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

ABSTRACT

The immunogenicity and safety of a new recombinant hepatitis B vaccine from the Istituto Butantan (Butang) were evaluated ina a multicenter, double-blind prospective equivalence study in three centers in Brazil. Engerix B was the standard vaccine. A total of 3937 subjects were recruited and 2754 (70 per cent) met a 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 infants (566), children 1 to 10 years old (484), adolescents from 11 to 19 years (740), adults from 20 to 30 years (568), and adults from 31 to 40 years(396). Vaccine was administered in three doses on the schedule 0, 1, and 6 months (newborn infants, children, and adolescents) or 20 ug (adults). Percent seroprotection (assumed when anti- HBs titers were >- 10mIU/ml) and geometric mean titer (mIU/ml) were newborn infants, 93.7 per cent) and 351.1 (Butang and 97,5 perc cent and 1530.6 (Engerix B); children, 100 per cent and 3600.0 (Butang R and 97.7 per cent and 2753.1 (Engerix B); adolescents, 95.1 per cent and 746.3 (Butang and 96 per cent and 1284.3 (Engerix B); adults 20-30 years old, 91,8 per cent and 453.5 (Butang) and 95.5 per cent and 1369.0 (Engerix B); and adults 31-40 years old, 79,8 per cent and 122.7 (Butang) and 92.4 per cent and 686.2 (Engerix B). There were no severe adverse events following either vaccine. The study concluded that Butang was equivalent to Engerix B in children and less immunogenic but acceptable for use in mewborn infants, adolescents, and young adults...(AU)