Correlation between multiple protective health behaviors can determine the outcome of disease spread

The impact of human health-related behavior on the spread of the disease continues to be prominent due to the proliferation of sentiment against public health-promoting behaviors. The recent SARS-COV-2 pandemic brought these effects into sharp focus. In the process, we have learned that our current understanding of how human behavior affects disease spread is insufficient in scope and intricacy. In particular, how different health-related behaviors themselves interact with each other, and how those interactions affect disease spread, is largely unknown. In this paper, we use a coupled-contagion model to study the interaction of two different health behaviors — vaccination and mask-wearing. We study how a positive or negative association between these behaviors — e.g. a pro-vaccine person may be more or less likely to be pro-mask-wearing — affects disease dynamics. We find that the strength of such an association alone can determine the outcome of disease spread in the short term and the long term. In addition to studying human health-related behaviors separately, it is vitally important to understand how these behaviors interact with each other and how these associations affect the outcomes of epidemics.