title: Short-term booster effect of diphtheria toxoid in initially long-term protected individuals.
abstract: The main objective of this study was to investigate the booster antibody response in individuals with initially high levels of diphtheria antitoxin. Sixty individuals eligible for the routine booster by the age of 18 years each received a single dose of 5 Lf of diphtheria toxoid in diphtheria-tetanus vaccine. A double antigen ELISA was used for the assessment of the antibody levels. Chaotropic disruption in paired ELISA was used to test antibody avidity. The ratio between initial and maximum antibody concentrations after 1 month was >10 times higher and after 6 months still four times higher in those with initial antibody levels <1 IU/ml. In individuals with initial antibody levels >/=1 IU/ml a two-fold decrease was observed after 6 months compared to the initial levels. Thus, vaccination of individuals with initial long-term protection against diphtheria (antibody levels >/=1 IU/ml) is unnecessary and should be avoided.
authors.affiliation: Institute of Medicine, Centre for International Health, University of Bergen, Norway.
authors.forename: Elena
authors.initials: E
authors.lastname: Danilova
authors.forename: Alexey
authors.initials: A
authors.lastname: Shiryayev
authors.forename: Vegard
authors.initials: V
authors.lastname: Skogen
authors.forename: Einar Klaeboe
authors.initials: EK
authors.lastname: Kristoffersen
authors.forename: Haakon
authors.initials: H
authors.lastname: Sjursen
mesh_terms: D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood; D004165:Diphtheria / Q000276:immunology / Q000517:prevention & control*; D004168:Diphtheria Toxoid / Q000008:administration & dosage* / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007117:Immunization, Secondary; D008297:Male; D012426:Russia
chemical_list: D000907:Antibodies, Bacterial; D004168:Diphtheria Toxoid