Homophily impacts the success of vaccine roll-outs

Abstract Physical contacts do not occur randomly, rather, individuals with similar socio-demographic and behavioral characteristics are more likely to interact among them, a phenomenon known as homophily. Concurrently, the same correlate adoption of prophylactic tools. As result, latter unfold homogeneously in population, affecting their ability control spread infectious diseases. Focusing on case vaccines, we reveal that, provided an imperfect vaccine efficacy, three different dynamical regimes exist function mixing rate between vaccinated individuals. Specifically, depending epidemic pressure, coverage find final attack decrease, increase or vary non monotonously respect rate. We corroborate phenomenology through Monte Carlo simulations temporal real-world contact network. Besides our findings hold for any tool that reduces but suppress probability transmission, indicating universal mechanism spreading dynamics.