Three behavioral-epidemic models (i.e. epidemic systems including feedbacks that the information about an infectious disease has on its spreading) are introduced. Two relevant feedbacks are explicitly considered: the pseudo-rational exemption to vaccination and the information--related changes in contact patterns by healthy subjects.
The global stability analysis of the endemic states is performed by means of the geometric approach to stability, with particular focus on a model of vaccination of adult susceptible subjects. Biological implications of the results are discussed.
