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Workshop on Analyzing the Polio Eradication Endgame

  • FHCRC 1100 Fairview Ave North Seattle, WA (map)

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The MIDAS Center for Inference and Dynamics of Infectious Diseases (CIDID) is sponsoring a workshop on July 1 and half of 2, 2015, in Seattle, Washington, USA that will include major groups modeling polio transmission and others involved with the polio eradication endgame.  The workshop will focus on how the complete eradication of wild poliovirus (WPV) and of circulating vaccine derived poliovirus (cVDPV) can be adequately assured when oral polio vaccine (OPV) use is stopped.  In particular, the workshop will focus on the issue of silent circulation (i.e., viral transmission in the absence of detected paralytic cases), which can involve a high number of asymptomatic infections, even in the context of high coverage with inactivated polio vaccine (IPV), as demonstrated in 2013-4 in Israel.  

The detection of WPV or cVDPV silent circulation is possible with environmental surveillance at some expense.  The high cost makes it currently infeasible to ensure a low probability of silent circulation using just data from worldwide sampling.  The sampling will likely need to be focused on those areas with the highest probability of silent circulation.  As the time since the last paralytic poliomyelitis case increases, the probability of silent circulation decreases.  But model analyses show that different conformations of poliovirus transmission systems can have markedly different rates of decrease.  Some theoretically possible systems could sustain silent circulation for many years even when the level of OPV vaccination that achieved elimination of polio cases is sustained.  More theoretical and empirical work on silent circulation is needed to identify the characteristics of transmission systems that make silent circulation possible.  That work will be advanced by better estimates of polio transmission system parameters affecting the possibility of silent circulation.  This workshop will focus on identifying the theoretical modeling work, field studies, data collection, and the data analysis methods most likely to improve the choice of locations and methods for detecting silent circulation.

The four existing active polio modeling groups take different approaches to polio modeling and making inferences about programmatic choices.  This diversity should provide strength.  To ensure that it does, each group could help strengthen the work of the other groups.  That will require the open dialogue and a potential for collaborative modeling and data analysis research that this workshop seeks to promote.  Each modeling group will present what their approach can say about the potential for silent circulation and what data or theory development might best help focus silent circulation detection efforts on the methods and places with the highest chances for detecting silent circulation.  Individuals involved in global polio eradication initiative laboratory or fieldwork efforts or policy formation related to silent circulation participating in this workshop will provide input in guiding the policy issues on which modelers can most productively focus. This interaction between modelers and policy makers is essential for modelers to make the most informative data analyses and policy choice projections.


This agenda is meant to promote discussion and can be made flexible to pursue the discussion directions that seem most important. It takes a diverse community of scientists, modelers, and people who can influence policy to understand any complex system in medicine or public health. We hope the discussions in this workshop will be a step in community building that will help insure polio eradication is achieved soon and solidly. Because the polio transmission system is so complex and because the consequences of failing to understand the phase transitions that must be passed through to achieve eradication are so severe, our dialogue could make an essential contribution to understanding what could happen during the endgame and how we should be prepared for whatever might come.

July 1: morning

8:00-8:05  |  Welcome : Betz Halloran

8:05-8:20  |  Introductions

What are the most important endgame issues to be modeled, the most important parameters or relationships to be estimated, and the most important policy guidance to be provided?  (Online material including the presentation and things that might come up in discussion to be provided one week before the workshop.)

8:20-8:25  |   WHO research unit perspective

8:25-8:30  |   Environmental surveillance perspective

8:30-8:35  |   Global Polio Laboratory Network perspective

8:35-8:40  |   Gates Foundation perspective

8:40-8:45  |   Imperial college perspective

8:45-8:50  |   Kid Risk perspective

8:50-8:55  |   Institute for Disease Modeling perspective

8:55-9:00  |   CIDID perspective

9:00-9:50  |    Discussion

9:50-10:20  |   Break

What are the implications of work by each modeling group with regard to how silent circulation could affect the polio eradication endgame?  

10:20-12:00  |  10 minute Presentations by each of the four modeling groups with 15 minute discussions.  (Online material including the presentation and things that might come up in discussion to be provided one week before the workshop.)

July 1: afternoon

Approaches to modeling, parameter estimation, and policy guidance during the endgame: This afternoon focuses on the logic of how models inform policy decisions and the methodology for constructing and analyzing models that inform policy.  Each group is to  illustrate their approach to making inferences that can guide endgame policy with a discussion of the overall philosophy of modeling used by the group and its advantages and disadvantages.

1:00-2:20  |  20 minute presentations with 20 minutes of discussion for two groups

2:20-2:50  |  Break

2:50-4:10  |  20 minute presentations with 20 minutes of discussion for two groups

4:10-5:00  |  Open discussion on how the different approaches taken could be made more complementary and informative

6:00  |   Group Dinner (off-campus)

July 2: morning

Data availability, data collection priorities, data analysis methods and inference processes: Any presentations on any of these topics that any group wishes to make will be woven into the discussion format.  Material for presentation and discussion should be supplied one week before the workshop.

8:00–9:40  |  Discussion of what data the different groups have, the value that could be extracted from the data if it were more widely available to the scientific community, and what it would take to make this data more available.  

9:40-10:10  |  Break

10:10-12:00  |  Discussion of modeling priorities, data collection priorities, and coordination between modeling groups and policy people to insure good decisions during the endgame.


Registration has closed.


Sze Conference rooms, Thomas Building, Fred Hutchinson Cancer Research Center campus.


Other modeling groups who would like to participate in this workshop should contact Jim Koopman at


Workshop Organizing Committee

  • Jim Koopman, U Michigan 
  • David Hutton, U Michigan 
  • Marisa Eisenberg, U Michigan 
  • Katia Koelle, Duke U  (did not attend)

Bill and Melinda Gates Foundation/Seattle

  • Ananda Bandyopadhyay
  • Jay Wenger


  • Ben Lopman
  • Steve Wassilak

CIDID Policy Studies/U Michigan

  • Chris Henry
  • Ed Ionides
  • Joonha Park

CIDID/Emory University

  • Rustom Antia

CIDID/Fred Hutch

  • Rebecca Allen, CIDID Project Coordinator
  • Charles Cheung
  • Stephanie Shadbolt, CIDID Associate Director
  • Jonathon Sugimoto

Fred Hutch

  • Alvason Zenhua Li

Imperial College/UK

  • Isobel Blake
  • Kathleen O'Reilly

Workshop Facilitator

  • M. Elizabeth Halloran/CIDID Director, Fred Hutch and U Washington


Institute for Disease Modeling Bellevue 

  • Mike Famulare
  • Hil Lyons
  • Kevin McCarthy

Kid Risk, Inc./Orlando

  • Kimberly Thompson
  • Radboud Duintjer Tebbens


  • Colleen Burgess

University of Maryland

  • Philip Johnson

University of Michigan

  • Joe Eisenberg (did not attend)

University of Minnesota

  • Nicole Basta

Tel Aviv University/Israel

  • Lester Shulman


  • Ondrej Mach



General materials can be viewed here.

Participant materials can be viewed here. (password required)