Based in Geneva, Dr Walraven has direct management responsibility for the Aga Khan Health Service Companies, located in South and Central Asia, East Africa, and the Middle East. In this interview, he explains the value and importance of wearing a face mask in our continued fight against Covid-19.

How can face masks make a difference in our fight against Covid-19? How do masks protect wearers or the people around them?

In our response to Covid-19 we need to follow the evidence, and when it comes to wearing face masks, we have much better evidence today than four to five months ago that it plays an important role in the prevention of transmission of the infection. 

We now know that wearing a mask might not protect someone from contracting Covid-19, but it can prevent you from infecting others. People often think that because they feel fine and don’t have symptoms, they don’t have to wear a mask. But the reality is that at least one in six people infected with Covid-19 do not show symptoms. This means that even when you look and feel healthy, you may have come in contact with the virus that causes the Covid-19 disease and may, in fact, be a carrier, passing the virus to anyone who comes into contact with you during its incubation period. Wearing a mask can prevent transmission of the infection. Here’s how:

Masks lower the risk of people infected with Covid-19 from spreading the virus through the saliva and mucous droplets they expel into the air when they speak, cough, or sneeze. These droplets often evaporate into tiny particles that can linger in the air and infect others. By wearing a mask, a person who is infected can trap their droplets into a face covering before they can evaporate and become contagious for others. 

When combined with frequent hand washing, physical distancing (keeping at least 1.5 meters between you and others) and limiting how much you touch your face, wearing a mask can lower the spread of Covid-19. Simply put, it’s the responsible thing that each and every one of us can and should do because masks are only effective if they are worn by all people in public settings. 

What are the types of face coverings and why does it matter? Which types are best?

The World Health Organization guidance is that for the average person who is not working with patients in a healthcare setting, a cloth face mask is best. But it’s important that we understand the differences between the various masks that are being used in most countries around the world. 

  • N95 respirators (or professional-grade medical masks): These masks are medical devices that are used by healthcare professionals and first responders (like firefighters, police officers, emergency room personnel, and ambulance staff) to protect themselves from exposure. The individuals who wear these masks have to get them fitted to ensure they are using the right make, model, and size to form a tight seal between the air outside the mask and their face. N95 respirators are currently in short supply around the world, especially in developing countries and should be reserved for the use of healthcare professionals and first responders only. 
  • Surgical masks: These masks are disposable paper masks that cover the mouth and nose. These are the masks you often see doctors and nurses wearing during surgeries and other medical procedures. Although they do not fit tightly on the face, they are fluid resistant and provide some protection against larger respiratory droplets from coughs and sneezes. Unlike cloth face masks, surgical masks cannot be washed and must be discarded after each use. 
  • Cloth masks: These masks are made from multiple layers of fabric to create a barrier between your nose and mouth, and the outside air. They hold back any respiratory droplets that you may breathe, cough or sneeze out. It’s important to remember, however, that the thicker the mask, the greater the barrier. The great thing about cloth masks is that you can make them yourself using fabrics from your home. To learn how you can make your own mask, take a look at this guide developed by the Centers of Disease Control and Prevention.
  • Face shields: These are clear sheets of plastic that are attached to a headband to cover your face from the top of the head to the bottom of the chin. If you are able to maintain a physical distance of at least 1.5 meters from others when in public and if you are wearing a mask, you do not need a face shield. Face shields should never be worn alone as they do not provide the same protection as a mask because they do not offer a barrier against respiratory droplets, which can still come up from under the plastic sheet.

How should one wear a mask?

Select a mask that covers your mouth, nose, and chin completely, and that can be secured tightly. Make sure the mask is clean before you put it on. If the mask is wet or damaged in any way, do not use it. Do not use disposable masks more than once.

Before you touch your mask, make sure you wash your hands with soap and water thoroughly. If your mask has ear loops, hold the mask using the ear loops and place a loop around each ear. If your mask has ties, bring the mask in level with your nose and securely tie the straps around your head and neck. Pull the bottom of the mask over your mouth and chin, and make sure there are no gaps on the sides. 

It is important to not touch the front of your mask as you’re putting it on and taking it off as this area may have trapped germs, bacteria, and viruses that can be transferred to your hands. 

Once you remove the mask, wash your hands with soap and water thoroughly. Do not share masks with your friends or family.

How should one remove their mask safely?

Just like when you put on your mask, start by washing your hands with soap and water. If your mask has ear loops, hold both the ear loops to gently lift the mask away from your face to remove it. If your mask has ties, untie the bottom strap first followed by the top strap. Using the straps, release the mask from your face. Do not touch the front of the mask as it may be contaminated. 

If you’re using a disposable mask, throw it away in a covered wastebasket. If you’re using a homemade face mask, store it in a clean, sealed plastic bag. Only do this if it is not dirty or wet, and if you plan to reuse it. Be careful not to touch your eyes, nose, or mouth when removing your mask. 

Remember that homemade masks must be washed regularly to be effective. Wash the mask with soap or detergent using hot water (if available) at least once a day. 

Are there specific people who should or should not wear a mask? 

The answer to this question is simple: Each and every one of us should wear a mask, every time we leave our homes, and when it is not possible to maintain a physical distance of at least 1.5 meters from others. 

The only exceptions to this recommendation are people that have a respiratory condition (like asthma) where wearing a mask could pose a greater health risk than benefit, or those who have suffered a trauma and find it distressing to wear a mask. Masks should also not be worn by children under the age of two or by people who are unconscious, incapacitated, or otherwise unable to remove their mask on their own.

Why do we need to keep masks on during communal prayer?

It is important that each of us wear a face mask when we are in a public setting where we could be exposed to a large group of people, and especially in an indoor, closed area. 

While community prayer halls have made provisions to safeguard against transmission by enforcing physical distancing measures, and making hand sanitisers, as well as soap and water available to members, in reality it is not always possible to keep at least 1.5 meters away from others. In these instances, wearing a face mask can reduce the risk of one person infecting others in the community with Covid-19.

For additional information about face masks, please log on to the AKDN Covid-19 Digital Resource Library. Here you’ll find information about how to make a cloth mask, as well as clear guidance on when, where, and how to wear it.


Dr Walraven joined the Aga Khan Development Network in 2003. Before this he worked for a period of 15 years in Africa in healthcare provision, management and research, with a major emphasis on district health systems. Gijs Walraven has published more than 120 papers in international peer-reviewed journals. He is also the author of Health and Poverty: Global health problems and solutions (Routledge, London), which received first prize in the category 'health and social care' in the 2011 British Medical Association Annual Book Awards.