Coupling Within-Host and Between-Host Infectious Diseases Models

Biological processes occur at distinct but interlinked scales of organization. Yet, mathematical models are often focused on a single scale. Recently, there has been a significant interest in creating and using models that link the withinhost dynamics and population level dynamics of infectious diseases. These types of multi-scale models, called immuno-epidemiological models, fall in four categories, dependent on the type of the epidemiological component of the model: network or IBM models, “nested” age-since-infection structured models, ODE models, and “size-structured” models. Immuno-epidemiological multi-scale models have been used to address a variety of questions, including what is the impact of within-host dynamics on population-level quantities such as reproduction number and prevalence, as well as questions related to evolution of the pathogen or co-evolution of the pathogen and the host. Here we review the literature on immuno-epidemiological modeling as well as the main insights these models have created. Keywords-within-host models, between-host models, immuno-epidemiology, mathematical models, differential equations, reproduction number, evolution. AMS SUBJECT CLASSIFICATION: 92D30, 92D40