Time delay in a basic model of the immune response

The effects of time delay on the two-dimensional system of Mayer et al., which represents the basic model of the immune response, are analysed (cf. Mayer H, Zaenker KS, an der Heiden U. A basic mathematical model of the immune response. Chaos, Solitons and Fractals 1995;5:155–61). We studied variations of the stability of the fixed points due to the time delay and the possibility for the occurrence of the chaotic solutions.