Are Protective and Social Distancing Measures Effective in Preventing the Spread of COVID-19?
The Lancet published a systematic review and meta-analysis that investigated the optimum distance for avoiding person-to-person virus transmission and assessed the use of face masks and eye protection to prevent transmission of viruses. The study included data for SARS-CoV-2 and the betacoronaviruses that cause severe acute respiratory syndrome, and Middle East respiratory syndrome from 21 standard WHO-specific and COVID-19-specific sources.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 and is spread person-to-person through close contact. The study aimed to investigate the effects of physical distance, face masks, and eye protection on virus transmission in health-care and non-health-care (eg, community) settings.
- Transmission of viruses was lower with physical distancing of 1 m or more and protection was increased as distance was lengthened.
- Face mask use could result in a large reduction in risk of infection, with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar.
- Eye protection also was associated with less infection.
- The findings of this systematic review and meta-analysis support physical distancing of 1 m or more and provide quantitative estimates for models and contact tracing to inform policy.
- Optimum use of face masks, respirators, and eye protection in public and health-care settings should be informed by these findings and contextual factors.
- Robust randomised trials are needed to better inform the evidence for these interventions, but this systematic appraisal of currently best available evidence might inform interim guidance.