Public Health Considerations for the Use of Cholera Vaccines in Cholera Control Programs

Conventional parenteral cholera vaccines have largely been abandoned as public health tools, and recent studies have elucidated the probable reason for their poor performance. This chapter reviews the reasons that older parenteral cholera vaccines have largely been abandoned as public health tools. It also discusses several considerations that should be addressed when judging whether new cholera vaccines are sufficiently attractive to be used in public health programs. The chapter focuses to the use of cholera vaccines in populations residing in areas affected by cholera and do not specifically consider the problem of vaccinating travelers to such areas. In developing countries, cholera may occur in either epidemic or endemic form. A basic requirement for making a rational decision to launch a cholera vaccine program is that the burden of cholera morbidity and mortality be sufficient to warrant the diversion of scarce resources necessary for such a program. Several protective characteristics of a cholera vaccine must be considered when its potential utility in public health programs is evaluated. Heterogeneity of vaccine protection, which depends on characteristics of the host and of the infecting vibrio, must also be contemplated, though again, the importance of such heterogeneity will vary with the epidemiologic setting for vaccination. The formulation of a vaccine may have an important influence on cultural acceptability.