Fig. 6.

Outbreak dynamics of COVID-19 worldwide. Dynamic effective reproduction number R(t) and symptomatic, asymptomatic, and recovered populations at all nine locations. The simulation learns the time-varying contact rate $\beta \left(t\right)$, and with it the time-varying effective reproduction number $R\left(t\right)$, to predict the symptomatic infectious, asymptomatic infectious, and recovered populations $I_{\mathrm{s}}$, $I_{\mathrm{a}}$, and $R$, for fixed latent and infectious periods $A=2.5$ days, $C_{\mathrm{s}}=6.5$ days, the hierarchical asymptomatic infectious period $C_{\mathrm{a}}$$=$ 5.76 (95%CI: 3.59–8.09) days from Fig. 5. The dashed vertical lines mark the first time each location managed to lower the effective reproduction below $R\left(t\right)=1$ after lockdown. The colored regions highlight the 95% credible interval for the effective reproductive number $R\left(t\right)$ (top), the symptomatic and asymptomatic populations $I_{\mathrm{s}}$ and $I_{\mathrm{a}}$, and the recovered population $R$ (bottom plots), for uncertainties in the number of confirmed cases $D$, the fraction of the symptomatic infectious population ${\nu }_{\mathrm{s}}$, the initial exposed population $E_0$, and the initial infectious populations $I_{\mathrm{s0}}$ and $I_{\mathrm{a0}}$.