Global Issues in Comparing Vaccination Strategies

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Global Issues in Comparing Vaccination Strategies
Dr Lara Wolfson Vaccine Assessment
Monitoring Department of Immunization, Vaccines
Biologicals
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Vaccination Strategies WHO

• Overview of work at WHO
• Examples of current work
• Unmet needs

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Measuring Mortality and Morbidity

• Estimates of current disease burden for
  vaccine-preventable diseases
• Forecasts of future disease burden
  cost-effectiveness under different vaccination
  scenarios
• Methods and Materials to assist ROs and
  countries in estimation and forecasting of
  disease burden, introduction of new vaccines,
  cost-effectiveness assessments
• Support to users of burden of disease data,
  technical assistance for cost-effectiveness

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Estimating (Total) Mortality at WHO
Life tables
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Vaccine-Preventable Diseases 24
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Causes of 4.1 M Child Deaths, 2002
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Proportional Mortality Approaches
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Natural History Approaches
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Looking at all the sources of data
Method 1
Best estimate
Method 3
Method 2
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General Approach

• Get best data/information (literature/grey
  literature review)
• Primary data
• Secondary data
• Seek expert advise/opinion
• natural history of the disease
• methods/models
• context
• Develop consultative process with ROs/countries
• Develop best methods/models
• Use best assumptions/probabilities
• Conduct sensitivity analysis
• Validate/check consistency coherence
• Document (explicit transparent)
• Subject to in-house review, then expert review

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Expected Outputs

• Burden of Disease Estimates
• By country, age group, sex, year
• With estimates of uncertainty, document methods
• Country consultation, continuous update of inputs
  (?!?)
• "Scenarios" (aka Comparing Strategies)
• Recommendations for best practice
• Tools for use at country level
• Provide support to advocacy efforts
• Cost-Effectiveness
• Tools and guidelines, training, support

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Publish methods, database Of results,
inputs Country clearance
HQ produces burden of disease estimates
Simultaneous
Update annually
Develop scenario models And database of inputs
Develop costing tools and guidelines
Publish tools
Country Requests CEA assistance
Targeted Country for Field-testing or Evaluation
Publish tools
IF!
Collaborate with country On CEA
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GAVI and the Vaccine Fund

• 75 out of 192 member states with GNI lt1000
  eligible for support
• Immunization Systems Strengthening (ISS) support
  performance/reward based system
• New Vaccine Support (NVS) vaccine provided for
  1st five years
• "Next Window" 2005-2009
• ICF (Investment Case Framework)

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The ADIP Paradigm
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The Example Measles

• Need to develop a method for estimating measles
  mortality and morbidity
• Measure progress towards Measles Mortality
  Reduction Goal (50 reduction in measles deaths
  from 1999-2005)
• Evaluate the impact of supplemental immunization
  activities (SIAs) and routine coverage
• Develop a tool for countries to use to estimate
  their own disease burden and monitor progress

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"Current" Burden of Measles
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CFR Literature Review
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869,000 in 1999 to 610,000 in 2002
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Measles Comparing Vaccination Strategies in 35
African Countries, 2005-2015
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SIR Model for 192 Member States
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How to calculate R0?
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Looking at Scenarios
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(No Transcript)
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Work that is needed (urgently!!)

• High Priority/Some Work Started
• Pneumococcal Disease (Meningitis, Pneumonia)
• Rotavirus
• Yellow Fever
• Rubella/CRS
• Diphtheria

• Lower Priority/Not Started
• Meningoccocus A/C
• Japanese Encephalitis
• Mumps
• Dengue
• Typhoid
• Cholera
• ETEC
• Papillomavirus
• RSV
• Shigella
• Streptococcus group A
• Infant TB

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CEA
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Data Collected by the Global Monitoring System
(VAM)
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Mixed Bag of Needs

• Simple tools for use in country to make policy
  decisions but validated compared to complex
  methods.
• Valid assessments of current burden of disease
  (MDG!!)
• Guidance on plugging "data holes"
• Introduction of new vaccines