Estimating cost-benefit of quarantine length for Covid-19 mitigation

Andreas Eilersen; Kim Sneppen

The COVID-19 pandemic has set both governments, health professionals, and epidemiologists in a situation that is more stressful and more rapidly evolving than anything in recent years. Due to the uncertainties caused by a situation in flux, it is difficult to predict anything definite about what works and what does not. The empirical observation that lockdowns worked in both China, and in a milder form in Denmark shows that our use of 75 % reduction in specific infection rates under lockdown is realistic. Our main result is that some of these restrictions can be replaced by testing, 1 step contact tracing and short periods of quarantine. This is far cheaper than total lockdowns. The measures can even work when implemented late in the epidemic. Perhaps most importantly, these measures work best in combination. As is highly relevant to the current epidemic stage of COVID-19, we pinpoint that 1STQ can be successfully implemented also at a late stage of the epidemic where testing may become massively available.