What the reproductive number R_0 can and cannot tell us about COVID-19 dynamics

• DOI: 10.48550/arxiv.2006.14676
• Publication Date: 2020-01-01
• Authors: Clara L. Shaw; David Kennedy
• Keywords: Pandemic; Confusion; Basic reproduction number; 2019-20 coronavirus outbreak

The reproductive number R_0 (and its value after initial disease emergence R) has long been used to predict the likelihood of pathogen invasion, gauge potential severity an epidemic, and set policy around interventions. However, often ignored complexities have generated confusion use metric. This is particularly apparent with emergent pandemic virus SARS-CoV-2, causative agent COVID-19. We address some these misconceptions, namely, how R changes over time, varies space, relates epidemic size by referencing mathematical definition examples from current pandemic. hope that a better appreciation uses, nuances, limitations facilitates understanding spread, severity, effects interventions in context SARS-CoV-2.