Time to encourage people to wear face masks as a precaution

Professor Trisha Greenhalgh at the University of Oxford and colleagues said despite limited evidence, masks "could have a substantial impact on transmission with a relatively small impact on social and economic life."

"Masks are simple, cheap, and potentially effective. We believe that wearing both in the home (particularly by the person showing symptoms) and also outside the home in situations where meeting others is likely (for example, shopping, public transport), they could have a substantial impact on transmission with a relatively small impact on social and economic life," said researchers.

However, the question of whether masks will reduce transmission of COVID-19 in the general public is contested.Although clinical trial evidence on the widespread use of facemasks as a protective measure against COVID-19 is lacking, at the time of writing increasing numbers of agencies and governments, including the US Centres for Diseases Control and Prevention, are now advocating that the general population wears masks, but others, such as the World Health Organization and Public Health England are not.

Some researchers argue that people are unlikely to wear masks properly or consistently, and may ignore wider infection control measures like handwashing. Others say the public should not wear them since healthcare workers need them more.But the current study, published in the journal The BMJ challenge these arguments and suggest that in the context of COVID-19, many people could be taught to use masks properly and may well do this consistently without abandoning other important anti-contagion measures.

According to the researchers, if the political will is there, mask shortages can be quickly overcome by repurposing manufacturing capacity - something that is already happening informally. They concluded that it is time to act without waiting for randomised controlled trial evidence.

Even researchers at Tsinghua University in China agreed that the public should wear face masks because the benefits are plausible and harm unlikely. They also said that cloth masks are likely to be better than wearing no mask at all.