Figure 1

Schematic example of a host-pathogen system within the multilocus framework. A schematic of overlapping compartments is used to indicate the proportions immune to each strain (Z) and to antigenically related variants (W), from which the proportion of infectious (Y) can be deduced (for simplicity, a {2,2} antigenic system is presented, see main text for model equations). The background grey Venn diagrams present all the possible overlaps between the Z and W subclasses. Colours are used to highlight the sections of the diagrams related to each strain: AX in green, AY in red, BX in blue and BY in purple. On the top row, Z classes are presented. On the bottom row W classes are presented, which include the intersection of multiple Z classes according to the allele-sharing relationships between strains.