will make the point most clearly. Suppose group A patients have a serious disease that leaves them with a health utility level of .25 as measured by the HUI, and their HUI level would be raised only to .45 with the best available treatment because no treatment is very effective for their disease. A similar number of group B patients have a health utility level of .60 because they have a considerably less serious disease, but since treatment for their disease is more effective although no more costly than for Group A patients, it would raise their health utility to .90. Suppose we only have funds to treat one of these groups. Should we prefer to treat B because doing so would produce a 50% greater benefit than treating A (an increase in HUI of .3 for group B compared to an increase in HUI of .2 for group A) or should we give priority to treating group A who are sicker or worse-off?
There is some empirical evidence that when asked about choices like this, most persons, both in this country and elsewhere, would prefer to treat the sickest or worst-off in our example group A, even at the cost of a significant reduction in overall benefits, compared with treating the less sick or better off, that is group B. This may be because they view doing so as fairer or more just. Justice or fairness may favor preferring first to help group A who suffer from the worse or greater disadvantage; to treat group B instead would only widen the already undeserved difference in the levels of well-being between A and B. If group A is treated, their level of well-being after successful treatment (.45) will still be below that of B even if that group receives no treatment (.60). Some people would prefer to treat group A over group B because they believe that treatment would be subjectively more important for persons in group A, despite the greater measured benefit that could be produced for B.
Although setting priorities among potential vaccines does not involve choices about treatments of different diseases, but rather choices between different diseases that might be prevented, the committee believes essentially the same issue is at stake. The issue is what priority, if any, should be given to patients who would be the sickest if their disease is not prevented—for example, preventing opportunistic infections such as cryptosporidiosis in patients with AIDS whose health status will remain low because of their AIDS—compared to greater health benefits that could be produced by preventing generally less serious diseases like mumps or chicken pox in patients without AIDS or other serious predisposing conditions.
Part of the complexity of this issue is that virtually no one would prefer not to treat the sickest, no matter how costly their treatment and how small the benefit to them from doing so, and no matter how beneficial and how inexpensive the treatment for the less sick. If fairness or equity is what is at stake here, there is a limit to how much gain in the well-being of others we will sacrifice in order to treat all fairly or equitably by giving priority to those with the most serious diseases. However, there does not seem to be any objective, principled basis for determining how much gain in overall well-being should be sacrificed in order to treat the sickest or, more generally, to avoid different forms or instances of unfairness. Here again, there is no consensus among ordinary persons, bioethi-