Effectiveness of Non-Pharmaceutical Interventions and Vaccine for Containing the Spread of COVID-19: Three Illustrations Before and After Vaccination Periods

Abstract Background There are few studies demonstrating how the effectiveness of various extents of Non-Pharmaceutical Interventions (NPIs) before and after vaccination periods. The study aimed to demonstrate such an effectiveness in the alteration of the epidemic curves from theory to practice. Methods The empirical data on the daily reported COVID-19 cases were extracted from open source. A computer simulation design in conjunction with the susceptible-exposed-infected-recovered (SEIR) type model was applied to evaluating confinement measures in Italy with adjustment for underreported cases; isolation and quarantine in Taiwan; and NPIs and vaccination in Israel. Results In Italy scenario, the extents of confinement measures were 34% before the end of March and then scaled up to 70% after then. Both figures were reduced to 22-69% after adjusting for underreported cases. Approximately 44% of confinement measures was implemented in the second surge of pandemic in Italy. Fitting the observational data on Taiwan assuming the initial outbreak similar to Wuhan, China, 44% of isolation and quarantine was estimated before 23th March 2020. Isolation and quarantine were scaled up to 90% and at least 60% to contain community-acquired outbreaks from March 24th 2020 onwards. Given 15% monthly vaccination rate from December 2020 in Israel, the effectiveness estimates of reducing the infected toll were 36%, 56%, and 85% for NPIs alone, vaccination alone, and both combined, respectively. Conclusion We demonstrated how various NPIs stamp out and delay the epidemic curve of COVID-19. The optimal implementation of these NPIs has to be planned before wide vaccine uptake worldwide.