9 questions about coronavirus and masks, answered

Should you wear a mask? How do you make one? What’s the evidence? Here are some answers.

After months of muddled messaging from different factions of the public health world, the Centers for Disease Control and Prevention released straightforward guidance in the middle of the coronavirus pandemic: Everyone in the US should wear a cloth mask or face covering while in certain public settings.

The recommendation marks a shift from the federal government. Less than six weeks ago, Surgeon General Jerome Adams tweeted that members of the general public should “STOP BUYING MASKS!” He added that masks “are NOT effective in preventing general public from catching #Coronavirus, but if healthcare providers can’t get them to care for sick patients, it puts them and our communities at risk!”

The CDC is still advising against the general public wearing traditional medical masks, such as surgical variants and N95 respirators, to preserve them for health care workers. The shift in messaging on cloth masks, the agency said, came in light of evidence that people with few or no symptoms of Covid-19 can still transmit the virus.

The upshot: Masks can help stop the spread of coronavirus not just by protecting the wearer, but by preventing the wearer — who could be an asymptomatic spreader — from breathing and spitting their germs everywhere. Some studies in households and colleges “show a benefit of masks,” Raina MacIntyre, head of the Biosecurity Research Program at the University of New South Wales in Sydney, Australia, told me, “so it would be plausible that they would also protect in lower-intensity transmission settings such as in the general community.”

But masks do not make you invincible. They can’t replace good hygiene — Wash your hands! Don’t touch your face! — and social distancing, both of which have been key to stemming the coronavirus even in Asian countries where widespread mask use was already common. Epidemiological models also suggest coronavirus cases will rise if social distancing measures are relaxed, potentially causing hundreds of thousands, if not millions, of deaths in the US alone. That’s true whether people are gathering wearing masks or not.

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Still, the CDC’s about-face has left many people with plenty of questions: What does it mean to use a mask correctly? When should they be used and washed? Do you need them for all public situations? Can they really keep you safe? If you can’t find a mask, how can you make one?

And why aren’t there more medical masks to begin with?

Here’s a guide to some of the most common questions.

1) When should I wear a mask?

According to the CDC, you should wear a mask in public, particularly while in “settings where other social distancing measures are difficult to maintain (e.g., grocery stores and pharmacies)” and “especially in areas of significant community-based transmission.”

Think of circumstances where it’s going to be harder to keep at least 6 feet away from other people, especially in closed, poorly ventilated places. It’s in those kinds of situations that coronavirus-containing droplets are more likely to spread by air or surfaces.

There are some exceptions to the mask guidance, the CDC stated: “Cloth face coverings should not be placed on young children under age 2, anyone who has trouble breathing, or is unconscious, incapacitated or otherwise unable to remove the mask without assistance.”

And be warned: If you use a mask incorrectly, or start acting recklessly because you’re wearing a mask, it could actually hurt you more than it helps.

If you fidget with your mask, and especially if you touch your face in the process, you can infect yourself with virus-containing droplets your mask caught. If you reuse a mask without cleaning it, you can breathe in or otherwise expose yourself to droplets the mask captured last time. If you generally ease up on good hygiene or social distancing because you’re wearing a mask, you’re putting yourself — and your community — at greater risk.

The CDC offers some tips for how to properly use a mask. Above all, don’t touch the mask and then touch other parts of your face, especially your eyes, mouth, and nose. The entire point of this fabric is to shield you from outside germs. So you don’t want to touch the part of the mask doing the shielding and then the parts of your face that are vulnerable to infection.

You should also wash your hands before and after taking off a mask — before to avoid getting anything on your face and mask, and after to get rid of anything that was on your mask. Remove the mask with the loops, not by touching the front. If possible, throw away disposable masks after using them. And if you can’t throw a mask away, make sure to thoroughly disinfect it with ultraviolet light sterilizers — not something most people have around — or, if using a cloth product, throw it in the wash or clean it with soap and water.

For some people, it might make sense to have multiple masks around if you have to go out multiple times on a particular day. The important thing, though, is to throw a recently used mask in the laundry or in the wash as soon as possible and avoid touching it at all until it’s clean. Do not keep dirty masks around your house, where people can easily touch them and potentially infect themselves.

2) What kind of mask should I use?

The CDC recommends a cloth mask or face covering, whether a professionally made mask or a homemade variant.

The CDC explicitly advises against the general public using a surgical mask, which is the standard mask you’ve probably seen doctors and nurses wear. It also advises against the public using N95 respirators, which are more complex, expensive masks meant to fit more tightly on the face.

Surgical masks and N95 respirators, the agency noted, “are critical supplies that must continue to be reserved for healthcare workers and other medical first responders, as recommended by current CDC guidance.”

Giles Clarke/Getty Images

As it stands, there is a serious shortage of PPE, including masks, for health care workers. There are reports of doctors, nurses, and other health care workers using bandanas and scarves for masks and trash bags for gowns. Hospitals are considering do-not-resuscitate orders for dying Covid-19 patients out of fear that such intensive, close-up procedures could get doctors and nurses without PPE infected with the virus. The CDC, acknowledging the shortage, previously recommended homemade masks for health care workers when no other options are available.

“I am worried that telling people to wear masks will strain already weak supplies that are needed by doctors and nurses,” Jennifer Nuzzo, an epidemiologist at Johns Hopkins University, told me. “If we are able to fix that supply chain, I’d feel less worried about this. But some of the shortages initially were due to members of public and medical staff raiding medical offices’ and hospitals’ supplies for home use.”

Private companies and public officials are racing to fix the PPE shortage. But until it’s fixed, it’s critical that the existing supplies of surgical masks and N95 respirators are left for health care workers who are literally saving people from this pandemic.

3) Will a mask protect me from getting Covid-19?

The CDC’s guidance — and the best argument for wearing a mask, according to the experts I spoke with — is primarily to stop the wearer from infecting other people. That’s especially important for Covid-19, since at least some spread happens when people are asymptomatic, when they have few symptoms, or before they develop symptoms. Universal mask use could stop these asymptomatic carriers, many of whom might not even know they’re sick, from inadvertently infecting other people.

Masks also can offer some protection from others by putting a physical barrier between them and your mouth and nose. But we don’t know how much, because it’s unclear how much the virus spreads through airborne droplets or aerosols.

Masks can’t replace all the other approaches needed to fight the coronavirus, like washing your hands, not touching your face, and social distancing. Still, when paired with all these other tactics — and when used correctly — masks offer an extra layer of protection.

The quality of the research on this topic is weak, with a lot of small, underpowered studies. But the studies that do exist generally favor more people wearing masks.

A 2008 systematic review, published in BMJ, found medical masks halted the spread of respiratory viruses from likely infected patients. In particular, studies on the 2003 outbreak of SARS — a cousin to the coronavirus that causes Covid-19 — found that masks alone were 68 percent effective at preventing the virus. By comparison, washing hands more than 10 times a day was 55 percent effective. A combination of measures such as hand-washing, masks, gloves, and gowns was 91 percent effective.

A 2015 review, also published in BMJ, looked at mask use among people in community settings, specifically households and colleges. Some studies produced unclear results, but the findings overall indicated that wearing a mask protected people from infections compared to not wearing a mask, especially when paired with hand-washing. A big issue was adherence; people were often bad at actually wearing masks, which, unsurprisingly, diminished their effectiveness. But if masks were used early and consistently, the authors concluded, they seemed to work.

A more recent study published in Nature Medicine found that surgical masks appear to block droplets and aerosols containing some viruses, including the flu and coronavirus.

Other studies have produced similar results, typically finding at least some protective value from masks as long as they’re used consistently and properly.

The results vary depending on the mask. N95 respirators are, in theory, the best possible masks. But they require a bit of skill and fitting to use — to the point that a 2016 review in CMAJ couldn’t find a difference among health care workers using N95 respirators versus surgical masks for respiratory infection, likely due to poor fitting. That’s another reason these masks should be reserved for the professionals.

Cloth masks, meanwhile, are much less effective than surgical masks or N95 respirators, as a 2015 study in BMJ found. And they can be extra risky, since they can trap and hold virus-containing droplets that wearers can then breathe in. But they still, in general, offer more protection than no mask at all, several studies concluded.

There’s no good research on how wearing a mask could affect people’s behaviors, but the experience of some Asian countries suggests it’s possible to adopt social distancing, good hygiene, and masks in the midst of an outbreak. Taiwan and South Korea, for example, have done a better job containing Covid-19 than the US while embracing masks and all the other evidence-based measures.

To emphasize: Yes, masks can help. But they’re not an excuse to ease up on social distancing, good hygiene, and all the other things public health officials are recommending right now. Do all of those things too.

4) Do I need a mask if I’m walking or running in the open air?

Probably not — but if used properly, wearing a mask probably can’t hurt, and might help encourage others to wear one too.

The CDC specifies that it’s recommending cloth face coverings where social distancing isn’t possible. A solitary walk or run outside is typically not going to fall into one of those categories.

In general, masks become more helpful as the risk of infection increases. If you’re having closer, more prolonged contact with potentially sick people, using a mask is more likely to protect you. And if you’re potentially sick and having closer, more prolonged contact with others, a mask is more likely to protect them from your germs as well.

“Are people having those prolonged, close-contact interactions with people?” Saskia Popescu, an epidemiologist focused on hospital preparedness, told me. “Because that’s what’s more considered high-risk. … It’s that face-to-face for a significant chunk of time.”

That’s why the CDC had already recommended masks for people who know they’re sick or interacting with someone who’s sick. People who frequently interact with others as part of their jobs, like a first responder or a grocery store clerk, are more likely to get good use out of masks too. That especially includes health care workers, who spend more time with sick people than anyone else — which is why they need masks and other PPE more.

Certain populations also may want to especially consider masks in less risky environments, such as people who are older or have underlying health issues, like a compromised immune system, that put them at greater risk if they’re infected.

Besides the health benefits, there’s also a potential social value to wearing a mask everywhere: It could push more people to do so as well. If more people are out in public wearing face coverings, that could help remove the stigma that only sick people wear masks. So if you go out with a mask in more situations, it could not only help you and those around you, but it might help instill a healthier norm for the rest of society too.

5) How do I make a mask?

There are a lot of options! But keep in mind guidance, from the CDC, about a proper mask: It should fit snugly but comfortably around the face, be secured around the ears with ties or loops, include multiple layers of fabric, allow for breathing without restriction, and be readily washable without damage.

If you have the time and can sew, the CDC recommends a face covering that can be made with two 10-inch by 6-inch rectangles of cotton fabric, two 6-inch pieces of elastic or rubber bands, string, cloth strips, or hair ties, a needle and thread or bobby pin, scissors, and a sewing machine. Here’s the agency’s four-step tutorial:

Centers for Disease Control and Prevention

There are also some alternatives on YouTube. Here is a good one:

If you’re like me and the idea of sewing anything sounds like a total nightmare, the CDC offers a non-sewing option. It just requires a T-shirt and a pair of scissors. Here’s the three-step tutorial:

Centers for Disease Control and Prevention

If you’re even more like me and that mask is still too much, the surgeon general posted a 45-second video guide on Twitter for an even easier mask that can be made solely with a T-shirt or just about any other cloth fabric and two rubber bands:

Chances are the less skill-intensive, less time-consuming masks will be, at the very least, less comfortable, and maybe harder to wear for long. But if you’re in a pinch, or if you’re unable to do more complicated tailoring, the easier alternatives offer more protection than nothing.

6) Why aren’t more medical masks available?

The simple answer is that supply hasn’t kept up with demand. Prior to the coronavirus outbreak, China made half the world’s face masks. When the outbreak took off there, China started to use its supply and hoard what remained. This problem has only spread since, as more and more countries hoard whatever medical supplies they can get — with some, like Germany, even banning most PPE exports. So as demand increased due to Covid-19 — not just from health care workers but from a general public increasingly scared of infection — there was less supply to go around.

On a deeper level, though, the shortage in masks and other PPE reflects America’s — and, really, the rest of the world’s — poor preparedness for a pandemic. The mask and broader PPE shortage, in fact, was well-known to the US government before the Covid-19 outbreak, yet the US did not prepare.

“When we have done exercises in the past for pandemic preparedness, supply chain issues were a well-documented challenge,” Popescu said. “This is something we’ve known about — maybe not to this extent, but this isn’t a shocker. It’s more surprising that we let it get this bad.”

Giles Clarke/Getty Images

Mario Tama/Getty Images

One of those simulations held by the federal government, as the New York Times reported, covered a pandemic that looked a lot like the one we’re facing now: a respiratory virus that started in China and made its way to the US and the rest of the world.

Among the many problems, the Times found, were “deficiencies ‘in personal protective equipment use.’” The exercise found that the US didn’t have the means to quickly produce more PPE. When states turned to the federal government for help in the exercise, there was “confusion” and “bureaucratic chaos” as requests and submissions hit multiple agencies at once.

This was far from the only simulation to produce these results, experts told me. Jeremy Konyndyk, senior policy fellow at the Center for Global Development, argued a previous outbreak should have acted as a warning for the world: the 2014-2016 Ebola outbreak. While working in President Barack Obama’s administration at the time, Konyndyk quickly realized that the US — and much of the world — was simply not ready for a major disease outbreak.

“I came away from that experience just completely horrified at how unready we would be for something more dangerous than Ebola,” he said, noting Ebola was, thankfully, relatively hard to transmit.

Indeed, experts and advocates argue that the US generally underfunds disease outbreak preparedness and public health programs more broadly. It’s these concerns that led the Obama administration, after the Ebola outbreak, to attempt to scale up preparedness by establishing a White House office dedicated solely to the issue and producing a 69-page playbook in case of an outbreak. But President Donald Trump’s administration neglected and rolled back these efforts, eventually disbanding the White House office.

We’ve seen the results in the botched rollout of coronavirus testing, but PPE offers another example. America could have shored up its supplies of PPE in its strategic stockpile. It could have ensured that there would be surge capacity to boost production in case of emergency. And it should have been doing this all before the coronavirus pandemic.

But it didn’t, even after it became clearer, around January and February, that the coronavirus was a looming threat. By early March, federal officials acknowledged the Strategic National Stockpile had just 1 percent of the medical masks the country needed in a full-blown pandemic.

“The US … was not prepared,” Jen Kates, director of global health and HIV policy at the Kaiser Family Foundation, told me. “A good preparedness plan would have helped address this and had things in place to allow for that increased need to be met.”

So the US is playing catch-up with different public and private interventions to boost PPE production. Until that’s fixed, we simply don’t have enough medical masks to go around.

7) If medical masks are better, why shouldn’t I get some for myself?

Because health care workers need them more, since they’re constantly in contact with those who are sick — in a way not many other people, if any, in the general public are. And even if you take a totally selfish perspective on this, there are good reasons to want health care workers to get these medical masks first.

As coronavirus has spread, experts have talked up “flattening the curve.” The idea is to spread out the number of coronavirus cases — through social distancing, testing, contact tracing, and other protective measures — to avoid overwhelming the health care system. Here’s what that looks like in chart form:

Christina Animashaun/Vox

The PPE shortage could make it harder to flatten the curve of new cases if doctors and nurses get sick. But the line representing health care system capacity also isn’t a constant. If we develop more capacity, it can handle more cases at once. If capacity falls — if doctors and nurses get sick because of a lack of protective equipment, or refuse to work without conditions that can ensure their safety — even a flatter curve will be hard for the system to handle.

That’s why experts, even those who acknowledge that the public would benefit from using masks, say that doctors and nurses should get priority: This isn’t just about keeping people on the front lines safe; it’s about keeping all of us safe.

To put it in selfish terms: If you do get sick with the coronavirus or anything else during this pandemic, and you want to make sure that there are doctors and nurses available to treat you, you should let them get the masks they need first.

It’s true that we might all be better off wearing surgical masks in an ideal world. But that’s not the world we live in right now. For all our sakes, we should act accordingly.

8) If masks are so great, why is the CDC just telling us this now?

Officially, the CDC has said it changed its stance with the changing evidence. As it became clearer that asymptomatic transmission was happening with the coronavirus, the CDC argued, the benefits of everyone wearing a mask increased, since they could help stop transmission from people who don’t even know they’re sick.

Unofficially, the answer is a little more complicated. In my discussions with public health officials and experts before the CDC changed its guidance, it seemed many people were afraid of saying anything that could exacerbate the PPE shortage for health care workers or get members of the general public to think — incorrectly — that they could ease social distancing measures if they just wear a mask.

“I fear that if we tell everyone they should go out and buy masks, it will not only contribute to the PPE shortage,” Jaimie Meyer, an infectious disease expert at Yale University, told me, “but it will give a false sense of a ‘quick fix’ for protection, whereas people still need to be practicing social distancing strategies that are much more effective, though perhaps socially, psychologically, [and] logistically challenging.”

Part of the issue is the CDC also operates on a different evidence level than a lot of the public. The agency tends to follow the best reviews of the scientific evidence with very rigorous standards for what’s a good study and what’s not. So what may sound like good enough evidence and reasoning to you and me may not be good enough for the CDC. Since the scientific evidence for public mask use isn’t great — even if it’s generally positive — the CDC, as an agency filled with scientists, was just more skeptical of taking a leap than many laypeople were.

Regardless of the reasoning, the CDC’s messaging backfired. As health care workers clamored for masks, it became increasingly harder to tell the public that masks wouldn’t benefit everyone else. By obfuscating and failing to fully explain the issue, officials likely sowed distrust toward their guidance. And the public rushed to buy masks anyway.

9) How can I donate masks to health care workers?

The dire shortage of masks and other PPE has led to several options for donations:

• If you want to make and donate cloth masks, WeNeedMasks.org provides options for most states and Puerto Rico.
• If you have surgical masks, N95 respirators, and other PPE around, #GetUsPPE is another option. (Although note that many places will only take unopened supplies.)
• If you’re a manufacturer or supplier, the N95 Project is trying to connect companies that make or have masks with the hospitals and clinics that need them.

At this point in the pandemic, health care workers and facilities all over the country will gladly accept the help they can take. Some places, like New York and Louisiana, are dealing with much worse coronavirus outbreaks right now and really need the supplies today.

Steve Pfost/Newsday via Getty Images

But it’s also worth being realistic about just how far donations can go. Given the research, cloth masks are simply not suitable replacements for actual medical masks. With medical masks, N95 respirators are widely regarded as more effective than conventional surgical masks when properly fitted.

So even with donations, it’s on the federal government to set up more production and coordination of supply lines to make sure places in need get PPE. It’s on private producers to step up and do what they can. (Some car, clothing, and pillow companies, among others, have already done so.)

And it’s on us — to make sure that the existing supplies of masks and other PPE are made available to health care workers. Americans can accomplish that, in part, with donations, but we can also do that by not buying surgical masks or N95 respirators until the shortage is fixed, and instead relying on cloth and homemade coverings.

So, yes, health experts recommend wearing a mask in public. Just don’t take one from health care workers. And keep doing all the other things public health officials recommend, like social distancing and washing your hands, as we deal with this pandemic.