Population-wide use of facemasks would keep the SARS-CoV-2 reproduction number (R) below 1.0 and prevent further waves of COVID-19 when combined with lockdowns, a modelling study from the University of Cambridge and University of Greenwich suggests.
The research suggests that lockdowns alone will not stop the resurgence of SARS-CoV-2, and that even homemade masks with limited effectiveness can dramatically reduce transmission rates if worn by enough people, regardless of whether they show symptoms or not.
The study found that if people wear masks whenever they are in public, it is twice as effective at reducing R than if masks are only worn after symptoms appear. 100 per cent mask adoption combined with on/off lockdowns prevented any further disease resurgence for the 18 months required for a possible vaccine.
The researchers call for altruistic information campaigns across wealthy and developing nations alike stressing: "My facemask protects you, your facemask protects me."
"Our analyses support the immediate and universal adoption of facemasks by the public," said lead author Dr Richard Stutt from Cambridge University.
"If widespread facemask use by the public is combined with physical distancing and some lockdown, it may offer an acceptable way of managing the pandemic and reopening economic activity long before there is a working vaccine."
Dr Renata Retkute, co-author, said: "The UK government can help by issuing clear instructions on how to make and safely use homemade masks."
"We have little to lose from the widespread adoption of facemasks, but the gains could be significant," the authors say.
