Immunogenicity of hepatitis B vaccine simultaneously administered with the expanded programme on immunisation (EPI)

To assess the immunogenicity of hepatitis B vaccine simultaneously administered with the Expanded Programme on Immunisation (EPI) vaccines, a total of 300 consecutive infants, ranging in age between 6 weeks and 6 months, were alternatively assigned to the revised EPI and to EPI plus plasma-derived hepatitis B vaccine (Hevac B Pasteur). Four dosages (2 mcg or 0.5 ml each) of hepatitis B vaccine were given intramuscularly. HBsAg, anti-HBc, and anti-HBs were determined at day 0 and at day 210 in both groups by radioimmunoassay methods. The anti-HBs titre levels and geometric mean titres (GMTs) were determined at day 180 and day 210. There were three new hepatitis B virus infections in the control group and none in the study group by day 210. The seroconversion rates in the study group were 66% at day 180 and 84% at day 210, the respective GMTs being 116 and 940. Although the duration of observation is short (7 months) and the difference in the rate of infection between the two groups is not statistically significant (P greater than 0.05), the immunogenicity of the vaccine appears to be good. The simultaneous administration of hepatitis B vaccine and the EPI vaccines is logistically ideal. However, we suggest a further study using a larger dose of the Hevac B Pasteur vaccine to find out if a higher seroconversion rate than the 84% observed in this study could be achieved.