POST 128. February 14, 2021. CORONAVIRUS. “The Centers for Disease Control and Prevention released new research on Wednesday that found wearing a cloth mask over a surgical mask offers more protection against the coronavirus, as does tying knots on the ear loops of surgical masks…

…Those findings prompted new guidance on how to improve mask fit at a time of concern over fast-spreading variants of the virus.

For optimal protection, the CDC says to make sure the mask fits snugly against your face and to choose a mask with at least two layers…

In laboratory testing, researchers simulated coughs and breathing and tested how well different masks worked to block aerosol particles — comparing no mask, a cloth mask or a surgical mask. They also tested two methods to optimize the fit of cloth and medical masks: wearing a cloth mask over a surgical mask, and tying knots on the ear loops of surgical masks and then tucking in and flattening the extra material against the face.

Both methods produced substantially improved protection against transmission of and exposure to infectious aerosols.

“In the study, wearing any type of mask performed significantly better than not wearing a mask,” said CDC Director Rochelle Walensky in a briefing from the White House COVID-19 Response Team on Wednesday.

“And well-fitting masks provided the greatest performance at both blocking emitted aerosols and exposure of aerosols to the receiver. In the breathing experiment, having both the source and the receiver wear masks modified to fit better reduced the receiver’s exposure by more than 95%, compared to no mask at all,” she said…

The CDC’s guidance on improving mask fit now recommends:Choosing a mask with a nose wire, which prevents air from leaking out along the top

Using a mask fitter or brace over a disposable or cloth mask, to prevent air from leaking out. These small, reusable devices cinch a cloth or medical mask to create a tighter fit and improve mask performance, Walensky said.

Make sure your mask fits snugly over your nose, mouth and chin: “If the mask has a good fit, you will feel warm air come through the front of the mask and may be able to see the mask material move in and out with each breath,” the CDC says.

Add layers of material – either by using cloth mask with multiple layers of fabric or by wearing a disposable mask under a cloth mask.

But double-masking isn’t recommended for all masks. Don’t combine two disposable masks, the CDC says: “Disposable masks are not designed to fit tightly and wearing more than one will not improve fit.”

And don’t layer another mask on top of a KN95, either. That mask should be used alone, the CDC says.” (A)

“To ensure proper mask-wearing, the CDC recommendations include:

Choosing a mask that has two or more layers of washable, breathable fabric

Putting the mask over your nose and mouth and securing it under your chin

Knotting the ear loops of a surgical mask, where they attach to the mask, and then tucking in and flattening the extra material close to the face (knotted and tucked masks)

Fitting the mask snugly against the sides of your face, and slipping the loops over your ears or tying the strings behind your head

If you have to continually adjust your mask, it doesn’t fit properly, and you might need to find a different mask type or brand.

Wearing your mask under your scarf, ski mask, or balaclavain cold weather

Keeping a spare mask to replace one that becomes wet

Storing wet reusable masks in a plastic bag until they can be washed” (B)

“The guidance comes at a potentially perilous moment, as health officials race to vaccinate tens of millions of people to protect them from more transmissible and possibly more lethal variants but remain hampered by a limited vaccine supply.

It also represents a new administration’s effort to present clear masking guidelines after mixed messaging and the politicization of the issue appear to have bewildered many Americans. Early last year, health officials did not urge their use because of concerns health workers would be unable to get them. Even after health officials reversed course last April after realizing that people without symptoms were driving the virus’s spread, President Donald Trump refused to wear a mask and ridiculed those who did. In part as a result, many Americans still disdain them.

CDC Director Rochelle Walensky acknowledged at a White House briefing Wednesday that some people may be “both tired of hearing about masks as well as tired of wearing them.” She noted that “masks can be cumbersome, they can be inconvenient.”

Conceding the changing guidance since the start of the pandemic, Walensky said that knowledge about the virus has evolved over time.

“The science is clear,” she said. “Everyone needs to be wearing a mask when they’re in public or when they are in their own home but with people who do not live in their household. This is especially true with our ongoing concern about new variants spreading in the United States.”

Walensky said that research shows that coronavirus infections and deaths have decreased when policies mandating masks are implemented. “With cases, hospitalizations and deaths still very high, now is not the time to roll back mask requirements,” she said…

Other experts expressed concern that double masking could discourage mask-wearing.

“I would rather people focus on finding one quality mask that meets the mark, versus trying to layer masks and create discomfort, difficulty breathing … or frustration that might lead to no mask at all,” said Saskia Popescu, an infectious-disease epidemiologist and assistant professor at George Mason University.” (C)

“Doubling up may do more harm than good if they give you a false sense of security, leading you for example to spend more time with strangers indoors or slip up on social distancing.

“You cannot become overly reliant on any one measure,” WHO infectious disease specialist Maria Van Kerkhove said during an October media briefing. “It can’t just be testing alone, it can’t just be case identification alone, it can’t just be masks alone, it can’t just be physical distancing alone. All of these different interventions need to be used.”” (D)

“Dr. Brooks cautioned that the new study was based on laboratory experiments, and it’s unclear how these masking recommendations will perform in the real world (the experiments used three-ply surgical and cloth masks). “But it’s very clear evidence that the more of us who wear masks and the better the mask fits, the more each of us benefit individually.”

Other effective options that improve the fit include using a mask-fitter — a frame contoured to the face — over a mask, or wearing a sleeve of sheer nylon hosiery material around the neck and pulled up over a cloth or surgical mask, the C.D.C. said.

Even as vaccines are being slowly rolled out across the country, the emergence of the new variants, which may respond differently to treatments or dodge the immune system to some degree, has prompted public health officials to emphasize that Americans should continue to take protective measures like masking.” (E)

• A.CDC Says Double-Masking Offers More Protection Against The Coronavirus, by LAUREL WAMSLEY, https://www.npr.org/sections/coronavirus-live-updates/2021/02/10/966313710/cdc-now-recommends-double-masking-for-more-protection-against-the-coronavirus
• B.CDC: Proper Double-Masking Raises COVID Protection, By Lindsay Kalter, https://www.webmd.com/lung/news/20210210/cdc-proper-double-masking-raises-covid-protections
• C.Masks should fit better or be doubled up to protect against coronavirus variants, CDC says, by Lena H. Sun and Fenit Nirappil, https://www.washingtonpost.com/health/2021/02/10/cdc-double-masks-covid/
• D.How to know when you should double-mask, when one mask is enough, and which masks you should use, by Anna Medaris Miller, https://www.businessinsider.com/are-two-face-masks-better-than-one-2020-10
• E.The CDC Says Tight-Fit Masks or Double Masking Increases Protection, By Roni Caryn Rabin and Sheryl Gay Stolberg, https://www.nytimes.com/2021/02/10/world/double-mask-protection-cdc.html?referringSource=articleShare
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