Abstract
To help achieve universal infant immunisation against hepatitis B, the World Health Organisation has recommended the development of a combined diphtheria, tetanus and pertussis (DTP) and hepatitis B vaccine (HBV). The advantages come from the fact that DTP coverage is estimated to be over 80% worldwide and a combined DTP-HB vaccine would increase the coverage of HBV. This study was conducted to compare the immunogenicity and reactogenicity of a combined DTP-HB vaccine with separate, concomitant administration of DTP and HBV vaccines. One hundred and twenty infants were randomised in a 1:1 ratio to one of the two vaccination regimens, given as three injections at approximately 3, 4 and 5 months of age. The only difference in immunogenicity between the two regimens was a higher antibody response to hepatitis B in the group given the combined vaccine, possibly as a result of the adjuvant effect of the whole cell pertussis component of the DTP vaccine. Both vaccine regimens were well tolerated.