title: Safety and immunogenicity of a recombinant hepatitis B vaccine manufactured by a modified process in healthy infants.
abstract: A recent randomized, double-blind study carried out in healthy infants has demonstrated comparable safety and higher immunogenicity of modified process hepatitis B vaccine (mpHBV) - a novel hepatitis B vaccine with enhanced phosphate content in the aluminum adjuvant - compared with Recombivax HB™. Each infant was assigned to receive either 5 µg mpHBV vaccine, 10 µg mpHBV vaccine, 5 µg Recombivax HB vaccine or 10 µg Engerix-B vaccine at 2, 4 and 6 months of age. Findings of this study showed that 1 month after the third vaccine administration, both 5 µg mpHBV and Recombivax HB were able to induce adequate antibody seroprotection rates (SPRs; ≥10 mIU/ml), thus meeting the primary end point. Geometric mean titers (GMTs) were significantly higher among infants who were given either 5 or 10 µg of mpHBV formulations than among those who received Recombivax HB or Engerix-B. In addition, the 5 µg mpHBV over Recombivax HB GMT ratio indicates the noninferiority of the former vaccine compared with the latter. Finally the 10 µg mpHBV/5 µg mpHBV GMT ratio did not show superiority even though the difference was significant. These findings show that the enhanced content of the phosphate component contained in the mpHBV vaccine can potentiate the immune response to hepatitis B surface antigen by making it more available for uptake by dendritic cells. Additional studies are needed to establish whether this novel vaccine may be of benefit in improving immune responses in people who are less responsive to the currently licensed vaccines.
authors.affiliation: Department of Public Health-Microbiology-Virology, University of Milan, Via C Pascal 36, 20133 Milano, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Romanò
authors.forename: Alessandro R
authors.initials: AR
authors.lastname: Zanetti