daily among infants and children, combination products have the advantage of reducing the number of separate vaccine doses that must be administered, which can aid efforts to achieve desired levels of vaccine utilization. Including combination vaccines in the analysis is not difficult in principle, but would add to the burden of assessing expert judgment on utilization, costs, and effectiveness of the vaccines if available in combination forms. Many vaccine combinations might be possible, and the committee had no basis for selecting any specific combinations as more or less likely. Therefore, combination products were not included in the analysis.

The committee was originally asked to include in its analysis the contraceptive vaccines that are in development. Although the scientific foundation for research and development of a contraceptive vaccine is clear and such vaccines are being studied and can be expected to provide a needed addition to the array of contraceptive options that are currently available, an analysis of their anticipated cost-effectiveness within the framework adopted for this study poses particularly difficult ethical and philosophical problems that the committee felt unqualified to address.

Trying to measure the health benefits produced by a contraceptive vaccine would require a determination of whose health is affected by an unintended pregnancy (the mother’s health, the child’s health, or the health of others in the family), what those effects are (psychological distress or a normal life expectancy), and how long they last. For the most part, the benefits of contraceptive vaccines are not health-related but relate instead to the economic and psychological well-being of the mother. Therefore, societal priorities for such vaccines should be based on a broader concept of benefit than quality-adjusted life years. For the other vaccines in the study, there is little question that the prevention or treatment of an illness is a desirable outcome. For a contraceptive vaccine, however, it is not clear whether prevention of a pregnancy can always be viewed as completely desirable. For a woman who does not wish to become pregnant, the outcome can be considered positive, but a concern is how to assess the health effects that result if a contraceptive vaccine prevents a desired pregnancy. Questions also arise regarding the costs to be considered in the analysis. For example, should the vaccine be credited with saving the cost of raising a child or with having prevented the productivity of that child? Until a clearer consensus is established regarding the answers to questions such as these, it seems inappropriate to include a contraceptive vaccine in a cost-effectiveness model.