Multicenter study on the immunogenicity and safety of two recombinant vaccines against hepatitis B

The immunogenicity and safety of a new recombinant hepatitis B vaccine from the Instituto Butantall (B=Butang(R)) were evaluated in a multicenter double-blind, prospective equivalence study in three centers in Brazil. Engerix B(R) was the standard vaccine. A total of 393 7 subjects were recruited and 2 7 4 (70 %) met all protocol criteria at the end of the study. All the subjects were considered healthy and denied having received hepatitis B vaccine before the study. Study subjects who adhered to the protocol were newborn in ants (566), children 1 to 10 years old (484). adolescents from 11 to 19 years (740), adults from 20 to 30 years (568). and adultsfi-om 31 to '110 years (396). Vaccine was administered in three doses on the schedule 0, 1, and 6 months (newborn infants, adolescents, and adults) or 0, 1, and 7 months (children). Vaccine dose was intramuscular 10 mug (infants, children, and adolescents) or 20 mug (adults). Percent seroprotection (assumed when anti-HBs titers were greater than or equal to 10mIU/ml) and geometric mean titer (mIU/ml) were: newborn infants, 93.7 % and 351.1 (Butang(R)) and 97.5 % and 1530.6 (Engerix B(R)); children, 100 % and 3600.0 (Butang(R)) and 97.7 % and 2753.1 (Engerix B(R)); adolescents, 95.1 % and 7463 (Butang(R)) and 96 % and 1284.3 (Engerix B(R)); adults 20-30 years old, 91.8 % and 453.5 (Butang(R)) and 95.5 % and 1369.0 (Engerix B(R)); and adults 31-40 years old, 79.8 % and 122.7 (Butang(R)) and 92.4 % and 686.2 (Energix B(R)). There were no severe adverse events following either vaccine. The study concluded that Butang(R) was equivalent to Engerix B(R) in children, and less immunogenic but acceptable for use in newborn infants, adolescents. and young adults.