The widespread use of facemasks could push Covid-19 transmission down to controllable levels and prevent further waves when combined with lockdowns, according to a UK study published on Wednesday.
The research, led by scientists at Britain's Cambridge and Greenwich Universities, suggests lockdowns alone will not stop the resurgence of the new outbreaks of the novel coronavirus, but that even home-made masks can dramatically reduce transmission rates if enough people wear them in public.
"Our analysis supports the immediate and universal adoption of face masks by the public," said Richard Stutt, who co-authored the study with Renata Retkute at Cambridge.
He said the findings showed that if widespread mask use were combined with social distancing and some lockdown measures, this could be "an acceptable way of managing the pandemic and re-opening economic activity" long before the development and public availability of an effective vaccine against Covid-19, the respiratory illness caused by the coronavirus.
The study's findings were published in the Proceedings of the Royal Society scientific journal.
The World Health Organisation updated its guidance on Friday to recommend that governments ask everyone to wear fabric face masks in public areas where there is a risk in order to reduce the spread of the disease.
In this study, researchers linked the dynamics of spread between people with population-level models to assess the effect on the disease's reproduction rate, or R-value, of different scenarios of mask adoption combined with periods of lockdown.
The R-value measures the average number of people to whom one infected person will pass on the disease. An R-value above 1 can lead to exponential growth.
The study found that if people wear masks whenever they are in public, it is twice as effective at reducing the R-value than if masks are only worn after symptoms appear.
In all scenarios the study examined, routine use of face masks by 50 per cent or more of the population reduced Covid-19 spread to an R of less than 1, flattening future disease waves and allowing for less stringent lockdowns.
"We have little to lose from the widespread adoption of face masks, but the gains could be significant," Dr Retuke said.
