Physical distancing of 1 metre reduces risk by 82%
The efficacy of face masks in reducing SARS-CoV-2 transmission has been contentious.
The efficacy of face masks in reducing SARS-CoV-2 transmission has been contentious. A highly publicized study in Annals of Internal Medicine questioning the utility of surgical or cotton masks has recently been retracted. Derek Chu (McMaster University, Canada) and colleagues, writing in The Lancet, have performed a systematic literature review and meta-analysis of 172 observational and 44 comparative studies to evaluate the efficacy of personal protective equipment in COVID-19 prevention. I have been advocating the use of face masks for several months now, and here is why:
Face masks were associated with protection in both healthcare and community transmission settings, with N95 respirators showing the greatest degree of protection and multilayer masks also showing significant protection. The paper also examines the importance of eye protection (associated with a 78% reduction in risk of infection) and physical distancing (82% reduction in risk at 1 meter).