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

Abstract

Monkeypox (MPX) is a viral zoonotic disease that was endemic to Central and West Africa. However, during the first half of 2022, MPX spread to almost 60 countries all over the world. Smallpox vaccines are about 85% effective in preventing MPX infections. Our objective is to determine whether the vaccines should be mandated or whether voluntary use of the vaccine could be enough to stop the MPX outbreak. We incorporate a standard SVEIR compartmental model of MPX transmission into a game-theoretical framework. We study a vaccination game in which individuals decide whether or not to vaccinate by assessing their benefits and costs. We solve the game for Nash equilibria, i.e., the vaccination rates the individuals would likely adopt without any outside intervention. We show that, without vaccination, MPX 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 equilibria of the vaccination game, and they exhibit a backward bifurcation. Thus, without centrally mandated minimal vaccination rates, the population could easily revert to no vaccination scenario.

Exploring self‐care practices and health beliefs among men in the context of emerging infectious diseases: Lessons from the Mpox pandemic in Brazil

“…Another point highlighted by the study results was the epidemic context of Mpox perceived by men concerning sexual behaviors, where there was a need to reduce the number of sexual and/or affective partnerships, as well as the multiplicity of sexual partnerships and/or casual sex. Additionally, they emphasized, as a population segment, MSM and the vaccination scenario (Augsburger et al, 2022)…”

“…Another point highlighted by the study results was the epidemic context of Mpox perceived by men concerning sexual behaviors, where there was a need to reduce the number of sexual and/or affective partnerships, as well as the multiplicity of sexual partnerships and/or casual sex. Additionally, they emphasized, as a population segment, MSM and the vaccination scenario (Augsburger et al, 2022). The understanding of care practices and their evolution among men facing illness experiences, both in the context of Mpox and in other health situations, is not limited to individual choices alone.…”

Monkeypox: a review of epidemiological modelling studies and how modelling has led to mechanistic insight

“…Building on previous work similar to ref. [ 55 ], Augsburger et al [ 69 ] employ an SVEIR-based model to the 2022 global pandemic and further explore vaccination in a game-theoretic framework where individuals consider cost and benefits to vaccination. They find without vaccination mpox prevalence is predicted to be approximately 3.5 cases per 10 4 individuals, while with optimal voluntary vaccination, prevalence is predicted to be approximately 0.5 cases per 10 4 individuals.…”

Rational social distancing in epidemics with uncertain vaccination timing

“…We also assume that the vaccine works perfectly. This is an idealisation, since vaccines in practice can work imperfectly and it is known that the effectiveness of a vaccine can have an effect on whether individuals decide to get vaccinated or not [9,37,[43][44][45][46][47], thereby increasing the social dilemma's strength. However, the inclusion of vaccine effectiveness would drastically complicate this study and thus lies outside the scope of this work.…”