[A new vaccinating antigenic fraction obtained from "Vibrio cholerae" II. Biological properties of the Ch1+2 fraction compared with the bacterial vaccine (author's transl)].

This fraction inoculated into mice protects against experimental infection. This fraction induces in various experimental animals serological modifications which are characterized by a rise in the vibriocidal effect of the serum. Controlled experiments in animals and humans showed that the vibriocidal effect is greater than the one obtained by the bacterial vaccine and persist far more longer. The vibriocidal power of the serum can also be obtained at titers relatively high when the fraction is given by the oral route. The in situ vaccination reduces the duration and the numbers of the excreted bacteries in germ free and pathogen free mice.