Fig. 10.

Simulation of different containment strategies (after day 55, for Italy) within the SIR model; the initial parameters are ${\alpha }_0=3.1\ast 10^{-9}$, ${\beta }_0=2∕35$, with $\alpha$ changing to ${\alpha }_1={\alpha }_0∕2$ and to ${\alpha }_2={\alpha }_0∕5$ at days 25 and 35 respectively, see text. After day 55 we consider a dynamics going on with the same parameters (black curve, dashed) together with: one in which the parameter $\alpha$ is further halved, thus getting to ${\alpha }_3={\alpha }_0∕10$, while $\beta$ remains at $\beta ={\beta }_0$ (blue); one with $\alpha$ staying at $\alpha ={\alpha }_2$ while $\beta$ is doubled, thus going at $\beta =2\ast {\beta }_0$ (orange); and one where $\alpha$ is halved and $\beta$ is doubled (red). The plot shows the function $I\left(t\right)$ along the numerical solutions. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)