Protection of suckling mice from experimental cholera by maternal immunization: comparison of the efficacy of whole cell, ribosomal derived, and enterotoxin immunogens

The susceptibility of suckling mice to oral infection with V. cholerae was determined. Mice up to 10 days of age were uniformly susceptible to oral infection with 10⁸ colony forming units of virulent organisms. Age dependent resistance occurred thereafter to a maximum at about 15 days of age. The efficacy of selected vaccines was compared by oral challenge of 8 day old, passively immunized CFW mice. An Ogawa derived ribosomal antigen was found to be superior to a commercial whole cell vaccine or to purified cholera enterotoxin. The ribosomal antigen was 50 to 100 fold more protective than the other vaccines on a weight basis against otherwise lethal challenge with Ogawa, Inaba, or El Tor Ogawa serotypes.