Figure 2.
Estimated increase in transmissibility of the 501Y, Flash surveys, France, January 2021
GT: generation time; Reff: effective reproduction number; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2.
A–C. Increased transmissibility of 501Y.V1 variant relative to the classical European lineages, under different assumptions for the GT distribution and the Reff of the classical European lineages.
A. GT distribution with a mean of 6.5 days and a coefficient of variation of 0.62 for both viruses (baseline) for Reff ranging from 0.9 to 1.1.
B. Comparing the baseline estimates to those obtained using a GT distribution with a mean of 5.5 days and coefficient of variation of 0.33 for both viruses and for Reff = 1.0.
C. Increasing the mean GT of the variant from 6.5 (GT difference = 0) to 7.5 (GT difference = 1).
D. Temporal trends for the proportion of 501Y.V1 among SARS-CoV-2 cases.
E. Temporal trends for the expected increase in the effective reproduction number of a person infected with SARS-CoV-2 (averaged across the different variants) in France relative to a scenario where 501Y.V1 would not be circulating in France.
The trends are shown for three values of Reff (0.9 in green, 1.0 in blue, and 1.1 in red). In panels A, B and C, dots represent posterior means while vertical bars represent 95% credible intervals. In panels D and E, solid lines represent posterior means while ribbons represent 95% credible intervals. In panel D, filled diamonds represent data from Flash#1 and Flash#2 used for model calibration; empty diamonds are external validation data (not used for model calibration).
