The observation that the greatest reduction in COVID-19 cases was achieved under the combined [social distancing] intervention is not surprising. However, the assessment of the additional benefit of each intervention, when implemented in combination, offers valuable insight. Since each approach individually will result in considerable societal disruption, it is important to understand the extent of intervention needed to reduce transmission and disease burden.
The effectiveness and societal impact of quarantine and social distancing will depend on the credibility of public health authorities, political leaders, and institutions. It is important that policy makers maintain the public’s trust through use of evidence-based interventions and fully transparent, fact-based communication.
https://www.thelancet.com/journals/lancet/article/PIIS1473-3099(20)30190-0/fulltext