Figure 6.

City B with a complex immune response. ‘k’ Denotes thousand and ‘L’ denotes hundred thousand. W/7 denotes the weekly increments in cases scaled down by 7 as described previously, while HVF and LVF refer to the higher and lower virulence forms of the disease, respectively. y Is shown in blue, $\dot{y}$ in green, z in red, $\dot{z}$ in magenta, and the epi-curves in grey for y and cyan for z.