title: Immunogenicity and reactogenicity of combined versus separately administered DTPw-HBV and Hib vaccines given to healthy infants at 2, 4 and 6 months of age, with a booster at 18 months.
abstract: OBJECTIVE
  To determine the immunogenicity and reactogenicity of a combined DTPw-HBV/Hib vaccine, in comparison with DTPw-HBV and Hib vaccines given as separate concomitant injections.
  
  
  METHODS
  In an open, randomized study, healthy infants were injected with either DTPw-HBV/Hib vaccine or separate DTPw-HBV and Hib vaccines at 2, 4 and 6 months of age, with a booster at 18 months.
  
  
  RESULTS
  Both vaccination regimens were immunogenic, with seropositivity rates of 100% after the booster vaccination for all vaccine components. Even as early as 2 months after the second dose of the primary vaccination, most patients had seroprotective antibody titers, the proportion of seropositive subjects approaching 100% for tetanus, hepatitis B, and Hib. Post-primary and post-booster geometric mean titers (GMTs) were well above seroprotective thresholds for each vaccine antigen in both groups, with no clinically relevant differences in the groups. The separate and combined administrations showed comparable reactogenicity profiles, and neither showed a significant increase in reactogenicity with successive doses.
  
  
  CONCLUSIONS
  The results of this study support the combination of Hib and DTPw-HBV vaccination in routine infant immunization at 2, 4 and 6 months of age with a booster at 18 months. Maximum benefit is obtained from compliance with the full course, but substantial benefit is likely to be achieved even in partially compliant patients, provided they receive at least two doses. Furthermore, these results demonstrate the tolerability of a fourth (booster) administration, where the addition of the Hib vaccine to DTPw-HBV did not lead to an increase in the overall reactogenicity.
authors.affiliation: Universidad Austral de Chile, Valdivia, Chile.
authors.forename: Stella
authors.initials: S
authors.lastname: Riedemann
authors.forename: Germán
authors.initials: G
authors.lastname: Reinhardt
authors.forename: Jaime
authors.initials: J
authors.lastname: Jara
authors.forename: Richard
authors.initials: R
authors.lastname: Rios
authors.forename: María Soledad
authors.initials: MS
authors.lastname: Wenzel
authors.forename: Paul
authors.initials: P
authors.lastname: Willems
authors.forename: Hans L
authors.initials: HL
authors.lastname: Bock
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D005260:Female; D006192:Haemophilus Infections / Q000517:prevention & control; D018073:Haemophilus Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D019741:Haemophilus influenzae type b / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D006801:Humans; D007117:Immunization, Secondary; D007223:Infant; D008297:Male; D017778:Vaccines, Combined / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000914:Antibodies, Viral; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D018073:Haemophilus Vaccines; D017325:Hepatitis B Vaccines; D017778:Vaccines, Combined