Download This PaperPartial Unlock for COVID-19-Like Epidemics Can Save 1–3 Million Lives Worldwide
17 Pages Posted: 14 Apr 2020 Last revised: 14 Jul 2020
Date Written: May 14, 2020
Abstract
Objectives: We study partial unlock or reopening interaction with seasonal effects in a managed epidemic to quantify overshoot effects on small and large unlock steps and discover robust strategies for reducing overshoot. Methods: We simulate partial unlock of social distancing for epidemics over a range of replication factor, immunity duration and seasonality factor for strategies targeting immunity thresholds using overshoot optimization. Results: Seasonality change must be taken into account as one of the steps in an easing sequence, and a two step unlock, including seasonal effects, minimizes overshoot and deaths. It may cause undershoot, which causes rebounds and assists survival of the pathogen. Conclusions: Partial easing levels, even low levels for economic relief while waiting on a vaccine, have population immunity thresholds based on the reduced replication rates and may experience overshoot as well. We further find a two step strategy remains highly sensitive to variations in case ratio, replication factor, seasonality and timing. We demonstrate a three or more step strategy is more robust, and conclude that the best possible approach minimizes deaths under a range of likely actual conditions which include public response.
Note: Funding: The authors received no external funding for this research.
Conflict of Interest: The authors declare no conflict of interest regarding this research.
Keywords: Coronavirus, COVID-19, pandemic, model, partial unlock, social distancing, economic impact, ventilator utilization, SARS-CoV-2, overshoot
JEL Classification: I12, I15, I10, C02, C61, C63
Suggested Citation: Suggested Citation