A social structure model for evaluating the effect of response measures on the spread of smallpox

Abstract

Homogeneous mixing, where all instances of contacts between any two members of the population are equally likely, is a common assumption in modeling biodefense policies against smallpox. Such a mixing pattern is rather unlikely to represent population interaction in a modern urban setting, which typically is separated into households on one hand, and into daily meeting sites such as school and offices, on the other hand. In this paper we develop a dynamic two-level social interaction model where individuals move back and forth between home and daily meeting sites, possibly passing through a general meeting site such as a mass transit system or other crowded areas. Based on this difference-equations model, we evaluate the effect of situational awareness and response measures, such as vaccination, quarantining and movement restrictions, on the spread of smallpox in the population.