ABSTRACT
Particular emphasis is that a major difference between fractional order models and integer order models is that fractional order models possess memory [5,12], while the main features of immune response involve memory [18]. Hence, we attempt to model HIV infection with immune response using a fractional order system. Our presentation is based on the immune model of HIV infection which is developed by Iwami et al. [4]. For the one-virus model, we carry out a detailed analysis on stability of equilibrium. Our analysis shows that the interior equilibrium which is unstable in the classical integer order model can become asymptotically stable in our fractional order model. We also fi nd that chaos does exist in the fractional order HIV model with viral diversity.
