This paper, in the context of various cholera vaccine trials during the present century, examines critical issues of vaccine research, and demonstrates how the movement from laboratory to field, and then to routine practice involves the complex interaction between science, state and the public sphere. Through narratives of scientists and administrators, the authors try to show the social negotiations through which knowledge either moves from laboratory to the field or is inhibited in this movement. Several questions of scientific management, organisational structures and scientific diplomacy are addressed, in addition to questions about notions of medical efficacy and of risk and its perception by the different social actors.