Fig. 5.

For the usual choice of parameters $\beta =ln2/2.7$, $\gamma =0.099$, $\delta =10$, $ϵ=2$, we see bi-stability of the time evolution of the epidemic diffusion, fractions u and d, at two different but very close values of the rate $\alpha$. We observe a strong response of the system jumping from a phase of full-blown epidemics to an almost disappearing one