Are two masks better than one? The rise of ‘double masking’

Forget Kamala Harris in ecclesiastical purple or poet Amanda Gorman’s cherry-red hairband - the look everyone was talking about after Joe Biden’s inauguration last month was the “double mask”.

From the newly minted president himself right down to his security detail, everyone seemed to have got the memo that two masks are better than one.

Now, the double mask has won the scientific stamp of approval from the US Centers of Disease Control and Prevention which has published a study showing that transmission of the virus can be reduced by up to 96.5 per cent if both an infected and uninfected person wear a tightly fitting face covering.

The study compared wearing no mask, a poorly fitted surgical mask, a cloth-only mask and a double mask in a simulation of the spread of respiratory drops between an infected and uninfected person.

The research concluded that the best way to stop the spread is to wear a cloth mask on top of a surgical mask or to wear a surgical mask on its own but tie the straps where they meet the mask to ensure there are no gaps. Although this approach might not work for men with beards as they can interfere with the fit of masks, or for children, whose faces are smaller, the study warned.

But Dr John Brooks, lead author of the study, said: “Any mask is better than none. There are substantial and compelling data that wearing a mask reduces spread, and in communities that adopt mask wearing, new infections go down.”

The double mask debate

Trish Greenhalgh, professor of primary care at Oxford University and a proponent of mask wearing long before it became de rigeur, said the double mask debate boils down to this: one mask protects you, two masks protect me.

“If I’m asking ‘should I wear a mask to protect you?’, one mask is OK because even a badly-fitting reasonably thick one-layer mask - for example, made of denim - is pretty effective at blocking the droplets that come out of my mouth when I breathe or speak.

“But if my question is ‘should I wear a mask to protect me?’, the answer is I will need more than that badly-fitting one-layer,” she said.

This is because if there is just one person in the room who is not wearing a mask the virus can become aerosolised - carried in tiny droplets - and spread throughout the space.

“To protect yourself against that, you need to have a really tight seal around your mouth and nose, and the mask needs to be a more effective filter because aerosolised virus is harder to stop than virus in large droplets,” she said.

What the experts say

In wake of a recent study that found that the Oxford-AstraZeneca vaccine may be only 10 per cent effective against the South African strain of coronavirus, a member of New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG) advised layering up face coverings is the “safest way to proceed” against the new variant.

However, double-masking isn’t an entirely new idea. In January, Dr Anthony Fauci, chief medical advisor to US president Joe Biden, said wearing two masks or face coverings at the same time is “common sense” and may offer a higher level of protection against Covid as the world deals with the emergence of new strains. “If you have a physical covering with one layer, you put another layer on, it just makes common sense that it likely would be more effective,” he said.

Indeed the idea has already taken off in the US: Biden, vice-president Kamala Harris and the US national youth poet laureate Amanda Gorman – were among those spotted with double masks at the inauguration. Pete Buttigieg, the newly appointed Secretary of Transportation and former presidential candidate, was also seen double-masking, wearing a high-quality medical grade mask underneath a black fabric one.

The concept is relatively straightforward: simply layer one on top of the other, ideally a cloth mask on top of a surgical mask. The former “provides an additional layer of filtration” and improves the fit, and the latter “acts as a filter", according to experts outlined in the science journal Cell. Together, the masks offer the public “maximum protection.”

In the UK

The trend, however, hasn’t yet taken off in the same way in the UK, but will it? It’s true there is a growing body of evidence which suggests that face masks are effective at preventing coronavirus transmission; one Canadian study found covering the face indoors resulted in up to 46 per cent fewer new cases.

Dr Shaun Fitzgerald, Director of the Centre for Climate Repair at Cambridge, says that there are other factors which must be considered when double-masking. He says that people need to remember that wearing face masks is mainly about stopping the spread of infection rather than protecting the wearer from catching the virus. While donning two masks can help give the wearer an element of control, it also still leaves their eyes exposed – which studies have shown can be another possible point of transmission.

There are practical elements to consider, too. As Fitzgerald sees it, wearing two masks might mean you are more inclined to adjust them, or touch your face more frequently, which could negate the benefits of wearing a covering in the first place. He maintains that the best way to protect yourself and others from Covid is to avoid mixing with other households.

Once we are out of lockdown, he adds that “hands, face, space, and air” are going to be the four most important factors in keeping transmission rates of the new strain down. “Ensuring you are in an adequately ventilated environment, is important and especially so in winter when there may be a temptation to close all the windows completely. We mustn’t – we should crack open the high level windows to keep the air reasonably fresh,” he says.