title: Validation of the combined toxin-binding inhibition test for determination of neutralizing antibodies against tetanus and diphtheria toxins in a vaccine field study in Viet Nam.
abstract: Determination of seroconversion and measurement of protective antibody levels in children against vaccine components are essential for gauging and monitoring the efficacy of paediatric vaccination programmes. For this purpose, we assessed the combined toxin-binding inhibition (ToBI) test for determining neutralizing antibodies to tetanus and diphtheria in a diphtheria-pertussis-tetanus (DPT) vaccine field trial in Viet Nam. A simple procedure involving collection of blood samples on filter-paper was found to be a suitable alternative to collection by venepuncture, despite a reduction in the sensitivity of the ToBI test as a result of the step necessary to elute the antibodies from the filter-paper. The results obtained demonstrate that the ToBI test can feasibly be carried out under field conditions. Preliminary results obtained with the ToBI test in DPT field trials indicate that a fourth dose of DPT vaccine one year after the third dose should be considered by developing countries.
authors.affiliation: Quality Control Department, National Institute of Vaccines and Biological Substances (IVAC), Nha Trang, Viet Nam.
authors.forename: H A
authors.initials: HA
authors.lastname: Hong
authors.forename: N T
authors.initials: NT
authors.lastname: Ke
authors.forename: T N
authors.initials: TN
authors.lastname: Nhon
authors.forename: N D
authors.initials: ND
authors.lastname: Thinh
authors.forename: J W
authors.initials: JW
authors.lastname: van der Gun
authors.forename: J T
authors.initials: JT
authors.lastname: Hendriks
authors.forename: J G
authors.initials: JG
authors.lastname: Kreeftenberg
mesh_terms: D000907:Antibodies, Bacterial / Q000302:isolation & purification*; D004167:Diphtheria Toxin / Q000276:immunology*; D004168:Diphtheria Toxoid; D006801:Humans; D007158:Immunologic Techniques; D007223:Infant; D010865:Pilot Projects; D016036:Seroepidemiologic Studies; D013742:Tetanus / Q000276:immunology*; D013744:Tetanus Toxin / Q000276:immunology*; D013745:Tetanus Toxoid; D014744:Vietnam
chemical_list: D000907:Antibodies, Bacterial; D004167:Diphtheria Toxin; D004168:Diphtheria Toxoid; D013744:Tetanus Toxin; D013745:Tetanus Toxoid