Effectiveness and cost-effectiveness of expanded antiviral prophylaxis and adjuvanted vaccination strategies for an influenza A (H5N1) pandemic.
BACKGROUND
The pandemic potential of influenza A (H5N1) virus is a prominent public health concern of the 21st century.


OBJECTIVE
To estimate the effectiveness and cost-effectiveness of alternative pandemic (H5N1) mitigation and response strategies.


METHODS
Compartmental epidemic model in conjunction with a Markov model of disease progression.


METHODS
Literature and expert opinion.


METHODS
Residents of a U.S. metropolitan city with a population of 8.3 million.


METHODS
Lifetime.


CONCLUSIONS
Societal.


METHODS
3 scenarios: 1) vaccination and antiviral pharmacotherapy in quantities similar to those currently available in the U.S. stockpile (stockpiled strategy), 2) stockpiled strategy but with expanded distribution of antiviral agents (expanded prophylaxis strategy), and 3) stockpiled strategy but with adjuvanted vaccine (expanded vaccination strategy). All scenarios assumed standard nonpharmaceutical interventions.


METHODS
Infections and deaths averted, costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness.


RESULTS
Expanded vaccination was the most effective and cost-effective of the 3 strategies, averting 68% of infections and deaths and gaining 404 030 QALYs at $10 844 per QALY gained relative to the stockpiled strategy.


RESULTS
Expanded vaccination remained incrementally cost-effective over a wide range of assumptions.


CONCLUSIONS
The model assumed homogenous mixing of cases and contacts; heterogeneous mixing would result in faster initial spread, followed by slower spread. We did not model interventions for children or older adults; the model is not designed to target interventions to specific groups.


CONCLUSIONS
Expanded adjuvanted vaccination is an effective and cost-effective mitigation strategy for an influenza A (H5N1) pandemic. Expanded antiviral prophylaxis can help delay the pandemic while additional strategies are implemented.


BACKGROUND
National Institutes of Health and Agency for Healthcare Research and Quality.
Khazeni
Nayer
N
Division of Pulmonary and Critical Care Medicine, Stanford University Medical Center, 300 Pasteur Drive, H3143, Stanford, CA 94305, USA.
Hutton
David W
DW
Garber
Alan M
AM
Owens
Douglas K
DK
D000276:Adjuvants, Immunologic / Q000191:economics*; D000367:Age Factors; D000998:Antiviral Agents / Q000627:therapeutic use; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D004196:Disease Outbreaks / Q000191:economics / Q000517:prevention & control*; D005260:Female; D006801:Humans; D017589:Immunization Programs; D053124:Influenza A Virus, H5N1 Subtype; D007252:Influenza Vaccines / Q000009:adverse effects / Q000191:economics* / Q000600:supply & distribution; D007251:Influenza, Human / Q000191:economics / Q000453:epidemiology / Q000517:prevention & control*; D008297:Male; D008390:Markov Chains; D032541:Mass Vaccination / Q000191:economics*; D019057:Quality-Adjusted Life Years; D012680:Sensitivity and Specificity; D014481:United States / Q000453:epidemiology
D000276:Adjuvants, Immunologic; D000998:Antiviral Agents; D007252:Influenza Vaccines