Lessons From the Polio Endgame: Overcoming the Failure to Vaccinate and the Role of Subpopulations in Maintaining Transmission
by Kimberly M. Thompson and Radboud J. Duintjer Tebbens, Journal of Infectious Diseases 2017;216(S1):S176-S182, doi:10.1093/infdis/jix108.

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

What are the study’s main findings?

• The study uses a hypothetical transmission model with different assumptions to illustrate how an under-vaccinated subpopulation can sustain transmission despite high coverage in the surrounding population.
• Modeling and experience suggest that the failure to immunize under-vaccinated subpopulations represents a root cause of polio endgame challenges related to: (i) interrupting wild poliovirus (WPV) transmission in last endemic countries, (ii) preventing WPV importation outbreaks, and (iii) preventing or stopping the emergences of circulating vaccine-derived poliovirus serotype 2 (cVDPV2) likely to occur in the same security-compromised areas that also sustain WPV transmission.
• In some cases, serotype-specific use of oral poliovirus vaccine (OPV) created under-vaccinated subpopulations for other serotypes.
• Reaching under-vaccinated subpopulations with vaccine represents the key for a successful polio endgame, but maintaining sufficient population immunity to transmission everywhere remains a prerequisite.
• After cessation of OPV use, immunodeficient patients that may become prolonged or chronic poliovirus excretors represent a particular subpopulation that requires focused risk management.
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• Future eradication initiatives should learn important lessons from the polio eradication experience and create performance expectations for countries to identify and reach all people living within their borders with maintained high coverage with appropriate interventions.
• The global capacity created by the Global Polio Eradication Initiative (GPEI) to manage the risks related to key subpopulations currently represents a critical global resource for polio and other infectious diseases, and the study recommends maintaining this type of global capacity beyond the existence of the GPEI.
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