Global Analysis of an Epidemic Model with Latent Period and Partial Immunity

Under the assumption that the vaccinated individuals have partial immunity,an SEIR epidemic model with Latent period and vaccination was established,and the basic productive number determining the dynamics of the model was obtained.When the basic productive number is less than 1,the model only has the disease-free equilibrium;when the basic productive number is greater than 1,in addition to the disease-free equilibrium,the model also has a unique endemic equilibrium.By means of Liapunov function,the global stability of the disease-free equilibrium and endemic equilibrium was proved.