Estimation of country-level basic reproductive ratios for novel Coronavirus (COVID-19) using synthetic contact matrices

Joe Hilton; Matt J Keeling

In Figure 3 (a) we plot the scaling factors obtained through our consideration of age-dependent susceptibility (figure 2) against the factors obtained by assuming homogeneous susceptibility across age groups (figure 1). Allowing for age-dependent susceptibility substantially increases the amount of variation in scaling (and thus in basic reproductive ratio) by country, and in particular can lead us to predict much larger scaling factors. When the transmission structure is modelled as a simple scaling of a population's contact patterns, the variation in scaling is driven by the variation in average intensity of contacts (captured by the eigenvalue of the contact pattern matrix K) by country. When we incorporate age-dependent susceptibility, contact patterns involving members of highly susceptible age classes becomes particularly important -generating a 3 . CC-BY-NC-ND 4.0 International license It is made available under a author/funder, who has granted medRxiv a license to display the preprint in perpetuity.