Facilitating the WHO Expanded Program of Immunization: the Clinical Profile of a Combined Diphtheria, Tetanus, Pertussis, Hepatitis B and Haemophilus Influenzae Type B Vaccine

Background: Vaccines are important weapons in the fight against infectious diseases. The World Health Organization (WHO) Expanded Program on Immunization (EPI) has been extended to include recommendations for hepatitis B and Haemophilus influenzae type b (Hib) vaccinations. The WHO has recommended that combined vaccines be used where possible, to reduce the logistic costs of vaccine delivery. This paper reviews the efficacy, safety and cost-effectiveness of Tritanrix-HB/Hib, the only commercially available combined diphtheria, tetanus, whole cell pertussis, hepatitis B and conjugated Hib vaccine.

Methods: The immunogenicity and reactogenicity results of five published clinical trials involving Tritanrix-HB/Hib in a variety of immunization schedules and countries were reviewed. Based on these data and cost-effectiveness studies, an assessment of its suitability for use in national immunization programs was made.

Results: Tritanrix-HB/Hib has shown excellent immunogenicity in clinical trials using a variety of schedules, with no reduced immunogenicity observed for any of the components of the combined vaccine. It has similar reactogenicity to DTPw vaccines alone. Pharmacoeconomic analyses have shown combined DTP-HB/Hib vaccines to be cost-effective compared to separate vaccines.

Conclusions: Replacement of DTPw vaccination by Tritanrix-HB/Hib can be done without modifying the existing national immunization programs. This should facilitate widespread coverage of hepatitis B and Hib vaccinations and their rapid incorporation into the EPI.