and drug stores. These masks should be cup-shaped, flat-folded, or duck-billed; two straps that go around your head; an adjustable wire nose bridge; and the appropriate markings indicating NIOSH approval, says the CDC.

The agency also has resources to determine if an N95 respirator is counterfeit and how to properly put it on, take it off, and perform a respirator seal check.

The difference between N95 and KN95 respirators is where the mask has been certified, according to the Oklahoma state department of health. The United States certifies N95s, while China approves KN95s. Approximately 60% of KN95 respirators in the US are counterfeit and do not meet NIOSH requirements, according to the CDC. The CDC has a list of signs that a KN95 respirator has not been approved by NIOSH.

"If they're built to the standard and certified by the appropriate boards in your country like NIOSH here, they all basically do the same thing," Bromage said. "But there are a lot of knockoffs that aren't certified on the KN95 side of things, that may meet the standards but aren't certified to meet it. And there are others that clearly don't."

These experts' recommendation to wear better masks is not a suggestion to throw cloth masks in the trash or "go maskless" when you don't have a medical-grade mask available.

In studies of various face masks, multi-layer, higher thread count cloth masks "have shown superior performance compared to single layers of lower thread count fabric," but remain less effective than high-grade masks. doctor, according to the CDC. Wearing a cloth mask over a medical procedure mask, as Wen suggested, can better protect you and others by improving fit and thus filtering ability, the CDC says.

"If all you have is a cloth mask, it's better than nothing," Wen said. "But you're not well protected, and you should know that you're not well protected. So if you go to a crowded indoor venue and all you have is a cloth mask, don't go."

If you can't buy medical-grade masks for whatever reason, go to places that require masks and give them away for free, like some train stations, grocery stores or businesses, and ask for a surgical mask, Wen suggested. .