Fig. 4From: The optimal vaccination strategy to control COVID-19: a modeling study in Wuhan City, ChinaThe flowchart of vaccinated age-specific SEIAR model (Model 3, considering the vaccine efficacy of susceptibility and infectivity). i and j represent age ≤ 14, 15‒44, 45‒64, and ≥ 65, respectively (i ≠ j)Back to article page