Anguelov, RoumenGarba, Salisu M.Usaini, Salisu2014-07-212014-07-212014-11Anguelov, R, Garba, SM & Usaini, S 2014, 'Backward bifurcation analysis of epidemic model with partial immunity', Computers and Mathematics with Applications, vol. 68, no. 9, pp. 931-940.0898-1221 (print)1873-7668 (online)10.1016/j.camwa.2014.06.010http://hdl.handle.net/2263/40895This paper presents a two stage SIS epidemic model in animal population with bovine tuberculosis (BTB) in African buffalo as a guiding example. The proposed model is rigorously analyzed. The analysis reveals that the model exhibits the phenomenon of backward bifurcation, where a stable disease-free equilibrium (DFE) coexists with a stable endemic equilibrium (EE) when the associated reproduction number (Rv) is less than unity. It is shown under two special cases of the presented model, that this phenomenon of backward bifurcation does not arise depending on vaccination coverage and efficacy of vaccine. Numerical simulations of the model show that, the use of an imperfect vaccine can lead to effective control of the disease if the vaccination coverage and the efficacy of vaccine are high enough.en© 2014 Elsevier. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Computers and Mathematics with Applications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Computers and Mathematics with Applications, vol. 68, no. 9, pp. 931-940, 2014. doi : 10.1016/j.camwa.2014.06.010 .Backward bifurcationVaccineBovine tuberculosis (bTB)African buffalo (Syncerus caffer)Postprint Article