This study for the first time characterizes OSP-specific serum, mucosal and memory B cell responses in adults vaccinated with two doses of an oral cholera vaccine, Shanchol, in Bangladesh where it has been shown that OSP-specific serum and mucosal immune responses, as well as IgA memory B cell responses are maximal following the first dose of vaccination, without evident boosting with the second dose. This evidence concerns the gene CD79A and vibrio infectious disease.