Haemophilus influenzae type b disease: impact and effectiveness of diphtheria-tetanus toxoids-acellular pertussis (-inactivated poliovirus)/H. influenzae type b combination vaccines

Pediatr Infect Dis J. 2001 Aug;20(8):767-74. doi: 10.1097/00006454-200108000-00010.


Background: Since 1996 in Germany primary infant immunization against Haemophilus influenzae has been most commonly given in the form of diphtheria-tetanus toxoids-acellular pertussis/H. influenzae type b (DTaP/Hib) or diphtheria-tetanus toxoids-acellular pertussis (-inactivated poliovirus)/H. influenzae type b (DTaP-IPV/Hib) combination vaccines. These combination vaccines elicit lower anti-Hib antibody concentrations than the equivalent Hib conjugate administered as a separate injection, but the clinical relevance of this phenomenon is unknown.

Methods and findings: To assess the impact of DTaP/Hib combination vaccines on the incidence of invasive Hib disease in Germany, two independent surveillance systems, one hospital- and one laboratory-based, were used during 1998 and 1999 for detection of cases. Vaccination histories of all cases detected were obtained by telephone contact with parents or health care providers. During the 2-year study period invasive H. influenzae disease in the <5-year age group continued to fall, with a mean annual incidence of 1.01/100 000 children. National vaccination coverage rates revealed that only 70% of children given DTaP/Hib or DTaP-IPV/Hib received the recommended three doses in their first year of life, but the overall effectiveness of these vaccines was high at 97.5% (95% confidence interval, 96.3 to 98.4) for those who had received at least one dose. In subjects who received the full 3-dose schedule, effectiveness was 98.8% (95% confidence interval, 98.2 to 99.3).

Conclusion: Although it is well-documented that DTaP/Hib vaccines elicit lower anti-Hib titers than separate vaccines, such combinations are effective in reducing the incidence of invasive H. influenzae type b disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Bacterial / blood
  • Child, Preschool
  • Diphtheria-Tetanus-acellular Pertussis Vaccines / administration & dosage*
  • Diphtheria-Tetanus-acellular Pertussis Vaccines / immunology
  • Germany / epidemiology
  • Haemophilus Infections / epidemiology
  • Haemophilus Infections / prevention & control*
  • Haemophilus Vaccines / administration & dosage*
  • Haemophilus Vaccines / immunology
  • Haemophilus influenzae type b / classification
  • Haemophilus influenzae type b / immunology*
  • Haemophilus influenzae type b / isolation & purification
  • Humans
  • Immunization Schedule
  • Incidence
  • Infant
  • Poliovirus Vaccine, Inactivated / administration & dosage*
  • Poliovirus Vaccine, Inactivated / immunology
  • Sentinel Surveillance
  • Vaccination
  • Vaccines, Combined / administration & dosage
  • Vaccines, Combined / immunology


  • Antibodies, Bacterial
  • Diphtheria-Tetanus-acellular Pertussis Vaccines
  • Haemophilus Vaccines
  • Poliovirus Vaccine, Inactivated
  • Vaccines, Combined