Immunogenicity of Recombinant Hepatitis B Vaccine Among Infants of Mothers with Active Schistosomiasis

A study of the immunogenicity of a recombinant hepatitis B vaccine was conducted among 385 Egyptian infants, 191 (49.6%) of whom were born to mothers with moderately active Schistosoma mansoni infection (mean egg count = 224 eggs/g of feces). All mothers were seronegative for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen. Infants were vaccinated with a 2.5-microg dose of this vaccine, given along with diphtheria, tetanus, and pertussis (DTP) vaccine, at the ages of two, four, and six months. Serum samples taken from each infant at nine months of age were tested for HBsAg, antibody to hepatitis B core antigen, and quantitatively for antibody to hepatitis B surface antigen (anti-HBs). There was no significant difference (P = 0.1) between anti-HBs titers in infants of S. mansoni-infected mothers (mean = 539 mIU/ml) and in infants of noninfected mothers (mean = 377 mIU/ml). This study shows that there was no apparent effect of maternal schistosomiasis infection on the immune response of these infants to vaccination.