How much do face masks protect against coronavirus?

Face coverings have become mandatory in indoor spaces in England as of today, with fines of up to £100 for anyone refusing to comply.

Masks are now compulsory in shops, supermarkets, indoor shopping centres, takeaways, banks and post offices, as well as airports and train stations.

New government guidelines published on Thursday state that coverings, such as cloth masks or bandanas, must be worn at all times when in these spaces.

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The only exceptions are when sitting down to consume food and drink, though masks must remain on when buying food and drink to take away, The Guardian says.

Police have been given powers to enforce the rules and those failing to comply could be handed fines of up to £100, mirroring the rules for failure to wear a mask on public transport.

However, police forces have said they will only be enforcing the rules as a last resort, and officers will not be patrolling premises, reports the BBC.

Exemptions to the rule include children under 11, and those with disabilities or certain health conditions, such as breathing issues or learning difficulties, that make it harder for them to wear a face covering.

Do masks work?

A study published last month found that making face masks compulsory could slow the spread of Covid-19 by as much as 40%.

Researchers studied the impact that face coverings had on regional epidemics in Germany, where some areas made masks mandatory in shops and public transport in April, the Daily Mail says.

They found that the move reduced the number of infections over the next 20 days by almost a quarter, rising to 40% after two months. The scientists behind the study said it provided “strong and convincing statistical support” that masks “strongly reduced the number of incidences” of Covid-19.

Face coverings have been compulsory on public transport in England from 15 June as part of the effort to control the spread of coronavirus. Transport Secretary Grant said that passengers should avoid buying up surgical masks and should wear the kind of face covering that could be made at home.

Do makeshift masks work?

The US Centers for Disease Control and Prevention (CDC) has called for the public to use makeshift cloth coverings. Under the US proposal, health officials are urging the public to leave medical masks, which are in dangerously short supply, for healthcare workers.

Thomas Inglesby, director of the Johns Hopkins Center for Health Security think-tank, was among those in favour of the plan, reports The Washington Post.

“I think it would be a prudent step we can all take to reduce transmission,” Inglesby said. However, he added that DIY face coverings are by no means a perfect solution and should not be used as an excuse to ignore social distancing rules.

The CDC has updated its guidance on strategies for “optimising the supply of face masks” to say that in healthcare settings where such protective gear is no longer available, workers caring for patients with the new coronavirus could use homemade masks, such as bandannas and scarves, as “a last resort”.

But critics of the plan to extend that advice to all US citizens say wearing DIY masks could give people a false sense of security, making them less disciplined about observing social distancing measures.

Another risk is that such masks could become contaminated with the virus, and then not properly cleaned or disposed of.

“Homemade masks theoretically could offer some protection if the materials and fit were optimised, but this is uncertain,” Jeffrey Duchin, a Washington health official, told the Post.

But others argue that the gains outweigh the risks. “Mask-wearing also serves as a reminder to all that we are in a crisis situation and are trying to be good citizens by covering our mouths,” said Harold Varmus, former director of the National Institutes of Health.

However, the World Health Organization (WHO) is continuing to advise that only people who are infected with or caring for someone with the Covid-19 coronavirus should wear masks.

“There is no specific evidence to suggest that the wearing of masks by the mass population has any potential benefit. In fact, there’s some evidence to suggest the opposite in the misuse of wearing a mask properly or fitting it properly,” Dr Mike Ryan, executive director of the WHO health emergencies programme, said at a media briefing in Geneva in March.

Do medical masks work?

Decades of research has found that surgical masks do protect healthcare workers from getting infected in hospitals.

A 2009 study in the Journal of the American Medical Association indicated that even low-end medical grade masks offer protection close to the level of high-end models.

Quartz reports that a CDC study published that same year found that “masks could cut caretakers’ risk of viral infection by 60% to 80%”. However, “less than half of people in the study wore their masks consistently”, highlighting a problem with proper usage, adds the news site.

Another key problem with medical masks is the lack of them during the ongoing pandemic, reports CNN.