HUMAN-BEHAVIOR, COST-EFFECTIVENESS ANALYSIS AND RESEARCH-AND-DEVELOPMENT PRIORITIES - THE CASE OF A SCHISTOSOMIASIS VACCINE

Cost-effectiveness analysis has been widely used in the health sector to guide decisions about where scarce resources aimed at disease preve ntion or control should be invested. It has rarely been used to guide decisions about what type of health research should be funded. In addi tion, the validity of the behavioural assumptions underlying the econo mic analysis is rarely considered explicitly. This paper explores the use of cost-effectiveness analysis to set priorities for research usin g the development of a schistosomiasis vaccine as an example. It then explicitly considers behavioural factors which might affect the accura cy of the calculations. A 'product profile' for the new technology is derived which can be used by developers as a target to aim at. To ensu re that the vaccine would be more cost-effective than the currently pr eferred option for the control of schistosomiasis, chemotherapy based on praziquantel, researchers need a vaccine which has sufficient durat ion of protection to be delivered as part of the regular childhood imm unization programme me. The cost of adding it to existing vaccination schedules should not be more than US$(4.30) per child in excess of the cost of one round of chemotherapy. It should, ideally, have an effica cy over 80%. These results, however, depend on a number of cultural an d behavioural factors which are often ignored in cost-effectiveness st udies. For example, low rates of school attendance would increase the cost of contacting children for a chemotherapy programme and increase the relative attractiveness of a vaccine. For chemotherapy to be effec tive, children also need to comply each year for a number of years. Fa lling rates of compliance over time would reduce the effectiveness of chemotherapy and increase the attractiveness of a vaccine. But on the other hand. even though a vaccine may still be more cost-effective tha n chemotherapy at relatively low levels of vaccine efficacy. if mother s perceived the vaccine to he ineffective and refused to bring their c hildren for vaccination, the success of the entire childhood immunizat ion programme could be threatened.