Vaccination behavior as a critical phenomenon Available to Purchase

The 2014–15 measles outbreak at Disneyland in California brought heightened attention to the decision by some people to refuse vaccination for themselves and their children. Such personal decisions play into the complex relationship between vaccination behavior and disease dynamics, which influence each other in a nonlinear feedback loop that also incorporates societal norms and perceived risks. Chris Bauch and his colleagues at the University of Waterloo, Dartmouth College, and École Polytechnique Fédérale de Lausanne have now analyzed Twitter and Google search data related to measles and the measles-mumps-rubella (MMR) vaccine before and after the outbreak. Treating trends in the social-media data as a proxy for trends in the evolution of people’s attitudes toward vaccination, they find signs that the coupled vaccination–disease system was approaching a critical transition, a tipping point leading to a new dynamical regime—in this case an epidemic. The numbers of tweets and Google searches containing measles-related terms...