What is the most efficient strategy to prevent SARS-CoV-2 infection?
The main route of SARS-CoV-2 transmission is via respiratory droplets and aerosols.247-249 Avoidance of high virus loads, acquired through aerosol and droplet transmission, is paramount to prevent severe outcomes. Consequently, social distancing, masks and hand sanitation are undoubtedly effective because they prevent the droplet and surface contact-associated initial high virus load and the increased risk of severe disease.250,251 The COVID-19 pandemic can be controlled if social distancing is combined with widespread testing, case isolation, vigorous contact tracing and personal protection. Indeed, severe and critical illness among Chinese healthcare workers before January 10th was 45%, a time when personal protection equipment and infectious control measures were likely not implemented. After February 1st, when personal protection measures were in place, the percentage of severe and critically ill Chinese healthcare workers dropped to 8.7%.252