Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said that when it comes to using two masks to protect against the coronavirus, “it makes sense” that more than one layer of mask is more effective.
There is no specific research on how facial coverage works against new variants of the virus, including the most transmissible variant in the UK, which has been detected in at least 22 states in the United States.
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A mask “is a physical cover to prevent droplets,” Fauci said on Monday on NBC’s “TODAY” program. “So, if you have physical coverage with one layer, you add another layer, it makes sense that it’s more effective.”
Asked at a meeting at the White House last week whether the new variant would make the masks less effective, he said that, on the contrary, the variants are “the reason why you should absolutely wear a mask”.
Dr. Marybeth Sexton, an assistant professor of infectious diseases at Emory University School of Medicine in Atlanta, agrees with Fauci’s view.
The new variants “can cause people who have them to have a greater amount of virus in their nose, in their mouth, so that when they breathe or speak or cough or sing, they can release more viral particles in the environment than the average person”, she said.
But, added Sexton, “it shouldn’t be much of a problem if everyone has a mask on.”
If used correctly, facial coverings should help prevent the spread of any respiratory virus, regardless of the variant.
“If that wasn’t obvious six months ago, it certainly is now,” said Cameron Wolfe, an infectious disease specialist and associate professor of medicine at Duke University School of Medicine.
Which mask should you wear?
The key is to find a balance between comfort and effectiveness.
“If you put on three or four masks, it will filter better because they are more layers of tissue,” said Dr. Scott Segal, chair of anesthesiology at Wake Forest Baptist Health in Winston-Salem, North Carolina. “But you’re going to take it off because it’s uncomfortable.”
Segal has been studying facial covering tissues for much of the past year in response to the pandemic. Overall, he said, medical-grade three-layer surgical masks tend to offer the best protection for the average individual.
For those who choose fabric masks, Segal recommends “two layers of high quality cotton material with a relatively high number of threads”.
The acceptance of facial coverage has come a long way in the past year. Americans increasingly use them as a way to make fashion statements or to show love for their favorite teams.
Consequently, the mask-making industry has exploded with little supervision. There is no standardized tool – such as one that is equivalent to a nutrition information label on food – for consumers looking to measure mask quality.
Technically, the Food and Drug Administration regulates masks, including tissue coverings for the face, but only when they are marketed specifically for “medical purposes”. Most companies do not explicitly advertise their products as such (in fact, many claim that their masks are not for medical use), placing the burden on consumers to decide which one can offer the most protection.
The gold standard N95 mask is not recommended for the average person, according to the Centers for Disease Control and Prevention, and should instead be reserved for healthcare professionals.
“You could have a very good N95 mask, but let’s say someone isn’t wearing it correctly or just wearing it 50 percent of the time,” said Dr. Leana Wen, an emergency physician and former Baltimore health commissioner. “I would prefer someone to wear a surgical mask or tissue mask 100 percent of the time, correctly and consistently.”
Last year, the FDA authorized the Chinese version of the N95, called KN95, for emergency use. However, counterfeit versions of KN95 flooded the market. The National Institute for Occupational Safety and Health, part of the CDC, has a detailed visual list of counterfeit marks.
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An easy way to test cloth masks at home is to hold them against the light. If the light shines between the individual fibers of the tissue, it probably means that the viral particles can also pass through, said Segal.
His research, which has not yet been peer-reviewed or published in a newspaper, also found that adding a piece of flannel between layers of cotton can also be an effective way to filter out viral particles. This can be added to masks that come with an opening in the middle so that users can enter an additional filter.
Segal did not recommend the use of coffee filters or industrial-grade vacuum filters, citing the lack of evidence that they work well to filter viral particles properly. Other filters, such as PM2.5 filters, will not block viral particles, but can be counted as an additional layer in a mask.
No matter what type of mask is used, the most important thing is to use it correctly.
“I care more about people wearing masks on their chin, without covering their mouth and nose, than what the mask is made of,” said Dr. Richard Besser, president of the Robert Wood Johnson Foundation and former acting director of the CDC.
In fact, “the best quality mask is, frankly, the one you wear the right way the longest when you’re interacting with others,” said Wolfe of Duke University.
Facial covers should extend from the top of the nose to the chin, with no slits on the sides.
“If your nose is out, it is totally useless,” said Segal.
Other tips include:
- Avoid valve masks. Segal said that although the valve allows for easier breathing, it defeats the purpose of wearing a mask because it allows viral particles to come out, putting other people at risk
- Keep extra masks handy in case one breaks or gets dirty
- Hard plastic face shields should not be used as tissue substitutes or medical masks, according to the CDC.
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