Immunogenicity of Haemophilus influenzae b conjugate vaccine (HibTITER) and safety of HibTITER and a combination vaccine of diphtheria, tetanus, pertussis and HibTITER in infants two months of age: a preliminary report.

A study was undertaken to evaluate the safety and immunongenicity of a conjugate Haemophilus influenzae type b (Hib) vaccine (HibTITER) when administered concurrently with DTP (diphteria, tetanus and pertussis) vaccine in separate syringes. A total of 90 healthy children (45 per group) were randomized to receive either TETRAMUNE, a vaccine combining HibTITER with whole-cell DTP (group A), or DTP and HibTITER administered concurrently (group B) in separate syringes at approximately 2, 4 and 6 months of age in Taiwan. All children in group B achieved anti-Hib PRP (polyribosylribitol phosphate) antibody titers above 0.15 microgram/ml and 91% developed antibody titers above 1.0 microgram/ml following the third immunization. Incidences of adverse reactions were comparable between groups A and B. Besides, the incidences of adverse reactions were not significantly more frequent compared with DTP vaccination alone. We concluded that HibTITER was highly immunogenic and safe when administered concurrently with DTP vaccine to Taiwanese children. TETRAMUNE was also safe and the number of injections may be reduced in the future.