Feasibility Study of Mitigation and Suppression Intervention Strategies for Controlling COVID-19 Outbreaks in London and Wuhan

Po Yang; Jun Qi; Shuhao Zhang; Xulong Wang; Gaoshan Bi; Yun Yang; Bin Sheng

We modified a SEIR model to account for a dynamic Susceptible Fig.2 . Here, we assume that susceptible population E represents susceptible population of a certain region; and  represents effectiveness of intervention (strict isolation) in contain phase. If effectiveness of intervention in contain phase is not sufficiently strong, susceptible individuals may contract the disease with a given rate when in contact with a portion of exposed population (asymptomatic but infectious) E. After an incubation period, the exposed individuals become the infectious population I (symptomatic) at a ratio α1. Notably, infectious population starts from mild cases M to critical cases C at a ratio α2. Finally, a portion d of critical cases lead to deaths; the rest of infectious population will be recovered.