Figure 1
From: Exploring Voluntary Vaccinating Behaviors using Evolutionary N-person Threshold Games
The effects of herd immunity threshold and population size on the fraction of vaccinated individuals at equilibrium. The upper two figures show the effects of population size under the threshold M = 1 and M = 2, respectively. The following two figures show the effects of threshold and basic reproduction number R 0 when the population size N = 5 and N = 10, respectively. It can be observed that as the relative cost c increases, the fraction of vaccinated individuals at equilibrium decreases nonlinearly for fixed population size N and threshold M. When the relative cost c is large enough, unvaccinated individuals will dominate the whole population.
