Vaccination and the theory of games
- Chris T. Bauch † , ‡ and
- David J. D. Earn §
- †Department of Mathematics and Statistics, University of Guelph, Guelph, ON, Canada N1G 2W1; and §Department of Mathematics and Statistics, McMaster University, Hamilton, ON, Canada L8S 4K1
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Edited by Maurice R. Hilleman, Merck Institute for Vaccinology, West Point, PA, and approved July 21, 2004 (received for review May 28, 2004)
Abstract
Voluntary vaccination policies for childhood diseases present parents with a subtle challenge: if a sufficient proportion of the population is already immune, either naturally or by vaccination, then even the slightest risk associated with vaccination will outweigh the risk from infection. As a result, individual self-interest might preclude complete eradication of a vaccine-preventable disease. We show that a formal game theoretical analysis of this problem leads to new insights that help to explain human decision-making with respect to vaccination. Increases in perceived vaccine risk will tend to induce larger declines in vaccine uptake for pathogens that cause more secondary infections (such as measles and pertussis). After a vaccine scare, even if perceived vaccine risk is greatly reduced, it will be relatively difficult to restore prescare vaccine coverage levels.
Footnotes
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↵ ‡ To whom correspondence should be addressed. E-mail: cbauch{at}uoguelph.ca.
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This paper was submitted directly (Track II) to the PNAS office.
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Abbreviation: CSNE, convergently stable Nash equilibrium.
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↵ ¶ Fox, F., MMR Learning Lessons, Meeting hosted by the Science Media Centre at the Royal Institution, London, U.K., May 2, 2002. Available at: www.sciencemediacentre.org/mmr_report.htm.
- Copyright © 2004, The National Academy of Sciences
