Global convergence of COVID-19 basic reproduction number and estimation from early-time SIR dynamics

Gabriel G. Katul; Assaad Mrad; Sara Bonetti; Gabriele Manoli; Anthony J. Parolari

is the (which was not peer-reviewed) The copyright holder for this preprint . https://doi.org/10.1101/2020.04.10.20060954 doi: medRxiv preprint Examples for specific countries are also featured in Figure 3 illustrating the same early 175 slope patterns. Mindful of all the pitfalls in determining R o [17] , the global estimate 176 here of R o = 4.5 is roughly commensurate with other entirely independent estimates for 177 COVID-19. The most recent update from the China study suggests an R o = 4.1 [25] 178 whereas for France, the most recent estimate for early times is R o = 4.9 [26] . The 179 initially reported and the much cited R o = 2.2 value [4] from Wuhan, China appears to 180 be low [27] . A more elaborate estimate of R o based on case reports, incubation periods, 181 high-resolution real-time human travel data, infection data combined with agent-based 182 mathematical models result in R o = 4.7 − 6.6 [27] . Other studies report values between 183 3.3 and 6.6 [28] . It must be emphasized that the R o determined here reflects The same analysis performed for World countries is now applied at a sub-national level, 189 considering Upper Tier Local Authorities (UTLAs) in the UK and provinces in Italy 190 (Fig. 4) . Results show a higher variability than country-level data (as expected) but the 191 theoretical 'boundary-line' of R o = 4.5 is shown to hold also at finer spatial scales. . CC-BY-NC 4.0 International license It is made available under a author/funder, who has granted medRxiv a license to display the preprint in perpetuity.