Effective number of infections Supplemental Digital Content 1 – Figure 1. Bayesian skyline plot of the population growth of the Galician F1 cluster. The black line represents the median estimate of the effective number of infections through time, plotted on a logarthmic scale, and the shaded area represents the 95% HPD confidence interval for this estimate. The analysis was done using all PR-RT sequences of the Galician F1 cluster and the 4 closely related sequences from Switzerland and Brazil. Effective number of infections Year