Wearing a face mask — regardless of how flimsy or tight-fitting it is — is better than social distancing at preventing you from catching Covid, a study suggests.
Researchers found that donning a covering could lower the risk by up to 225 times, compared to solely relying on a three-metre rule.
Masks have been mandated in almost every country in the world at some point in the pandemic but the jury’s still out on their efficacy due to contradictory evidence.
The latest research, by a team of German and US experts, is the latest to conclude that wearing a face covering offers ‘enormously high’ protection.
It found a 90 per cent chance of catching Covid if you stand across from an infected person for five minutes and neither of you wear a mask, even with a gap of 3metres.
Whereas it would take 30 minutes for the risk to be that high if someone was to wear a surgical mask, even if it doesn’t fit ‘perfectly’ on the face.
In the most ideal scenario, where both people wear a medical-grade FFP2 mask and are kept apart, the chance of transmission is just 0.4 per cent after an hour.
Experts from the universities of Göttingen and Cornell who did the study said their finding ‘makes social distancing less important’.
It comes after a major review found that widespread mask use could cut infection rates by 50 per cent, double the amount from solely social distancing.
Masks were last week made compulsory in England again on public transport and in shops in response to the ultra-infectious Omicron variant.
German and US researchers found donning a covering could lower the risk of catching Covid by up to 225 times, compared to solely relying on a three-metre rule. Their graphic shows the risk of Covid infection depending on one of three different types of mask being worn (top left of graph) by an infected person and non-infected person. The three mask options are an FFP2 mask with an adjustment, without an adjustment and a surgical mask. FFP2 masks are thicker and fit more snuggly around the nose and mouth compared to surgical masks. Each face plotted on the graph shows what mask the infected person was wearing (on the left, marked with an ‘i’) and what mask the non-infected person was wearing (on the right, marked with an ‘s’). If both people wear an FFP2 mask with an adjustment (bottom left of graph, marked with FF), there is just a 0.14 per cent risk the non-infected person will catch the virus. The risk rises to 0.64 per cent (second face on graph) if the non-infected person’s FFP2 mask cannot be adjusted to fit more snuggly. At the other end of the scale, if both people wear a surgical mask, which are thinner and provide a looser fit, then the non-infected person has a 10.4 per cent chance of catching Covid
In a previous study, an international team of researchers found mask wearing cut Covid transmission by 53 per cent and social distancing reduced the spread by 25 per cent. They also found handwashing was effective, cutting Covid transmission by 53 per cent however they added the limited number of studies they were able to analyse meant this statistic was not significant
The latest paper, published in the journal PNAS, measured the size and amount of respiratory particles that come out of people’s mouths with various masks on.
They then ran the results through a mathematical model to calculate the risk of a person inhaling them from various distances and lengths of exposure.
It did not look at mask-wearing in the real world, known as a clinical trial, and will probably not be conclusive enough to put to bed the fierce debate about masks.
While lab tests have highlighted huge benefit in mask wearing, real-world studies involving more scientific rigour have produced mixed results, with some showing they have a huge impact on infection rates and others showing virtually none.
Eberhard Bodenschatz, lead author of the latest study and director of the Max Plank Institute at Göttingen, admitted he was surprised at how great the risk of infection was without a mask.
He said: ‘In our study we found that the risk of infection without wearing masks is enormously high after only a few minutes, even at a distance of three meters, if the infected persons have the high viral load of the delta variant of the Sars-CoV-2 virus.
‘We would not have thought that at a distance of several metres it would take so little time for the infectious dose to be absorbed from the breath of a virus carrier.’
The study found that while any mask was better than solely social distancing, the risk was significantly lower depending on how tight and sturdy the mask is.
If both the infected and non-infected person wear well-fitting FFP2 masks, the maximum risk of infection after 20 minutes is one per 1,000, even at a gap of 1.5m.
If they were both to wear the medical masks loosely, then the risk creeps up by 4 per cent.
In a situation where both are wearing well-fitted surgical masks, the most common type, the maximum risk after 20 minutes is one in 10 at the shortest distance.
When both wear poorly-fitted surgical masks then the risk may be as high as 30 per cent, or around one in three.
But the researchers caution that they looked at worst-case scenarios to assess factors that previous studies have been criticised for ignoring – such as people wearing the coverings wrongly.
By simply pulling the face mask above the nose, the risk can be reduced by a factor of up to seven.
It comes after a review of six real-world studies on masks, published in the BMJ, concluded that widespread use can cut Covid rates by up to 53 per cent.
By comparison, social distancing on its own was estimated to reduce transmission by just a quarter.
The review involving nearly 400,000 total participants and was carried out by Monash University researchers in Australia and the University of Edinburgh,
WHAT HAVE STUDIES SHOWN ABOUT FACE MASKS AND COVID?
Research on how well various types of masks and face coverings protect against coronavirus has varied but experts and politicians have generally leaned towards the idea that the chance of some protection is better than none.
In the UK, face coverings were first made mandatory in for public transport in June and later for shops and other indoor spaces in July.
Here’s what studies have shown so far about whether masks work:
FACE MASKS LOWER VIRUS R RATE (JANUARY 2021)
Researchers at Boston University in the US found wearing face masks is an effective way to stop the spread of the coronavirus.
The study, published in the journal Lancet Digital Health, found a 10 per cent rise in self-reported mask wearing is associated with a three-fold increase in the odds of keeping the R number – the number of others each person with coronavirus infects – below 1.
Co-author of the study Ben Rader, of Boston Children’s Hospital and Boston University, said: ‘An important finding of this research is that mask wearing is not a replacement for physical distancing.’
INFECTIOUS DROPLETS WILL STILL SLIP THROUGH (DECEMBER 2020)
Scientists at New Mexico State University in the US found wearing a cloth mask may not shield the user totally from coronavirus because infected droplets can slip through, but it would significantly reduce how many.
‘Wearing a mask will offer substantial, but not complete, protection to a susceptible person,’ said Dr Krishna Kota, an associate professor at the university who led the research.
The study found while all masks blocked at least 95 per cent of droplets from coughs and sneezes – there was still a risk of the disease being passed on.
A MASK ‘WILL ALWAYS BE BETTER THAN NOTHING’ (DECEMBER 2020)
Research by the University of Massachusetts Lowell and California Baptist University in the US found wearing a used three-layer surgical mask can reduce the number of small droplets that are released into the air by two thirds.
Co-author Dr Jinxiang Xi said: ‘It is natural to think that wearing a mask, no matter new or old, should always be better than nothing.
‘Our results show that this belief is only true for particles larger than five micrometers, but not for fine particles smaller than 2.5 micrometers.’
MASK-WEARERS EQUALLY LIKELY TO CATCH VIRUS (NOVEMBER 2020)
A study by Copenhagen University Hospital in Denmark suggested face masks may only offer the wearer limited protection against Covid infection.
Researchers found there was no statistically significant difference in the number of people who contacted the virus in a group wearing masks in public compared to a group that did not do so.
The study was carried out in April and May when Danish authorities did not recommend wearing face coverings.
MASK LEADS TO THOUSANDS FEWER COUGH DROPLETS (AUGUST 2020)
Research by Edinburgh University in Scotland suggested cloth face masks are effective at reducing the amount of droplets spread by coughing or sneezing.
The findings suggest a person standing two metres from someone coughing without a mask is exposed to 10,000 times more droplets than from someone standing half a metre away wearing a basic single layer mask.
Professor Paul Digard, of the University of Edinburgh’s Roslin Institute, said: ‘The simple message from our research is that face masks work.
‘Wearing a face covering will reduce the probability that someone unknowingly infected with the virus will pass it on.’
N95 MEDICAL MASKS COULD PREVENT 99% OF SPREAD (AUGUST 2020)
A study by Duke University in North Carolina, US, found N95 masks are the most effective masks at reducing the spread of Covid-19.
The research published in the journal Science Advances, studied 14 types of face coverings.
Co-author Dr Eric Westman said: ‘If everyone wore a mask, we could stop up to 99 percent of these droplets before they reach someone else.
‘In the absence of a vaccine or antiviral medicine, it’s the one proven way to protect others as well as yourself.’
SURGICAL COVERINGS JUST AS GOOD AS N95 MASKS (MARCH 2020)
A University of Oxford study published on March 30 last year concluded that surgical face masks are just as effective at preventing respiratory infections as N95 respirators for doctors, nurses and other health care workers.
N95 respirators are made of thick, tightly woven and moulded material that fits tightly over the face and can stop 95 percent of all airborne particles, while surgical masks are thinner, fit more loosely, and more porous.
The Oxford analysis of past studies – which has not yet been peer reviewed – found that surgical masks were worth wearing but any face mask is only as good as other health and hygiene practices.
Source: Daily Mail UK