title: Serum antibodies against haemophilus influenzae type b and tetanus at 2.5 years of age: a follow-up of 2 different regimens of infant vaccination.
abstract: In 1990-91 we compared 2 Haemophilus influenzae type b (Hib) conjugate vaccines and 2 different regimens of tetanus vaccination, by vaccinating 142 Swedish infants at ages 3, 5, and 12 months, with either PRP-T (the capsular polysaccharide of Hib conjugated to tetanus toxoid) + D (diphtheria toxoid), or with PRP-OMP (PRP conjugated to an outer membrane complex of meningococcus group B) + DT (diphtheria-tetanus toxoid). In this follow-up, antibodies against Hib and tetanus were analyzed in sera from 133 of the children at the age of 2.5 years. Hib antibodies (> or = 0.06 micrograms/ml) were found in 99% of the children of both groups, but 93% of the PRP-T vaccinees had maintained Hib antibodies > or = 0.15 micrograms/ml, as compared with 80% of the PRP-OMP vaccinees (p < 0.05). In 1992, the batch of PRP-OMP was reported to have questionable immunogenicity. Tetanus toxoid (T) antibodies (> or = 0.01 IU/ml) were found in all sera from both groups. All sera with T antibodies < 0.1 IU/ml showed tetanus toxin neutralizing activity. However, only 75% of children vaccinated with PRP-T had T antibodies > or = 0.1 IU/ml, as compared to 97% of children vaccinated with DT (p < 0.001). In conclusion, Hib and tetanus antibodies were well maintained 18 months after primary vaccination, also in the group vaccinated with the batch of PRP-OMP of somewhat low immunogenicity and in the group of infants receiving their primary tetanus vaccination only by the carrier protein of PRP-T.
authors.affiliation: Department of Infectious Diseases, Göteborg University, Sweden.
authors.forename: R M
authors.initials: RM
authors.lastname: Carlsson
authors.forename: B A
authors.initials: BA
authors.lastname: Claesson
authors.forename: T
authors.initials: T
authors.lastname: Lagergård
authors.forename: H
authors.initials: H
authors.lastname: Käyhty
mesh_terms: D000907:Antibodies, Bacterial / Q000032:analysis*; D002675:Child, Preschool; D003017:Clostridium tetani / Q000276:immunology*; D004168:Diphtheria Toxoid / Q000008:administration & dosage*; D022422:Diphtheria-Tetanus Vaccine; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006192:Haemophilus Infections / Q000517:prevention & control; D018073:Haemophilus Vaccines / Q000008:administration & dosage*; D006193:Haemophilus influenzae / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D008297:Male; D013742:Tetanus / Q000517:prevention & control; D013745:Tetanus Toxoid / Q000008:administration & dosage*; D014611:Vaccination; D017778:Vaccines, Combined / Q000008:administration & dosage; D018074:Vaccines, Conjugate / Q000008:administration & dosage
chemical_list: D000907:Antibodies, Bacterial; D004168:Diphtheria Toxoid; D022422:Diphtheria-Tetanus Vaccine; D018073:Haemophilus Vaccines; C055753:Haemophilus influenza type b polysaccharide vaccine-tetanus toxin conjugate; C052180:Haemophilus influenzae type b-polysaccharide vaccine-diphtheria toxoid conjugate; D007074:Immunoglobulin G; D013745:Tetanus Toxoid; D017778:Vaccines, Combined; D018074:Vaccines, Conjugate