. "3. Overview of the Analytic Approach." New Vaccine Development: Establishing Priorities: Volume II, Diseases of Importance in Developing Countries. Washington, DC: The National Academies Press, 1986.
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New Vaccine Development: Establishing Priorities, Volume II, Diseases of Importance in Developing Countries
where symbols are defined as in Equation 1 and
B
=
expected annual steady-state benefits from vaccine, adjusted for efficacy (E) and differential utilization (U), if necessary; and
SE
=
expected annual incidence of vaccine side effects.
In this analysis, it is assumed that differential utilization will not be a factor in determining the potential health benefits achievable with vaccine candidates (all are assumed delivered through WHO-EPI) and, as discussed in Chapter 7, side effects are judged to be negligible. Thus, in this analysis the expression for relative benefits simplifies to
(4)
where
B’
=
expected annual steady-state benefits from vaccine, adjusted for efficacy but not adjusted for utilization (it thus represents relative potential benefits).
Figure 3.1 summarizes the hierarchy of components that would make up a comprehensive analysis of the expected health benefits and expected costs for each prospective vaccine. Figure 3.2 shows the components assessed in the simplified analysis judged appropriate for the purposes of the exercise described in this report. Each element of benefit and of cost is based on estimates related to the target disease or to the subject vaccine. Implementation of the comprehensive approach shown in Figure 3.1 for vaccines for diseases of importance in the United States is described in the committee’s first report (Institute of Medicine, 1985). Chapter 7 of this report describes the implementation of the comparison scheme shown in Figure 3.2. The scheme integrates the components of benefit and cost separately, adjusts each for the probability that it will occur and for the expected delay until realization, and presents the conclusions of a central analysis.
INTERPRETATION OF RESULTS
The interpretation of results from implementation of the comprehensive approach to the analysis (Figure 3.1)—which develops annualized net expected costs and annualized expected health benefits for each candidate vaccine—is discussed in the committee’s first report (Chapter 3, Institute of Medicine, 1985). The description below illustrates procedures for the interpretation of the results of the simplified analysis shown in Figure 3.2.
