title: Role of incidence function in vaccine-induced backward bifurcation in some HIV models.
abstract: The phenomenon of backward bifurcation in disease models, where a stable endemic equilibrium co-exists with a stable disease-free equilibrium when the associated reproduction number is less than unity, has important implications for disease control. In such a scenario, the classical requirement of the reproduction number being less than unity becomes only a necessary, but not sufficient, condition for disease elimination. This paper addresses the role of the choice of incidence function in a vaccine-induced backward bifurcation in HIV models. Several examples are given where backward bifurcations occur using standard incidence, but not with their equivalents that employ mass action incidence. Furthermore, this result is independent of the type of vaccination program adopted. These results emphasize the need for further work on the incidence functions used in HIV models.
authors: Department of Mathematics, University of Manitoba, Winnipeg, MAN, Canada.
authors: O
authors: O
authors: Sharomi
authors: C N
authors: CN
authors: Podder
authors: A B
authors: AB
authors: Gumel
authors: E H
authors: EH
authors: Elbasha
authors: James
authors: J
authors: Watmough
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology*; D050936:Basic Reproduction Number; D015658:HIV Infections / Q000453:epidemiology / Q000276:immunology* / Q000517:prevention & control / Q000821:virology*; D015497:HIV-1 / Q000254:growth & development* / Q000276:immunology; D006801:Humans; D015994:Incidence; D008954:Models, Biological
chemical_list: D016915:AIDS Vaccines