Studies on vaccination against bacillary dysentery. 4. Oral immunization with live monotypic and combined vaccines.

Results of tests made in 1964 confirm the previous findings that live oral vaccine, prepared from streptomycin-dependent strains of shigellae, confers a strong, type-specific protection against acute bacillary dysentery. This vaccine did not reduce the carrier rate of shigellae. Observations on soldiers treated with a vaccine of Shigella flexneri serotypes 2a and 3 combined revealed no antagonizing effects from the type 3 component upon the protective effect of the 2a component contained in the same vaccine.