“…However, there is certain debate that this rate is insufficient to realistically describe the infection process. Some authors have incorporated in their models several types of non-linear incidence functions, including saturated Holling type II incidence βT V /(1 + αV ) [3,5,15], Beddington-DeAngelis functional response βT V /(1 + aT + bV ) [6,7], or even more general functions, e.g., of the forms c(T )f (V ) [16] or h(T, V ) [4,8,9].…”