IMMUNOGENICITY OF HEPATITIS-B VACCINES AMONG INFANT RECIPIENTS OF ACELLULAR AND WHOLE-CELL PERTUSSIS DTP VACCINES

The study was conducted to assess the immunogenicity of three doses of two recombinant hepatitis B virus (HBV) vaccines, administered simult aneously with a DT vaccine or one of three different pertussis vaccine s combined with diphtheria and tetanus toxoids. The study population c onsisted of 1237 children selected from the cohort of 15 601 children enrolled in the Italian trial on pertussis vaccines. HBV vaccination w as performed at 2, 4 and 12 months of age, with the first two doses co ncurrent with OPV and DTP vaccination. The DTP vaccines administered i n the pertussis trial included one whole cell DTP, licensed in the USA , and two three-component acellular DTaPs, manufactured in Europe. Imm unogenicity to HBV was evaluated on serum samples collected 9 months a fter dose of HBV vaccine. Antibodies against HBsAg were detected by EL ISA and expressed in mlU/ml. In 13 children, the antibody response was below the protective level of 10 mlU/ml(-1). No statistical differenc e was found among the various study groups with respect to the proport ion of children showing protective response. Higher humoral response w as observed in children receiving mixed HBV vaccines in each pertussis study groups. (C) 1998 Elsevier Science Ltd. All rights reserved.