Fig. 4
Estimated date on which the probability of an outbreak exceeds 95% in the 4 cities of interest, for Chunyun vs. non-Chunyun and cordon sanitaire imposed vs. no cordon sanitaire and for varying values of the overdispersion parameter k [15, 21, 22]. Median (and 95% CI) estimated cumulative number of infections on 1 March in the four cities of interest, Chunyun vs. non-Chunyun, cordon sanitaire imposed vs. no cordon sanitaire, and for varying values of Re, where R = 2.2 (no change, unmitigated local outbreak), reduced from 2.2 by 50% to 1.1 (mitigation of outbreak, R > 1), and 75% to 0.55 (suppression of outbreak, R < 1)