Date and Time
June 4, 2008
1:30 PM - 3:00 PM

Availability
Open to the public
No RSVP required

Speaker
Nayer Khazeni

Background: The pandemic potential of the influenza A H5N1 virus is one of the primary international public health concerns of the 21st century. Although expenditures for influenza preparedness have reached $6 billion in the United States, the effectiveness and cost effectiveness of alternative public health strategies to reduce mortality and morbidity from pandemic influenza are not known.

Methods: We developed a dynamic transmission model of pandemic influenza A H5N1 in a large U.S. metropolitan city. We compared societal costs and benefits of antiviral prophylaxis and adjuvanted prime-boost vaccination (in which a pre-pandemic vaccine with high immunogenicity is followed by a booster once the pandemic begins) with a limited vaccine/prophylaxis strategy based on the vaccine and antiviral components of the U.S. Health and Human Services pandemic plans. We measured outcomes in costs, infections and deaths averted, quality-adjusted life-years (QALYs), and incremental cost-effectiveness. We estimated transmissibility, morbidity and mortality of pandemic Influenza A H5N1 from the literature. We estimated effectiveness of interventions from the literature and expert opinions of influenza researchers. We estimated costs from the literature and expert opinions of public health and hospital officials. We tested all parameter assumptions in sensitivity analyses.

Results: Adjuvanted Prime-Boost Vaccine prophylaxis was the most effective and most cost-effective strategy, averting 33% of infections and 33% of deaths at an incremental cost-effectiveness ratio of 6,864 USD/QALY compared to the Limited Vaccine/Prophylaxis Strategy. The Limited Vaccine/Prophylaxis Strategy averted 4% of infections and 4% of deaths as compared with no intervention. The Antiviral Prophylaxis Strategy was effective only for its limited duration of use; it averted 4% of infections and 4% of deaths as compared with the Limited Vaccine/Prophylaxis Strategy, and its cost-effectiveness was dominated by the Vaccination Strategy.

Conclusions: Adjuvanted prime-boost vaccination is an effective and cost-effective preventive strategy for an influenza A H5N1 pandemic. Antiviral prophylaxis has modest epidemiological benefits, but can be beneficial in delaying the pandemic while additional strategies are implemented.