A new combined DTP-HBV-Hib vaccine--strategy for incorporation of Hib vaccination into childhood immunisation programmes

Abstract

Objectives: To evaluate the immunogenicity and reactogenicity of a pentavalent vaccine prepared by extemporaneously mixing diphtheria-tetanus pertussis-hepatitis B vaccine (DTP-HBV) and lyophilised Haemophilus influenzae type B (Hib)-tetanus conjugate vaccines in the same syringe, compared with the same vaccines given as separate, concomitant administrations.

Design: Open, randomised comparative study.

Setting: Durban, South Africa.

Subjects: A total of 120 healthy male and female infants were enrolled in the trial and randomised into two groups; group 1 received the combined administration (DTP-HBV-Hib), and group 2 received separate administrations of DTP-HBV and Hib vaccines. Vaccines were given as a three-dose primary vaccination course at 2, 4 and 6 months [corrected] of age.

Outcome measures: Antibody levels were measured using standard techniques and local and general solicited symptoms were recorded using diary cards.

Results: All subjects had seroprotective titres against diphtheria and tetanus; and antipolyribose-ribitol phosphate (PRP) titres > or = 0.15 microgram/ml 1 month after the final dose. A vaccine response (defined as post-vaccination titres > or = 15 ELISA (EL).U/ml in initially seronegative subjects; and as post-vaccination titres > or = pre-vaccination titres in initially seropositive subjects) against the pertussis component was seen in 83% and 85% of subjects in the groups receiving combined and separate administration. No differences were seen in any of the geometric mean titres (GMTs) between the two administrations either 2 months after the second dose or 1 month after the final dose. There was no observed increase in reactogenicity in the group receiving the mixed administration.

Conclusions: The results demonstrate that combined DTP-HBV-Hib vaccine is well tolerated and immunogenic.