The global spread of SARS-CoV-2 has taken a variety of forms, ranging from localized and quickly controlled outbreaks to large, ongoing epidemics with deadly consequences. As a result, scientific inquiries seeking to understand viral spread and its drivers across spatial scales have exploded. In a Perspective, Elizabeth Lee and colleagues argue that such a rapidly developing body of research, which has led to vigorous and highly politicized debate concerning newly emerging facets of the novel coronavirus, may create the impression that our understanding of COVID-19 spread is frequently overturned or not well understood at all. "Although our knowledge of SARS-CoV-2 transmission is constantly deepening in important ways, the fundamental engines that drive the pandemic are well established and provide a framework for interpreting this new information," write Lee et al. The authors offer an overview on the established knowns of SARS-CoV-2 spread across various contexts and spatial scales, including household, residential and community settings and during superspreading events. They highlight when these transmission-spreading events can be considered part of a more general phenomenon: overdispersion in transmission, or more of a variation in cases than expected. This phenomenon has driven much of the debate around the relative importance of different modes of transmission, they note. They also highlight distinct unknowns. "The relative risk of transmission in different community settings, such as restaurants and retail stores, is still unclear, as is the impact of mitigation measures in these contexts," write the authors. "Filling these and other knowledge gaps will clarify how the engines of transmission interact to drive the pandemic and how to fight back."
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Journal
Science