COVID-19 vaccination and the behavioral immune system: The newcomer and the old friend get along in preventing infection

Despite its old evolutionary history and emotional relevance, the behavioral immune system is one of the less studied individual predictors of vaccine uptake. To fill the gap, we conducted a large online study (2072 participants) during the spring 2022 when the great majority of the Italian population had already received at least one dose of the COVID-19 vaccine. Hierarchical binary logistic regression showed that, after controlling for the confounding effects of demographic and personality factors, there was a significant and positive association between pathogen disgust sensitivity and COVID-19 vaccine uptake (OR, 1.68; 95% CI, 1.42–1.99). The likelihood of being vaccinated for a participant with the highest possible score on the PVD Germ Aversion scale was approximately 12 times higher than the likelihood for a participant with the lowest possible score. Public health messaging could leverage the activation of the behavioral immune system as an emotional driver of vaccine uptake.