Figure 2

The time series of model (3) in the special case (12), with Figures (a), (b), and (c) representing (respectively) \(S(t)\), \(I(t)\), and \(R(t)\). The parameters of the model are \(b = 10\), \(\mu = 0.65 \), \(\beta = 0.2 \), \(c = 0.77 \), \(\gamma = 0.75 \), \(h=1.5\), \(d=0\), \(p=0\), \(\epsilon =0\), \(\xi = 10\), and \(a=0\). In this case \(\overline{\mathcal{R}_{0}}=1.4179> 1\)