Hepatitis B component does not interfere with the immune response to diphtheria, tetanus and whole-cell Bordetella pertussis components of a quadrivalent (DTPw-HB) vaccine: a controlled trial in healthy infants.

The aim of this single-blind, parallel trial was to assess whether the hepatitis B (HB) component of a DTPw-HB vaccine interferes with the immune response to the other three components when administered at 3, 5 and 7 months of age. One hundred and six infants were randomized to receive three doses of DTPw or DTPw-HB vaccines. Seroprotection (or seroresponse) rates and geometric mean titers (GMT) of antibodies were assessed 3-6 weeks after the third dose. Anti-diphtheria, anti-tetanus and anti-Bordetella pertussis antibodies were measured by ELISA and anti-HBs by radioimmunoassay. Local and general signs and symptoms were recorded for a 4-day follow-up period after each vaccination. After the full vaccination course all subjects in both groups had seroprotective titers (> or = 0.1 IU ml-1) against diphtheria and tetanus and seroresponded (titers > or = 15 EL.U ml-1) to B. pertussis, and there was no significant difference between groups in relation to GMT. All subjects vaccinated with DTPw-HB had seroprotective levels (> or = 10 mIU ml-1) of anti-HBs antibodies after the third dose (GMT of 2318 mIU ml-1). Overall there were no significant differences between groups in relation to the incidence of local and general symptoms. These results show that the HB component did not interfere with the immune response to the other three components of the vaccine.