Fig. 9.

Monotone increasing, monotone decreasing, and non-monotone dependence of the endemic equilibrium on $q$. Parameters are the same as before, except that in a ${\mathit{\alpha }}_{21}^S=2\times {\mathit{\alpha }}_{12}^S=0.2,{\mathit{\beta }}_1=0.3,{\mathit{\beta }}_2=0.1,{\mathit{\beta }}^T=0.7$, and in b ${\mathit{\beta }}_1=0.25,{\mathit{\beta }}_2=0$