Economics of influenza vaccine administration timing for children.

The Advisory Committee on Immunization Practices (ACIP) has identified children as a high-risk group for influenza and recommends that children (aged 6 months to 18 years) receive influenza vaccine each year.1,2 The 2009 influenza A(H1N1) (H1N1) pandemic highlights the importance of the timing of influenza vaccination as decision makers have endeavored to get vaccines to priority groups as soon as possible. While the presumption is that earlier vaccination is better so that a child is protected for a greater proportion of the influenza season, studies to date have not quantified how the economic value of vaccination may change with the timing of vaccine administration. Moreover, it is unclear how late in the influenza season vaccination still should be offered. Quantifying how the vaccine's economic value changes with the timing of vaccination may be important for vaccine production, distribution, and administration planning. The 2009 H1N1 pandemic demonstrated the feasibility of manufacturing, delivering, and administering seasonal influenza vaccine by September or October.3 Manufacturers and the supply chain were able to expeditiously produce and distribute seasonal influenza vaccine, despite manufacturing H1N1 influenza vaccine concurrently.4–6 In fact, studies6,7 have shown that in past years more than 70% of seasonal influenza vaccines have been available for administration by October. With evidence suggesting that earlier vaccination is possible, the next question is how much should be invested to ensure timely vaccination? The answer to this question depends in large part on the economic effect of delaying vaccination. Investment could occur all along the supply chain, from the very beginning (eg, investing to expand vaccine production capacity or to use antigen-sparing technology) to the very end (eg, investing to improve access to immunization clinics, school-based programs, health fairs, and healthcare provider visits). To address these issues, we constructed the following 2 sets of computer simulation models for children aged 2 to 18 years: (1) the children's influenza vaccination timing model, to quantify the incremental economic value of vaccinating a child earlier in the influenza season and the incremental cost of delaying vaccination, and (2) the children's monthly influenza vaccination decision model, to determine the cost-effectiveness of vaccinating versus not vaccinating a child for every month of the influenza season.