Simulated epidemic curves for five populations, when there is (A) no vaccine effect, (B) an effective all-or-none vaccine, and (C) an effective leaky vaccine. Darker lines correspond to areas with lower vaccination coverage. Corresponding effective reproductive numbers are included with vaccination coverage in the legend. A, No vaccine effect (= 0); B, All-or-none vaccine (= 0.8); C, Leaky vaccine (= 0.8)