Analysis Of Two SEIR Epidemic Models With Vaccination And Re-infection

Two SEIR epidemic models with vaccination and re-infection are formulated and ana-lyized, one is ODE model, the other is age-structured model. For the ODE epidemic model with vaccination and re-infection, the basic reproduction number is obtained, and the con-dictions under which the model occure backward bifurcation are given; for the age-structured epidemic model with vaccination and re-infection, the expression of the basic reproduction number R((?)) is obtained, it is shown that the disease free equilibrium is globally asymp-totically stable if R0< 1,in this case, the diease disappear; the model exists an endemic equilibrium if R((?))> 1, and in this case, the diease will exist continuously in the population.