The European Union's top health agency this week joined that of the United States in recommending that it may help to beat the coronavirus pandemic if everyone wears a face mask in public.
The European Centre for Disease Prevention and Control was previously cautious on recommending masks, citing fears that people could place themselves at greater risk by wearing masks improperly, or by taking greater fewer precautions due to a false sense of security. There were also concerns of a run on short supplies needed for health workers.
While these reservations remain, the ECDC this week published new advice recommending that the use of masks, including home-made ones, may help to curb the spread of infection.
“The use of face masks in public may serve as a means of source control to reduce the spread of the infection in the community,” says the paper, which is a summary of recommendations based on an assessment of available evidence.
The masks work “by minimising the excretion of respiratory droplets from infected individuals who have not yet developed symptoms or who remain asymptomatic”, it states.
The shift comes as public health authorities in a number of countries including the US have shifted towards recommending masks, overcoming fears about misuse and a shortage of masks with public information campaigns about how to make one at home and use it properly.
So what is the rationale behind the shift?
Coughs and sneezes
Coronavirus is thought to be spread by tiny droplets from the nose and mouth produced by coughs and sneezes, and possibly also by simply talking and breathing. It is often spread by people who do not know they are infected.
The rationale for promoting mask-wearing by the public is that it stops people who have the virus spreading it to others. It’s not about protecting the wearer.
“People who use face masks in the community want to protect their fellow citizens in case they are infected,” says the ECDC in its report on the subject. “Wearing a mask is not an act of selfishness and should be promoted as an act of solidarity.”
As a campaign in the Czech Republic put it: "My mask protects you, your mask protects me."
Not all masks are the same. Respirators like N95 and FFP2 masks are used for the protection of health workers who are working with coronavirus patients, and are in short supply.
The more standard surgical masks act as a simpler barrier, primarily stopping particles from the wearer’s nose and mouth from reaching the patient.
Making masks at home avoids depleting supplies needed for healthcare workers.
According to a study cited by the ECDC, there is evidence that homemade masks can be as effective as some models of simple surgical masks if used right. The ECDC does not have recommendations on how to best make a mask. But the US Centres for Disease Control and Prevention advises three easy ways on its website: with a bandana, by cutting up a T-shirt or by sewing one from cotton. It advises that masks should fit closely to the face, and have multiple layers of fabric.
Infectious droplets
The ECDC suggests wearing masks in busy enclosed spaces, such as public transport, shopping centres and grocery stores. It notes this might be particularly important for people who work in jobs that require being close to others, such as cashiers or members of the police.
The ECDC stresses that, in order to work, masks must completely cover the nose and mouth. It’s important to wash your hands before putting them on and after removing them, and not to touch the outside of the mask where infectious droplets could have landed.
They should be washed regularly at 60 degrees, with normal detergent.
Its advice emphasises that masks complement – but do not substitute for – frequent hand-washing, physical distancing, staying at home when ill, working remotely if possible, protecting others from your coughs or sneezes, and avoiding touching the face. It’s important to keep doing those things.
But if enough people take up the practice and do it properly, authorities hope that mask-wearing could offer a ray of hope on how to ease out of lockdown.
Taiwan, Hong Kong and South Korea never locked down public life. But they still managed to curb the spread of the virus. They identified and isolated cases with rigorous testing and contact-tracing. And mask-wearing in those places is near-universal.