Fig. 3: Rebound of infections after vaccination in the coexistence and eradication regimes.
From: Rebound in epidemic control: how misaligned vaccination timing amplifies infection peaks
Illustrative example of the effects of limited-time vaccination in two different vaccination regimes. On the left, the vaccination rate α falls in the coexistence regime (α = 0.003), while on the right it is in the eradication regime (α = 0.008). The shaded area denotes the time period when the vaccination strategy is active. In both regimes, when the vaccination stops, a resurgence wave is observed, but with a different magnitude: in the coexistence regime, the wave is relatively modest, whereas in the second scenario, it is more pronounced, comparable in size to the initial wave. This observation suggests that a higher intensity of vaccination efforts may paradoxically exacerbate the rebound effect. Simulation with β = 1, μ = 0.5, δ = 0.01 and a vaccination campaign taking place between t = 400 and t = 600. The initial conditions are I(0) = 0.01 and S(0) = 0.99.
