NVAC Influenza Vaccine Recommendations and Strategies Subgroup

Members: Jerome Klein (Chair), Jeff Davis,Jon Abramson, Carolyn Bridges, Nancy Cox,Ben Schwartz, Jane Seward, David Shay, Lone Simonsen,

Subgroup Objectives

Examine data on influenza disease burden and vaccination program impacts

Determine whether current surveillance provides adequate data to monitor burden & impact

Suggest strategies to improve surveillance Consider potential alternate influenza

vaccination strategies and identify critical issues that NVAC can address as they are being evaluated

Estimating Influenza Disease Burden

Challenges Annual variation in disease No pathognomonic syndrome and infrequent

etiological diagnosis May present without respiratory symptoms and

may contribute to exacerbations of non-respiratory illnesses (e.g., CHF)

Modeled disease burden estimates ~36,000 respiratory and circulatory deaths per

year

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Excess P&I Mortality per 100,000 pop

Influenza season during 1968-1999, US

Trends in Pneumonia & Influenza (P&I)Mortality and Influenza Vaccine Coverage

Simonsen, unpublished data

Unadjusted data, age 65+

Excess All-Cause Mortality, 1969-1999, “Young Elderly”

65-74 yearsP&I

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Excess P&I and All-Cause Mortality, 1969-1999, “Older Elderly”

85+ P&I

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Caveats and Conclusions Caveats

Ecological data are inconsistent with case-control and cohort studies showing significant impacts of influenza vaccine on hospitalization and death

Conclusions A substantial number of influenza associated

deaths occur despite the vaccination program Influenza vaccine effectiveness is lower in the

elderly compared with younger persons Vaccination coverage in the elderly has not

increased in recent years

U.S. Influenza Surveillance: Objectives and Systems

Objective System

Identify strains causing illness

Public health and hospital lab networks test clinical specimens

Monitor morbidity nationally and by state

Sentinel provider network – rates of influenza-like illness

State/territorial epidemiologist reports

Monitor national P&I mortality

122 city death certificate review for P&I as cause of death

Identify cases/outbreaks for investigation

Reports to CDC from health departments and hospitals

U.S. Influenza Surveillance: Gaps

No data on rates of influenza disease or death

No routine monitoring of vaccine effectiveness

Recent and Proposed Enhancements to Influenza Surveillance

New Vaccine Surveillance Network Population-based surveillance for influenza

hospitalization in children <5 y.o. in 3 metro areas Prospective, sensitive diagnostic testing on all

children admitted with febrile or respiratory illness Emerging Infection Program Sites

Identify positive influenza diagnostic tests in children from 10-population based surveillance sites

National reporting for influenza deaths in children (proposed to CSTE)

CDC RFA for annual influenza VE studies

Subgroup Recommendations: Disease Burden, Program Monitoring & Impact

Expand active, prospective surveillance with etiological diagnosis in sentinel populations of children and adults

Collaborate with health care organizations to obtain rapid turn-around data on ILI and documented influenza for VE studies

Meet to evaluate different methods of estimating program impacts; propose studies, as needed, to resolve differences

Provide support for expanded surveillance activities

New Influenza Vaccination Strategies

Subgroup supports ACIP evaluation of expanded (universal?) influenza vaccination

Potential NVAC roles Assessment of vaccine supply issues Assessment of vaccine delivery strategies

(e.g., in schools) and delivery technologies (e.g., intranasal, patch)

Assessment of vaccine financing options Assessment of universal vaccination programs

in other areas (e.g., Ontario, Canada)