[Mathematical model of the immune response. IV. Threshold character of the infectious process].

A model of immune reaction is described which takes into account the agressive behaviour of infectious microorganisms in the macroorganism. The model allows a description of threshold relationship between the infection process and the initial dose of the antigen. According to the model depending on the parameters and initial data the following regimes are possible: destruction of the antigen without a disease, its destruction after a disease, coexistence of the antigen with specific antibodies, recurrent course of the disease, unlimited multiplication of the antigen.