Cost-effectiveness of oral cholera vaccine in a stable refugee population at risk for epidemic cholera and in a population with endemic cholera.

Abstract:  The recent development of safe, reasonably effective oral cholera vaccines has made it possible to consider their use in situations where the risk of epidemic cholera is high. This article reviews the potential cost-effectiveness of the B-subunit killed whole-cell (BS-WC) oral cholera vaccine in both a stable refugee population and a population with endemic cholera. Baseline epidemiologic assumptions were applied to the standard populations to generate the expected morbidity and mortality levels for cholera and simple diarrhea; then, the net costs per case and per death averted by various interventions were calculated. In the population at risk for endemic cholera, the net costs per disability-adjusted life year (DALY) averted are considerably higher since incidence and access to health care are lower. In this population, mass vaccination with BS-WC vaccine is the least cost-effective intervention compared with the provision of safe drinking water and sanitation or with treatment of the disease. In the refugee population, the net costs per DALY averted are much lower since attack rates are higher and access to health care facilities is assumed to be 100%. In this population, the cost-effectiveness for vaccination is similar to that of providing safe drinking water and sanitation alone and less cost-effective than treatment alone or treatment combined with the provision of water and sanitation. Ultimately, the relative cost-effectiveness of an oral cholera vaccine will depend not only on its safety, effectiveness, and duration of protection against the El Tor biotype, but also on the feasibility of administering it to high-risk populations.