title: Rational exemption to vaccination for non-fatal SIS diseases: globally stable and oscillatory endemicity.
abstract: 'Rational' exemption to vaccination is due to a pseudo-rational comparison between the low risk of infection, and the perceived risk of side effects from the vaccine. Here we consider rational exemption in an SI model with information dependent vaccination where individuals use information on the disease's spread as their information set. Using suitable assumptions, we show the dynamic implications of the interaction between rational exemption, current and delayed information. In particular, if vaccination decisions are based on delayed informations, we illustrate both global attractivity to an endemic state, and the onset, through Hopf bifurcations, of general Yakubovich oscillations. Moreover, in some relevant cases, we plot the Hopf bifurcation curves and we give a behavioural interpretation of their meaning.
authors.affiliation: Department of Mathematics and Applications, University of Naples Federico II, via Cintia, I-80126 Naples, Italy. buonomo@unina.it
authors.forename: Bruno
authors.initials: B
authors.lastname: Buonomo
authors.forename: Alberto
authors.initials: A
authors.lastname: D'Onofrio
authors.forename: Deborah
authors.initials: D
authors.lastname: Lacitignola
mesh_terms: D003140:Communicable Disease Control; D003141:Communicable Diseases / Q000453:epidemiology / Q000276:immunology*; D003198:Computer Simulation; D004196:Disease Outbreaks / Q000517:prevention & control*; D006801:Humans; D018448:Models, Immunological; D014611:Vaccination; D014612:Vaccines / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D014612:Vaccines