Spatio-temporal chaos and clustering induced by nonlocal information and vaccine hesitancy in the SIR epidemic model.

Human behavior, and in particular vaccine hesitancy, is a critical factor for the control of childhood infectious disease. Here we propose a spatio-temporal behavioral epidemiology model where the vaccine propensity depends on information that is non-local in space and in time. The properties of the proposed model are analyzed under different hypotheses on the spatio-temporal kernels tuning the vaccination response of individuals. As a main result, we could numerically show that vaccine hesitancy induces the onset of many dynamic patterns of relevance for epidemiology. In particular we observed: behavior-modulated patterns and spatio-temporal chaos. This is the first known example of human behavior-induced spatio-temporal chaos in statistical physics of vaccination. Patterns and spatio-temporal chaos are difficult to deal with, from the Public Health viewpoint, hence showing that vaccine hesitancy can cause them could be of interest. Additionally, we propose a new simple heuristic algorithm to estimate the Maximum Lyapunov Exponent. • Human behavior-based spatio-temporal SIR type epidemic model is considered. • The model includes vaccine hesitancy in relation to childhood immunization. • The behavioral response is assumed to be fully non-local over space and time. • Resulting patterns are triggered by the vaccination response and the spatio-temporal information kernels. • Spatio-temporal chaos is among the observed patterns. [ABSTRACT FROM AUTHOR]