order to realize health benefits. These procedures are described and illustrated in the first volume of the committee’s report [Institute of Medicine, 1985].)

The approach described in this report is recommended by the committee for the selection of priorities for accelerated development of vaccines against diseases prevalent in developing countries because it separately identifies each logical component of potential benefits and potential expenditures associated with individual vaccine contenders. The analysis distinguishes quantifiable consequences from the probability they will occur and also incorporates information on when the consequences are likely to occur. In addition, the approach requires that an effort be made to state the sources and reasons for all assumptions and estimates. The committee suggests that the potential global health benefits of a vaccine take precedence in determining its initial ranking for accelerated development. The affordability of the benefits, as represented by the relevant expenditures on vaccines, should also be considered along with other nonquantifiable considerations (discussed in Chapter 8) in the final selection of priority projects.

The committee does not attempt to place a monetary value on health benefits, to suggest how many vaccines are worthy of development, to compare investment in basic scientific research with investment in accelerated vaccine development, or to anticipate the source of funds for any vaccine-related programs.

The approach adopts a perspective for the developing world as a whole on health benefits and expenditures. This does not imply that the priorities that emerge from this analysis are necessarily those that should be adopted in all circumstances. The methods used in this analysis (and additional procedures used to estimate differences in vaccine utilization and cost savings from treatment averted) can be applied by others for determining priorities for specific countries or regions.

The selection of candidates for accelerated vaccine development should be an ongoing process. One of the benefits of the model is that it provides a structured format in which to incorporate new research findings. This is especially important, given the rapid development of new techniques in biotechnology.

After the annualized expenditures and the annualized potential health benefits have been determined for each vaccine candidate, the results must be interpreted based on the type of constraints that limit the number of candidates that may be selected. Specific procedures exist for incorporating affordability (willingness to pay) into the rankings based on health benefits or for using expenditures as a decision criterion equal to health benefits. If ranking or dominance considerations alone do not provide a complete slate of candidates, decision makers must make judgments on the basis of various other