DGS II 2013 - International Conference and Advanced School Planet Earth , Dynamics , Games and Science II Portugal 28 August to 6 September 2013

In the case of voluntary vaccination, people have to face the benefit of vaccinate against the adverse effects that may result from the act of vaccination. This dilemma is even more important when parents have to decide whether or not to vaccinate their children. The decision depends on the perceived risks from vaccination and infection, but also depends on the decision of all other people: if the most part of population decides to vaccinate, the probability of infection will decrease and the personal interest of an individual may lead to non-vaccination. This game of vaccinate or not vaccinate is analyzed in this work, considering an epidemic model for infection and reinfection. People’s decisions are clear in the case of only one infection, but the possibility of reinfection provides a further diversity and complexity in the decisions that people can take. ∗ Work carried out in collaboration with Alberto A. Pinto.