Results
In the following sections, we provide figures to demonstrate the effect of metapopulation structure on disease dynamics. In these figures, we plot a time series for each of three subsets of the population: those currently infected with a particular strain of the pathogen, those having (complete) specific immunity against the focal strain, and those who have at least partial cross-reactive immunity to the focal strain, due to past exposure to a similar strain (see Methods). Populations differ in their β (and thus R0) value. This can be considered, for example, as differences in population density, which affects the probability of disease transmission. We only depict one representative strain in each plot for visual clarity and parametrize the model such that all strains are functionally equivalent (i.e. they all have the same transmission and recovery rates within any given population).