OICC Press International Journal of Mathematical Modelling & Computations 2228-6233 11 4 2021 12 01 Stability Analysis of a Staged Progression Susceptibility Model for Infectious Diseases 1 37 10.30495/ijm2c.2021.685128 EN Jean Pierre II KOUENKAM Department of Mathematics, Faculty of Science, University of Yaounde I, Yaounde, Cameroon Gilbert Chendjou Department of Mathematics, Faculty of Science, University of Yaounde I, Yaounde, Cameroon Jose MBANG Laboratory of Applied Mathematics, Department of Mathematics, Faculty of Science, University of Yaounde I, Yaounde, Cameroon Yves EMVUDU Department of Mathematics, Faculty of Science, University of Yaounde I, Yaounde, Cameroon Journal Article 2021 12 01 The aim of this paper is to provide a stability analysis for models with a general structure and mass action incidence; which include stage progression susceptibility, differential infectivity as well, and the loss of immunity induced by the vaccine also. We establish that the global dynamics are completely determined by the basic reproduction number R0. More specifically, we prove that when R0 is smaller or equal to one, the disease free equilibrium is globally asymptotically stable; while when it is greater than one, there exist a unique endemic equilibrium. We also provide sufficient conditions for the global asymptotic stability of the endemic equilibrium.