Figure 2.
Predictions of the model incorporating immune memory, showing the dynamic outcomes of the pathogen–immune system interaction as functions of r, the pathogen replication rate, c, the immune pathway shape parameter and δ, the rate of memory decay. Eradication of the pathogen (defined as when P (t) falls below 0.007 and is then bounded at 0, else the dynamic is defined as unstable) is ensured through numerical simulations (using a fourth order Runge–Kutta algorithm with step size (dt) of 10−3). The insets show: (i) stable chronic infection (r=2, c=6) above the stability boundaries and (ii) pathogen exclusion (r=4, c=1) below the stability boundaries.