Can a Face Mask Prevent Coronavirus? An Expert Weighs In

As the coronavirus spreads across the globe, face masks are beginning to sell out. But are they actually effective? Should we buy them before they’re gone? An expert weighs in.

Since early January when the coronavirus was identified in Wuhan, China, we’ve been updated constantly on how and where it’s spreading. So far, the virus has killed over 420 people globally, infected over 17,000 in China, and been reported in 170 cases in 20 countries, including Canada.

Like SARS or the common cold, coronavirus is a respiratory infection, which affects the nose, throat, and lungs. It’s spread mainly by way of sneezing, coughing, and exhalation from those infected, as well as personal contact like shaking hands with those infected, which explains why it’s able to travel so far and so quickly.

The coronavirus has caused some people to panic, and understandably so. Health Canada has deemed the public health risk of the coronavirus as being low for Canadians, but there are still precautions that need to be taken to prevent the virus from spreading. Should we avoid certain places? Should we wear face masks in public spaces? What about gloves?

We reached out to Dr. Andrea K. Boggild, a medical director at the Tropical Disease Unit in Toronto General Hospital and associate professor of medicine at University of Toronto, to have our questions about coronavirus answered.

According to, “coronaviruses are spread mainly from person to person through close contact.” What qualifies as “close contact”?

Close contact refers to things like touching and shaking hands and being in close proximity (within a few feet) to those with infection. The infection can spread from person-to-person by breathing in viruses that are coughed or sneezed into the air, or onto hands that then touch other hands or faces. Thus, it is extremely important to practice frequent hand washing in order to reduce the likelihood that virus particles on our hands end up in our eyes, nose, or mouth, which can establish infection.

What can we do to prevent contracting coronavirus?

1. Wash hands frequently

The best way to protect oneself from infections—especially respiratory viruses of any kind, which include coronavirus—is to practice good hand hygiene. This means frequent hand washing with soap and water or use of an alcohol-based hand rub or sanitizer. Hand washing is particularly important before touching mucous membranes such as the mouth, nose, and eyes.

2. Prevent the spread of germs

If people need to cough or sneeze, these should be directed into the elbow or a tissue as a covered cough or sneeze will reduce the number of virus particles that are released into the air. Wiping down frequently touched surfaces in the home (such as door knobs) with standard household cleaner is also a good idea.

3. Ensure your vaccinations are up to date

Since we are right in the middle of our annual respiratory virus season, everyone should speak to their doctor or pharmacist about being immunized against influenza. Now is also a good time to speak to your doctor about updating all of the respiratory tract infection vaccines for which you may be eligible, depending on your age and health status. This includes vaccines for infections like pneumococcal pneumonia and pertussis (Whooping cough).

4. Travel smart

When traveling anywhere, Canadians should avoid sick people where possible, and all animal markets. Travellers should avoid eating raw or undercooked animal products. Frequent hand washing during travel is also important, particularly if visiting crowded areas. It is also a good idea for Canadians to have a pre-travel medical consultation before going on a trip as this presents an opportunity to update routine immunizations and receive any that are recommended or required for the trip.

Should we be wearing a face mask to keep ourselves safe from the coronavirus?

Authorities are not recommending the use of face masks for the general public. At this point, only very limited person-to-person transmission has occurred among close contacts outside of China, and the virus is not spreading in the community here or in most countries with cases outside of China. So, wearing a mask out in public in order to protect oneself against coronavirus is unlikely to be helpful.

On the other hand, by the very nature of the job, healthcare workers are exposed to higher concentrations of respiratory viruses in much closer proximity to sick patients than are members of the public. Thus, our public health and infection prevention and control authorities recommend that healthcare workers caring for patients with any type of respiratory tract infection use masks—either surgical or N95 depending on the likely infection—in order to reduce transmission of these viruses within healthcare facilities. However, wearing a mask around in public at this time is not based on the best available scientific evidence, nor is such practice recommended by local public health authorities, the Public Health Agency of Canada, or the United States Centers for Disease Control and Prevention (CDC).

How effective are face masks at preventing diseases anyway?

Compared to N95 respirators, surgical masks are more loose fitting and provide a barrier to catch fluid droplets from the person wearing the mask. Because they are loose fitting, they do not provide an absolute barrier to viruses that are acquired by inhalation. On the other hand, when worn correctly, N95 respirators are tight-fitting and filter out 95% of minute particles, including viral particles, that are in the air. These respirators need to be properly fitted by a professional “fit-tester” in order to function correctly. As such, N95 masks are only used by healthcare workers when they might be encountering a very high load of virus particles in the air, such as when caring for a patient who might be coughing or sneezing in close proximity to the healthcare worker.

People who are sick with a respiratory tract infection that is severe enough to warrant medical attention, rather than just home self-isolation, should wear a mask en-route to the healthcare facility, such as a family doctor’s office or the hospital. If those with a respiratory tract infection needing medical attention have travelled to China in the past 2 weeks, or live with family who have travelled and are sick, then it is also a good idea to telephone ahead to the healthcare facility or doctor’s office to inform them of the situation before arriving.

How worried should we be about the coronavirus?

The Public Health Agency of Canada has determined that the public health risk to Canadians and Canadian travellers from 2019-nCoV is low at this time. Canadians should not be overly concerned at this point and should go about their regular activities as they would during any seasonal influenza season, which includes getting a flu shot and washing hands frequently.

If people happen to catch a cold or the flu, they should remain off work or school until better so as not to spread these germs to others.

Canadians are advised to avoid all non-essential travel to China right now, and all travel to the Hubei province of China.

Want to learn more? Here are a few helpful resources for Canadians:

Follow Dr. Andrea K. Boggild on Twitter @BoggildLab.