Title: Voluntary vaccination may not stop monkeypox outbreak: A game-theoretic model

Abstract: Mpox (formerly monkeypox) is a viral disease that recently spread to almost 60 countries all over the world. Our main goal is to determine whether the smallpox vaccines, which are about 85% effective against mpox, should be mandated or whether voluntary use of the vaccine could be enough to stop the mpox outbreak. We study a vaccination game in which individuals decide whether or not to vaccinate by assessing their benefits and costs. We show that, without vaccination, mpox can become endemic in previously non-endemic regions, including the United States. We also show that to “not vaccinate” is often an optimal solution from the individual’s perspective. Moreover, we demonstrate that, for some parameter values, there are multiple solutions of the vaccination game and without centrally mandated minimal vaccination rates, the population could easily revert to no vaccination scenario.