Masks and social distancing can help control the coronavirus, but hand washing and other measures are still needed, a new study has found.
Researchers concluded single-layer cloth masks are less effective than surgical masks, while tight-fitting N95 masks provide the best protection, according to the study published in the medical journal, The Lancet.
A distance of one metre (more than three feet) between people lowers the danger of catching the virus, while two metres (about 6.5 feet) is even better.
Eye protection such as eyeglasses or goggles can help, too. None of the strategies works perfectly, and more rigorous studies are needed, according to the analysis.
With this coronavirus still new, health officials have relied on studies involving its cousins, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).
The findings come from a systematic review of 44 studies, including seven involving the virus causing COVID-19. The remaining focused on SARS or MERS.
“This puts all that information clearly in one place for policymakers to use,” said study co-author Dr Derek Chu of McMaster University in Hamilton, Ontario, Canada.
Still to come are results from more rigorous experiments in Canada and Denmark that are testing masks in randomly assigned groups of nurses and the general public.
Until then, the Lancet study provides reassurance that masks do help.
Public health officials have given conflicting advice about masks.
The World Health Organization, which funded the new analysis, has said healthy people need to wear a mask only if they are caring for a person with COVID-19.
The US Centers for Disease Control and Prevention has advised people in the US to wear at least a cloth mask when grocery shopping or in similar situations where keeping distance is difficult. Other countries have made wearing a mask compulsory when going outside.