Impact of Stubborn Individuals on a Spread of Infectious Disease under Voluntary Vaccination Policy

Abstract

Achievement of the herd immunity is essential for preventing epidemics of vaccine-preventable diseases. However, an individual's decision-making whether or not to be vaccinated depends on several factors, such as perceived risks of vaccination and infection, her self-interest, and response of others to vaccination under voluntary vaccination policies. In this study, we consider the case where ``stubborn individuals{''} are presented in lattice populations, who consistently hold the vaccination strategy (stubborn vaccinated individuals) or the no-vaccination strategy (stubborn unvaccinated individuals). We investigate individuals' decision-making process with vaccination by means of modeling the dynamics for epidemic spreading applied to evolutionary game theory. As a result, we find that the presence of stubborn ones, even if it accounts for a small fraction, significantly affect the epidemic spreading and vaccination behavior.