This chapter presents the results obtained from the priority assessment system described in the preceding chapters. Health benefits and net costs have been calculated for each of the 22 vaccine projects,* and the candidates have been ranked accordingly. These rankings reflect assumptions made in the central analysis, presented in Chapters 1 through 7 and reiterated below. To illustrate the use of other assumptions (all considered plausible by the committee), several sets of sensitivity analyses have been performed. These examine the effects on the rankings of different perspectives on the undesirability of morbidity and death, of different discount rates, and of alternative assumptions on the probability of successful development, likely utilization, and vaccine cost.

The rankings discussed below should be used as a guide to the selection of development priorities after consideration of the assumptions and issues outlined in Chapters 3 and 8. The committee believes that one of the major strengths of this analysis is that it encourages those using it to examine all judgments and assumptions involved in the decision process. New data should be incorporated as they become available. Alternative assumptions regarding variables in the model may be incorporated as appropriate, depending on the purposes for which decision makers are using this tool.

The central analysis described below incorporates the following:

1. Vaccine and development characteristics described in Chapter 5, including predictions on the target population, efficacy, and vaccine cost.

2. The anticipated utilization rate estimated for a “no combination, no promotion” situation (Chapter 6).