Fig. 2: Relationship between human mobility and transmission.
a Smoothed combined Apple-Google mobility. b Estimated daily effective reproduction number for infections (red, Rt,i) and delayed effective reproduction at time of deaths (blue, \(R_{t,i}^D\)) estimated using the best-fitting model and mobility data. Effective reproduction number (\(R_{t,i}^{D,EpiEstim}\)) estimated from deaths data alone using a daily 7-day non-overlapping window (black). In each case shading represents the 95% credible interval. Horizontal orange dot and line show the median and 95% CrI for the timing of the change in the relationship between mobility and transmission. c Estimates of the reproduction number against changes in mobility using our best model (5 estimated parameters): green/red lines show the median predictions pre/post change in relationship, with shading indicating the 95% CrI. The ‘EpiEstim’ effective reproduction number using ‘EpiEstim’-like method are shown as error bars in green /orange for approximate pre-post change in relationship with 95% CrI (bands). Results based on the Apple-Google mobility data-stream – equivalent figure using the Apple transit mobility data-stream can be found in the SI (Supplementary Fig. 5); the Apple-related figure shows a qualitatively similar fit but with a marginally better DIC (DIC reduction of 32). Equivalent figures for other countries can be found in the SI (Supplementary Figs. 4–5).
