Fig. 1.

Examples of time series for deterministic (A) and stochastic (B) 3 × 4 × 5 allele models showing the proportion of the population immune to particular strains. Each strain is labeled according to the locus (a, b, and c), with a subscript representing the allele (between 1 and 5). Parameter values for the deterministic model: β = 4, σ = 1, μ = 0.02. (C) Dimensions of strain space at equilibrium for the deterministic model corresponding to A. (D) Dimensions of strain space at equilibrium for the stochastic model corresponding to B. In both, the three-allele locus is represented as layers one behind the other and the strains are colored according to the allele expressed at this locus (e.g., the green squares in C all share allele 3 at locus a).