  We interpret attitudes towards science and pseudosciences as cultural traits
that diffuse in society through communication efforts exerted by agents. We
present a tractable model that allows us to study the interaction among the
diffusion of an epidemic, vaccination choices, and the dynamics of cultural
traits. We apply it to study the impact of homophily between pro-vaxxers and
anti-vaxxers on the total number of cases (the cumulative infection). We show
that, during the outbreak of a disease, homophily has the direct effect of
decreasing the speed of recovery. Hence, it may increase the number of cases
and make the disease endemic. The dynamics of the shares of the two cultural
traits in the population is crucial in determining the sign of the total effect
on the cumulative infection: more homophily is beneficial if agents are not too
flexible in changing their cultural trait, is detrimental otherwise.
