Background: Severe dehydrating cholera due to V. cholerae O1 is an important public health problem in Bangladesh and many other developing countries. V. cholerae O1 is a major bacterial pathogen causing around 5 million cases and at least 200,000 deaths in adults and children each year. It can be assumed that there are at least 300,000 severe cases and 1.2 million infections in people in Bangladesh alone. The rate of cholera varies from around 1 to 8 per 1000 population and the highest attack rate is in children 2- to 9-year years of age . Cholera is now also being documented in very young children. Currently enteric vaccine approaches are regarded as the most accessible short term and practical means to prevent and control such illnesses to prevent disease and epidemics in resource poor settings with limited public health and sanitary facilities.