Abstract
To the technical and administrative difficulties encountered by the propagation of Jennerian vaccination among Indochinese populations since the beginning of French colonization, was opposed the will to impose a western prophylactic method. This led to some aberrations, such as attempts of compulsive mass-vaccination with an ineffective and/or unsafe product. There was also an inherent contradiction between the French medical service's proclaimed wish to apply vaccination to the entire Indochinese population and its suspicious attitude concerning the know-how of local practitioners. But the important small-pox endemicity in Indochina also made this tropical area a great ground for experience because it led to advances in vaccine production methods, e.g., from buffaloes, and even in the 'science of immunization'