El-Sayed A.M.A.Arafa A.A.M.Khalil M.Sayed A.Department of mathematicsFaculty of ScienceAlexandria UniversityAlexandriaEgypt; Department of MathematicsFaculty of SciencePort Said UniversityPort SaidEgypt; Department of MathematicsFaculty of EngineeringOctober University for Modern Sciences and Arts (MSA University)GizaEgypt2020-01-092020-01-09201723569336https://doi.org/10.18576/pfda/030404http://www.naturalspublishing.com/files/published/12g3g36uc8nxq1.pdfScopusAn epidemiological fractional order model which displays backward bifurcation for some parameters values, is studied in this paper. Because integer order of such model does not convey any information about the effect of the memory or learning mechanism of human population which influences disease transmission, we use the fractional order model in which the memory effect is considered well. As the fractional derivative is considered as the memory index, so the goal of this paper is to study the impact of fractional order derivative on the backward bifurcation phenomenon and on the basic reproduction number R0. � 2017 NSP.EnglishComputer virusFractional calculusNumerical solutionPredictor-corrector methodArticlehttps://doi.org/10.18576/pfda/030404