Seasonal Influenza Vaccination Update and the Business Case for Vaccination, 200607

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Seasonal Influenza Vaccination Update and the
Business Case for Vaccination, 2006-07

• Raymond A. Strikas, MD
• National Vaccine Program Office
• Department of Health and Human Services
• September 12, 2006

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Outline

• Updates to the Annual Influenza Prevention and
  Control Recommendations
• The Business Case for Influenza Vaccination
• Supply Update
• of doses
• timing
• Key Strategies
• Contingency planning
• Distribution data for public health
• Efforts to increase vaccine use

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Updates to the Annual Influenza Prevention and
Control Recommendations

• Annual vaccination of healthy children aged
  24--59 months and their household contacts and
  out-of-home caregivers
• Emphasis on need for two doses of vaccine (live
  or inactivated) in all children aged 6 months--lt9
  years who have not been previously vaccinated at
  any time

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Updates to the Annual Influenza Prevention and
Control Recommendations

• Emphasis on continuing to offer vaccine
  throughout the influenza season, even after
  influenza activity has been documented in a
  community
• Avoid use of amantadine and rimantadine for the
  treatment or chemoprophylaxis of influenza A
  because of recent data indicating widespread
  resistance of influenza virus to these
  medications

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Updates to the Annual Influenza Prevention and
Control Recommendations

• Viral strains for the 2006--07 trivalent vaccine
  virus strains
• A/New Caledonia/20/1999 (H1N1)-like
• A/Wisconsin/67/2005 (H3N2)-like
• B/Malaysia/2506/2004-like antigens
• For the A/Wisconsin/67/2005 (H3N2)-like antigen,
  manufacturers may use the antigenically
  equivalent A/Hiroshima/52/2005 virus for the
  B/Malaysia/2506/2004-like antigen, manufacturers
  may use the antigenically equivalent
  B/Ohio/1/2005 virus.
• http//www.cdc.gov/mmwr/preview/mmwrhtml/rr5510a1.
  htm

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Estimated Size of ACIP Recommended Groups
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The Business Case for Influenza Vaccination
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Example of Potential Costs For Inclusion in
Economic Models Evaluating Influenza Vaccination
DIRECT
INDIRECT
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Challenges In Study Of Economics Of Influenza
Disease And Interventions

• Hallmark of influenza is variability over time,
  e.g.
• Burden of disease
• Effectiveness of vaccination
• Non-specificity of commonly used outcomes
• e.g. modeling of influenza-related
  hospitalizations doesnt allow influenza-specific
  hospitalization cost estimate

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Influenza-Associated Hospitalizations By Age
Group (Thompson et al, JAMA, 2004)
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Influenza Illness Rates Over Time

• Can vary widely from year to year
• Limited longitudinal data laboratory confirmed
  influenza
• Most studies 1-5 years in length
• Combining studies challenging based on wide range
  of outcome measures

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Average influenza-associated illness rates by age
group
Low estimate based on Tecumseh community
studies. High estimate based on Houston family
studies. Adapted from Sullivan KM.
PharmacoEconomics 19969 Suppl.326-33.
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Annual Influenza Infection Versus Illness Rates

• Not all infections result in illness or cost
• Estimate infections causing symptoms
• e.g. 33-65 in studies by Edwards, JID Keitel,
  Vaccine and Bridges, JAMA studies among adults

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Influenza Versus Less Specific Outcomes

• Influenza-like illness outcome
• Defined in many different ways, e.g.
• fever plus cough or sore throat
• fever with 2 or more respiratory symptoms
• Dampens measurable benefit of intervention
• Cannot mix outcomes in economic models, e.g. ILI
  attack rate and laboratory confirmed influenza
  vaccine effectiveness
• Relative proportion of ILI due to influenza
  variable

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Vaccine effectiveness

• Varies by age group, risk group, and year
• Variety of outcomes in literature
• May be low when suboptimal antigenic match
• Variability and risk of either low levels
  influenza activity and/or poor match need to be
  considered in models
• e.g., despite good match, VE zero with low
  illness rate, Hoberman, et al 2003
• Only 1 randomized trial in older adults
• Herd immunity effects may also be considered

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Inactivated Vaccine Effectiveness by Age and Risk
Group
Overall range from studies conducted when good
antigenic match between vaccine and circulating
strains. Effectiveness may be zero when vaccine
and circulating strains antigenically different.
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Comparison Different Outcomes And VE Estimated
For Three RCT In Adults
Not statistically significant
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Indirect Cost Productivity Costs for Lost Work
Days

• Costs due to lost time from work or school can
  account for large proportion of total costs and
  benefits of vaccination programs
• E.g. 70-90 of healthy adult influenza economic
  burden
• Propensity to take time from work/school may vary
  by culture and population

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Example Indirect Cost Variability by Region

• Average number missed work days per
  influenza-like illness
• Kumpulainen 1997 4.9 days (Finland)
• Keech 1998 2.8 days (UK)
• Carrat 2000 1.6 (France)
• Nichol 1996 0.7-.9 days (US)
• Bridges 2000 0.6-1.0 days (US)
• Fitzner 2001 0.06 days (Hong Kong)

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Estimation of direct costs

• Cost of outpatient illnesses
• Data more robust than other outcomes
• Costs of hospitalizations
• Rates of hospitalization based on administration
  databases
• Proportion of those due to influenza by diagnosis
  unclear
• Valuation of costs from case series of laboratory
  confirmed influenza helpful

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Selected Vaccination Cost Analyses Results
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Summary of Business Case for Influenza Vaccination

• Both live and inactivated vaccines are effective
  in preventing influenza-related illness
• Cost-effectiveness will vary with severity of
  annual outbreak, vaccine match and effectiveness,
  and population vaccinated
• Vaccination is usually cost-effective and may be
  cost-saving for an employer
• Offering vaccination at the workplace improves
  vaccination uptake

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Projected Production
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Cumulative Monthly Influenza Vaccine Distribution
Doses (Millions)
100 (projected)
81.2
83
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Supply Limitations for Young Children

• CDC anticipates that providers may be unable to
  obtain sufficient vaccine for their 3 year old
  patients
• Single supplier of vaccine for this age-group
• Timing of expanded recommendation (occurred after
  pre-booking period)
• For providers without sufficient vaccine for all
  6-59 month olds, CDC recommends providers
  consider prioritizing 6-23 months olds.

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ACIP Priority Groups for Influenza Vaccination,
2006-07
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Balancing Supply and Demand/Utilization

• We must have contingency plans in place in the
  event that vaccine is delayed or the supply is
  insufficient.
• We want to promote influenza vaccine utilization
  to optimize health protection of the US
  population and minimize waste of vaccine.
• Sometimes work done to address one of these
  goals may seem to contradict the other goal.

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June 22, 2006 The Second 2006 Meeting of the
National Influenza Vaccine Summit

• Objective Discuss, develop, and implement a plan
  to increase utilization of influenza vaccine for
  the 2006-07 season
• Focus
• Vaccination of priority groups, contacts, and the
  general public
• Helping health care providers to better promote
  influenza vaccination
• Communication strategies to facilitate increased
  utilization of influenza vaccine

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Meeting Outcomes

• Six teams identified to develop plans for the
  short-term goal of increasing utilization for
  this upcoming season
• Targeting Healthcare Workers  
• Targeting children aged 6 mos. through 18 years  
• All Contacts of High-Priority Populations with an
  eye towards Universal" (focus on three groups)
• Persons in the workforce
• College students
• Faith-based
• Extending the Vaccination Season  
• Unifying/Creating Provider Toolkit  
• Utilizing Partnerships (to improve education,
  reduce barriers for immunizing, and sharing
  fiscal risk of influenza vaccine)