spanning over two orders of magnitude, as does the range of potential expenditures.*
The expenditures listed in Tables 9.1 and 9.2 do not represent the net costs of using a vaccine (which may be a cost saving if averted treatment costs outweigh development and vaccination program costs). Hence, they cannot be used in formal cost-benefit or cost-effectiveness analyses. However, they can be used to illustrate how priority rankings may differ if financial resources (mostly needed in the countries of use) become a concern.
The ranking based on health benefits in Table 9.2 would be the initial priority assignment if resource constraints were not a concern. As financial constraints become a concern, the potential health benefit values can be adjusted to reflect the expenditures that might be considered feasible to gain a unit of benefit—in this analysis an infant mortality equivalence unit (IME). At each level of “willingness to pay,” this adjustment represents the health benefit (IME units prevented) that could be obtained by spending an amount of money equivalent to the expenditures on a particular vaccine in a different manner, for example, on another vaccine. This is termed the net opportunity cost of resources. Specifically,
Table 9.3 shows, for the various vaccine candidates, the annualized present values of potential health benefits adjusted for opportunity costs at various levels of willingness to pay per IME averted. Positive values reflect the relative size of benefits for vaccines that are “affordable” at that level of willingness to pay. Negative values apply to vaccines that are not affordable at that level of willingness to pay, that is, the cost of obtaining a unit of health benefit with that particular vaccine exceeds the resources or willingness to pay. It must be emphasized that the values in Table 9.3 reflect the use of expenditures as a measure of affordability rather than net costs, as discussed above. Expenditures on some vaccines may return net cost savings.
Rankings developed from these adjusted values reflect, for each level of willingness to pay, both the size of the potential benefit and its affordability. Table 9.4 shows the rankings of vaccine candidates at various levels of willingness to pay.
If desired, expenditures on vaccine development and use may be incorporated into the ranking process as a decision criterion
Expenditures represent vaccine development cost and vaccine cost (but not delivery, which is assumed uniform) for the vaccination program (see Chapter 4).