The hows and whys of constructing a native recombinant cholera vaccine.

Emergence of different ctxB genotypes within virulent Vibrio cholerae populations accentuates the need to develop a vaccine that has the potential to protect against all cholera toxin genotypes. Oral administration of rCTB-alone and in combination with 2 dominant domestic killed whole cells of V. cholerae (O1 Ogawa El Tor and O1 Inaba El Tor) plus one standard V. cholerae (O1 Ogawa classic ATCC 14035)-has shown satisfactory protection as a potent vaccine candidate against toxigenic V. cholerae.