Immunization and epidemic threshold of an SIS model in complex networks

We propose an improved mean-field model to investigate immunization strategies of an SIS model in complex networks. Unlike the traditional mean-field approach, the improved model utilizes the degree information of before and after the immunization. The epidemic threshold of degree-correlated networks can be obtained by linear stability analysis. For degree-uncorrelated networks, the model is reduced to the SIS epidemic model in networks after removing the immunized nodes. Compared to the previous results of random and targeted immunization schemes on degree-uncorrelated networks, we find that the infectious disease has a lower epidemic threshold.