Both infectious diseases and behavioral traits can spread via social contacts. Using network-based mathematical models, our study addresses the interplay between these two processes, as disease spreads through a population and individuals copy their social contacts when making vaccination decisions. Imitation can produce clusters of non-vaccinating, susceptible individuals that facilitate relatively large outbreaks of infectious diseases despite high overall vaccination coverage. This may explain, for example, recent measles outbreaks observed in many countries with universal measles vaccination policies. Given that vaccine decisions are likely to be influenced by social contacts and that such imitation can have detrimental epidemiological effects, it is important that policy makers understand its causes, magnitude and implications for disease eradication.
Ndeffo Mbah ML, Liu J, Bauch CT, Tekel YI, Medlock J, et al. (2012) The Impact of Imitation on Vaccination Behavior in Social Contact Networks. PLoS Comput Biol 8(4): e1002469. http://dx.doi.org/10.1371/journal.pcbi.1002469