An effective immunization strategy for airborne epidemics in modular and hierarchical social contact network

• We pointed out the disadvantage of traditional targeted immunization.
• We proposed a hierarchical targeted immunization strategy to improve the disease control better.
• We analyzed the importance of hierarchical structure in a network in controlling epidemic propagation.
• We validated the efficiency and stability of the hierarchical targeted immunization strategy.

Social contact between individuals is the chief factor for airborne epidemic transmission among the crowd. Social contact networks, which describe the contact relationships among individuals, always exhibit overlapping qualities of communities, hierarchical structure and spatial-correlated. We find that traditional global targeted immunization strategy would lose its superiority in controlling the epidemic propagation in the social contact networks with modular and hierarchical structure. Therefore, we propose a hierarchical targeted immunization strategy to settle this problem. In this novel strategy, importance of the hierarchical structure is considered. Transmission control experiments of influenza H1N1 are carried out based on a modular and hierarchical network model. Results obtained indicate that hierarchical structure of the network is more critical than the degrees of the immunized targets and the modular network layer is the most important for the epidemic propagation control. Finally, the efficacy and stability of this novel immunization strategy have been validated as well.