The effect of inter-city travel restrictions on geographical spread of COVID-19: Evidence from Wuhan, China

Billy J Quilty; Charlie Diamond; Yang Liu; Hamish Gibbs; Timothy W Russell; Christopher I Jarvis; Kiesha Prem; Carl A B Pearson; Samuel J Clifford; Stefan Flasche; Petra Klepac; Rosalind M Eggo; Mark Jit

As recent studies have shown (7, 8, 23) , strict physical distancing measures soon decreased the effective reproduction number to 1 or less in Wuhan and other cities in China. By incorporating this decrease into our model, we find that cordons sanitaires alone, implemented after outbreaks were likely to be established in other cities, were likely ineffective in stopping outbreaks of COVID-19 in other major population centres. To have a greater impact, the cordon sanitaire would need to be implemented earlier, as investigated in Lai et al. 2020 (16) , and be accompanied by other NPIs, such as general physical distancing and school and work closures (7, 18) . Similarly, it is unlikely that cordons sanitaires in other countries with well-established, geographically dispersed outbreaks will substantially delay COVID- 19 spread. An open question is whether travel . CC-BY 4.0 International license It is made available under a author/funder, who has granted medRxiv a license to display the preprint in perpetuity.