Fig. 3
From: Epidemic cycling in a multi-strain SIRS epidemic network model
The effect of cross-immunity on the oscillatory phase. The parameter area for cycling epidemics (II) increases with cross-immunity but reduces rapidly when cross-immunity becomes complete. Other parameters: κ = 8, λ = 10 and two birth rates are assumed: μ = 0.0005 (solid line) and μ = σ (dashed line). In the later situation the threshold waning rate of immunity nearly halves, which indicates that most of individuals stay in the recovery and immune compartments