Type-specific action of vibriocidal antibody on Vibrio cholerae.

The vibriocidal activity of Inaba and Ogawa antisera, from which cross-reacting agglutinin had been absorbed, was specific for Vibrio cholerae strains of the homologous serotype. No vibriocidal action against strains of the heterologous type was detected. The sera appeared to be equally effective in killing organisms of different biotypes (classical, intermediate, and EITor), provided that these were of the homologous serotype (Inaba or Ogawa). However, they had been raised against strains of the classical biotype only; and sera resulting from immunization with other biotypes had not been prepared. The implications of these findings in immunity to cholera are discussed.