People in areas where there is high transmission of Covid-19 should wear face masks indoors, including in offices and schools, according to new guidance from the World Health Organization.
Coverings should also be work in private homes if someone from outside the household enters, social distancing is impossible and ventilation is poor.
Children aged up to five should not wear masks, a ‘risk-based approach’ should be taken for six to 11-year-olds, while those aged 12 and over should follow the same principles as adults, the guidance states.
The advice issued by the UN agency also states masks should be worn even when outside, if social distancing of at least one metre is not possible.
In the updated guidance sheet, the WHO admits there is ‘limited evidence’ the masks stop the transmission of coronavirus.
Recent studies have found conflicting evidence about masks, with a landmark piece of research finding they do not stop the wearer catching the virus.
People in areas where there is high transmission of Covid-19 should wear face masks indoors, including in offices and schools, according to new guidance from the World Health Organization (Stock)
In areas with known or suspected spread of Covid-19, the WHO recommends people should wear a mask indoors and outdoors where distancing of at least one metre cannot be maintained.
The advice, which applies to shops, schools and shared workplaces, also states masks should be worn indoors regardless of social distancing unless ventilation has been assessed to be adequate.
People should also wear a mask at home when receiving visitors if they cannot maintain distancing or ventilation is poor, the WHO recommends.
It also says masks should not be worn during vigorous physical activity.
The WHO said its Covid-19 Guidance Development Group (GDG) ‘considered all available evidence on the use of masks by the general public including effectiveness, level of certainty and other potential benefits and harms, with respect to transmission scenarios, indoor versus outdoor settings, physical distancing and ventilation’.
The recommendations were made ‘despite the limited evidence of protective efficacy of mask wearing in community settings’.
Children aged up to five should not wear masks, a ‘risk-based approach’ should be taken for six to 11-year-olds, while those aged 12 and over should follow the same principles as adults, the guidance states. It also says masks should not be worn during vigorous physical activity (stock)
Last month, scientists warned there is a ‘troubling lack of evidence’ that face masks prevent Covid-19 infection.
It backs up a major study from Denmark which found they don’t protect people who wear them.
Governments around the world — including the UK — have made it mandatory to wear a face covering in indoor public spaces, despite a dearth of rigorous trials into their effectiveness.
The rationale has been that masks must be better than nothing because they block at least some virus being exhaled or inhaled by the wearer.
The randomised study published by scientists at Copenhagen University found no statistical evidence that they offer any protection whatsoever.
Reacting to the finding in a column in The Spectator, Oxford University’s Professor Carl Heneghan and Dr Tom Jefferson said there had been ‘a troubling lack of robust evidence on face masks and Covid-19’.
There have only been three ‘real life’ studies comparing mask-wearers to non-mask-wearers — one in Guinea-Bissau, one in India and the new Denmark study. All have shown masks to have no benefit in preventing the disease.
But the experts added: ‘Now we have properly rigorous scientific research we can rely on, the evidence shows wearing masks in the community does not significantly reduce the rates of infection.’
The Copenhagen experts recruited 6,000 volunteers in the spring — before masks were mandatory there — and split them into two groups, with half wearing masks in public and half not.
After a month, the mask-wearing volunteers were tested for current and previous Covid-19 infection and compared with the control group who didn’t wear them.
Results showed that, after one month, 1.8 per cent of the people wearing masks had been infected with the virus.
By comparison, 2.1 per cent of the people in the unmasked group had tested positive for Covid-19. The difference between the two groups was not found to be statistically significant.
But early in November, the Centers for Disease Control and Prevention (CDC) issued new guidance saying masks do protect wearers from contracting Covid-19.
Previously, the agency said the main benefit of face coverings was to prevent those infected with the virus from spreading it to other people.
Specifically, health officials feared that asymptomatic or pre-symptomatic people may be unaware that they are ill and transmit the disease.
But in the updated recommendations, the CDC stated that cloth masks act as ‘source control’ to block droplets from being exhaled by the wearer and also provide ‘filtration for personal protection’ by preventing droplets from reaching others.
This sentiment is now echoed by the global WHO, which says: ‘Masks can be used either for protection of healthy persons or to prevent onward transmission (source control).’
In respect to so-called source control, masks with valves should not be worn and children under the age of five should not be expected to wear masks.