Imitation dynamics of vaccination behaviour on social networks
Authored by Feng Fu, Daniel I. Rosenbloom, Long Wang, Martin A. Nowak
Date Published: 2011-01-07
DOI: 10.1098/rspb.2010.1107
Sponsors:
China Scholarship Council
John Templeton Foundation
Bill and Melinda Gates Foundation
United States National Institutes of Health (NIH)
National Science Foundation of China
United States National Science Foundation (NSF)
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Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
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Abstract
The problem of achieving widespread immunity to infectious diseases by voluntary vaccination is often presented as a public-goods dilemma, as an individual's vaccination contributes to herd immunity, protecting those who forgo vaccination. The temptation to free-ride brings the equilibrium vaccination level below the social optimum. Here, we present an evolutionary game-theoretic approach to this problem, exploring the roles of individual imitation behaviour and population structure in vaccination. To this end, we integrate an epidemiological process into a simple agent-based model of adaptive learning, where individuals use anecdotal evidence to estimate costs and benefits of vaccination. In our simulations, we focus on parameter values that are realistic for a flu-like infection. Paradoxically, as agents become more adept at imitating successful strategies, the equilibrium level of vaccination falls below the rational individual optimum. In structured populations, the picture is only somewhat more optimistic: vaccination is widespread over a range of low vaccination costs, but coverage plummets after cost exceeds a critical threshold. This result suggests parallels to historical scenarios in which vaccination coverage provided herd immunity for some time, but then rapidly dropped. Our work sheds light on how imitation of peers shapes individual vaccination choices in social networks.
Tags
Epidemiology
evolutionary dynamics
peer influence
mathematical biology
vaccination dilemma