title: Oral immunization with Salmonella typhi Ty21a-based clones expressing Vibrio cholerae O-antigen: serum bactericidal antibody responses in man in relation to pre-immunization antibody levels.
abstract: Previous studies have shown that oral immunization with Salmonella typhi Ty21a-based clones expressing Vibrio cholerae O-antigen elicits serum antibody responses against the foreign polysaccharide in human volunteers. These responses are conveniently assayed by complement-dependent bacteriolysis of V. cholerae. In this report the bactericidal responses generated by two such clones are analysed in relation to the pre-immunization titres of various serum antibodies. A significant association was found, in that recipients with higher prevaccine titres of anti-V. cholerae bactericidal antibodies were less likely to register significant bactericidal responses following immunization. These results are discussed in relation to the concept of vaccine exclusion.
authors.affiliation: Department of Microbiology & Immunology, University of Adelaide, South Australia.
authors.forename: S
authors.initials: S
authors.lastname: Attridge
mesh_terms: D000284:Administration, Oral; D000907:Antibodies, Bacterial / Q000097:blood*; D022121:Cholera Vaccines / Q000008:administration & dosage / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D019081:O Antigens; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D012485:Salmonella typhi / Q000276:immunology*; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology; D014734:Vibrio cholerae / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D022121:Cholera Vaccines; D019081:O Antigens; D011135:Polysaccharides, Bacterial; D014614:Vaccines, Synthetic