Dynamics of Single-City Influenza with Seasonal Forcing: From Regularity to Chaos

Figure 2

Dynamics without loss of individual immunity or seasonal forcing. There is no loss of individual immunity (𝑘_rec=0; (10), Figure 1) nor seasonal forcing ((18); 𝑠_env=0). (a) Short-term dynamics. (b) Long-term dynamics. Parameters and initial conditions have the values in Table 1. Successive epidemics are caused by loss of immunity at the population level from the natural birth and death processes (μ, (2), Table 1).

(a)

(b)