Potential impact of seasonal forcing on a SARS-CoV-2 pandemic

Richard A Neher; Robert Dyrdak; Valentin Druelle; Emma B Hodcroft; Jan Albert

pandemic could unfold, not as a prediction of any particular scenario. The results we present are critically dependent on the assumptions i) that the outbreak will develop into a pandemic, ii) that the transmissibility of SARS-CoV-2 shows seasonal variability of sufficient strength (range ε = 0.3 to 0.7), and iii) that parameters like R 0 estimated from the early phase of the outbreak are comparable in other populations. These assumptions are not implausible but not certain: cases of SARS-CoV-2 has been in several countries in Asia apart from China, as well as in Europe, Africa, North America, and Australia (WHO Emergency Committee, 2020b), and mild or asymptomatic cases make detection and thus prevention of spread by isolation challenging, e.g. airport screening as a preventive measure is unlikely to prevent spread and local seeding (Quilty et al., 2020) . Person-to-person transmission of the virus has been documented in several countries outside of China, including large outbreaks in Iran, South Korea, and Italy (European Centre for Disease Prevention and Control (ECDC), 2020). It is likely that not all exported cases have been detected, and some may have seeded outbreaks outside of China that have yet to be detected.