Fundamental principles of epidemic spread highlight the immediate need for large-scale serological surveys to assess the stage of the SARS-CoV-2 epidemic

Jose Lourenco; Robert Paton; Mahan Ghafari; Moritz Kraemer; Craig Thompson; Peter Simmonds; Paul Klenerman; Sunetra Gupta

Our overall approach rests on the assumption that only a very small proportion of the population is at risk of hospitalisable illness. This proportion is itself only a fraction of the risk groups already well described in the literature [1] [2] [3] [4] , including the elderly and those carrying critical comorbidities (e.g. asthma). We used a susceptible-infectious-recovered framework (SIRf) to examine the effects of varying the vulnerable fraction of the population on the transmission dynamics of SARS-CoV-2, fixing other model parameters to ranges supported by previous studies (Table 1) . We fit the model to cumulative deaths in the United Kingdom and Italy in the first 15 days following the first recorded death to avoid any potential effects of local control strategies implemented since that time. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.