In recent months, as new and more-transmissible variants of the coronavirus have emerged, public figures such as US President Joe Biden and infectious-disease expert Anthony Fauci have been seen wearing two face masks.
And as the trend made headlines and became more popular, health officials have recently clarified that while the tactic could be useful, it is not yet one borne of official health guidance but rather a "common sense" measure.
"You probably have seen me wearing a double mask . . . it certainly can't hurt and might help, but it doesn't yet reach the point of an official recommendation from the CDC because of the lack of data," Fauci said on Tuesday in a Washington Post Live interview when asked about the possibility of a double-masking recommendation by the Centers for Disease Control and Prevention.
Last week, CDC Director Rochelle Walensky said in a CNN Town Hall alongside Fauci that double masking is not necessary if you are wearing a single mask that fits and is made of at least two layers of fabric.
"The CDC does not recommend that you must wear two masks, nor does the CDC recommend that you have to wear an N95 mask," Fauci said. "They just say, the most important thing is get everybody to wear a mask." But Fauci also told Post Live on Tuesday that it "is possible" that the CDC could recommend double masking, and that the agency is gathering data about the practice of wearing two masks.
In a world where many people improperly use ill-fitting masks and N95 masks are still in short supply, it may be tempting to double up your protection - especially on planes, which do not allow for consistent social distancing and have seen outbreaks spread by unwittingly infected passengers.
Like Fauci, other experts say it can't hurt - but they also say it is unlikely to replace new guidance for masking while travelling any time soon, and that double masking is not the only wise option to consider.
For now, official guidance by the CDC is being enforced by airlines and airports beginning this week as a result of Biden's executive order mandating masks for travel. The guidance states that "a properly worn mask completely covers the nose and mouth" and that "cloth masks should be made with two or more layers of a breathable fabric that is tightly woven (i.e, fabrics that do not let light pass through when held up to a light source)."
All face coverings, including gaiters, should have two layers and "fit snugly but comfortably against the side of the face," and "should be a solid piece of material without slits, exhalation valves, or punctures."
That does not mean, however, that airlines can't set their own rules for masks. German airline Lufthansa, for example, recently changed its mask rules to require all passengers wear a medical grade mask. "Masks made of fabric will no longer be permitted," as of February 1, according to the airline's website.
The CDC parameters for a fitted face covering, doctors say, are the bare minimum for airplanes, which can lack other important protective measures like consistent social distancing. Shira Doron, an infectious-disease physician and hospital epidemiologist at Tufts Medical Center in Boston, said that she advises anyone who needs to get on a plane use eye protection in addition to an even more greatly layered face mask.
"The issue with travelling is not being in control at all times over your distancing from other people," Doron said. She recommends "a full face shield, with a very good quality three-layer cloth mask with a metal bar in the nose [that has] no gaps." Doron recommends tightening the ear loops on any face covering that does not fit tightly.
David Freedman, an epidemiologist at the University of Alabama at Birmingham, said he would use his medical-grade personal protective equipment (PPE), which is hard for the general public to obtain. "The best masking strategy, which is standard practice for all health-care workers working on units with actual Covid patients, is an N95, then a [surgical] mask on top of that, and then eye protection; goggles or face shield on top of that," Freedman said. "If I were flying on a plane and was not vaccinated, that is what I would be wearing."
The overall strategy, experts say, is to have multiple layers of protection between you and other people, which is why single-layer cloth masks are insufficient.
"If it makes you feel better to do two masks, the chances are you're going to get an enhanced protection, so why not go ahead and do it?" Fauci said on Tuesday.
The debate about double masking intersects with the debate about N95 masks, which are the most protective, medical-grade option. Doron calls N95s "the Cadillac" of masks. But she and a range of experts also say they should not be recommended nationally because of a scarcity of them in hospitals, where they are still most needed. Health officials also worry that their tight fit could result in less overall public mask use.
Walensky of the CDC has said the agency is mindful that N95 masks are difficult to wear at length - and therefore, if recommended, could see people who opt for them taking them off for breaks. "They're very hard to breathe in when you wear them properly," Walensky said last week. "They're very hard to tolerate when you wear them for long periods of time."
Fauci concurred Tuesday, saying N95 masks, even if available, might not be practical for the general public.
Doron said that while she uses a professionally fitted N95 mask at work, as all medical staff do, she would not advise anyone to use one outside of a hospital setting. "If I were [travelling] I would want medical-grade PPE to protect myself, right?" Doron said. "And yet I hesitate to recommend that anybody who is not a healthcare worker wear an N95 mask, because we need it so badly in the hospital."
"Having them be provided by airlines to passengers I think would be an appropriate use," Doron said. "Any scenario where people can't properly distance is an appropriate use potentially of medical-grade PPE, but not right now because of supplies."
While N95s could eventually become a useful tool if there are enough of them, right now the next best thing is masking up properly, and perhaps doubling your mask protection - especially while travelling.