The Case for Cooperation in Managing and Maintaining the End of Poliomyelitis: Stockpile Needs and Coordinated OPV Cessation
by Kimberly M. Thompson and Radboud J. Duintjer Tebbens, The Medscape Journal of Medicine 2008;10(8):190 (August 13, 2008). Available at: PDF

Answers to frequently asked questions

What are the study’s main findings?
What are the study’s main recommendations?
Background on polio

What are the study’s main findings?

  • Risk analysis and game theoretical modeling suggests that successful poliovirus risk management after eradication requires global coordination of OPV cessation and cooperation on a global polio vaccine stockpile.
  • We previously estimated a probability ranging from 50% to 100% of at least one outbreak somewhere in the world after coordinated OPV cessation. However, individual countries face much smaller probabilities of outbreaks (see Table 1 in the paper), which may influence their perceptions of risks.
  • Continued use of OPV after eradication of wild polioviruses represents a bad option, both in terms of costs and cases. Countries that wish to continue OPV vaccination beyond the future recommended time of coordinated OPV cessation (T0) not only risk creating circulating vaccine-derived poliovirus (cVDPV) outbreaks within their own borders, but also pose serious risks of exporting live polioviruses to countries that no longer use OPV.
  • Despite the perceived costs and risks of continued OPV vaccination, countries that stop vaccination before T0 put themselves at a very high risk of outbreaks due to imported OPV viruses. Countries that are currently using OPV should continue to do so or switch to IPV with the highest possible coverage, at least until global coordination of OPV cessation.
  • Given the financial and health costs associated with either stopping before or after T0, a simple game theoretical model shows that coordinated cessation of routine OPV is both globally optimal and optimal for individual countries.
  • Given the uncertainty of where and when outbreaks will happen after eradication, lack of a global vaccine stockpile would mean that each country would have to establish and maintain its own national stockpile. A global stockpile of a reasonable size (see Figure and accompanying text in the paper) would offer a more efficient alternative by pooling resources and providing insurance to all countries.
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What are the study’s main recommendations?
  • If the world health leaders decide in favor of OPV cessation after interruption of wild poliovirus transmission, then global negotiations should occur to ensure that every country stops OPV use at the same time.
  • This study validates the WHO's current and planned progress towards financing and ensuring universal and rapid access to a global polio vaccine stockpile.
  • Additional research is needed to optimize the design of the stockpile and to develop strategies for using its content in the event of an outbreak after OPV cessation.
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