Mosley et al. in two excellent epidemiologic studies were able to demonstrate an inverse correlation between vibriocidal titres and incidence of disease [1,2], i. e. the higher the titer the lower incidence of cholera. The population was living in an endemic area and vibriocidal antibody titers appeared to develop during the first 2 years of life and become prevalent by the age of 10 [1]. Vaccine administration in this population doubled the mean vibriocidal titer and was associated with 50–60% reduction in cholera case rate [2]. These results have been suggested to be unique for en endemic area [1]. Repeated exposure by mouth of ‘small’ inocula of cholera vibrios apparently leads to the immunity documented by the above studies. In a non-endemic area such as in the volunteer experimental set up one can hopefully assess the importance of humoral antibodies induced by vaccine or prior disease on the incidence of experimental cholera. If circulating antibodies are significant in providing protection or are only a measure of the extent of prior cholera or cross reacting antigen exposure, studies in a non-endemic population may help to differentiate these suggested roles for humoral antibody. This presentation will cover some serologic data collected from inmate volunteers enrolled in studies designed to evaluate vaccine induced and disease acquired immunity against cholera.KeywordsEndemic AreaHumoral AntibodySerum SpecimenOral VaccineSerologic DataThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.