本文讨论带二次感染和接种疫苗的年龄结构MSEIR流行病模型。在常数人口规模的假设下,运用微分方程和积分方程中的理论和方法,得到一个与接种疫苗策略ψ有关的再生数R(ψ)的表达式,证明了当R(ψ)<1时,无病平衡态是局部渐近稳定的;当R(ψ)>1时,无病平衡态是不稳定的,此时存在一个地方病平衡态,并且证明当R(0)<1时,无病平衡态是全局渐近稳定的。 This article discusses the age-structured MSEIR epidemic model with secondary infection and vaccination. Under the assumption of constant population size, using the theory and method of differential equation and integral equation, we get an expression of R (ψ) related to vaccination strategy ψ, and prove that when R (ψ) <1, The disease-free equilibrium is locally asymptotically stable; when R (ψ)> 1, the disease-free equilibrium is unstable, at which point there is a endemic balance, and it is proved that when R (0) <1, The equilibrium state is globally asymptotically stable.