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 Instituto Butantan (Butang®) were evaluated in 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 percent) 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 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, adolescents, and adults) or 0, 1, and 7 months (children). Vaccine dose was intramuscular 10 æg (infants, children, and adolescents) or 20 æg (adults). Percent seroprotection (assumed when anti-HBs titers were > 10mIU/ml) and geometric mean titer (mIU/ml) were: newborn infants, 93.7 percent and 351.1 (Butang®) and 97.5 percent and 1530.6 (Engerix B®); children, 100 percent and 3600.0 (Butang®) and 97.7 percent and 2753.1 (Engerix B®); adolescents, 95.1 percent and 746.3 (Butang®) and 96 percent and 1284.3 (Engerix B®); adults 20-30 years old, 91.8 percent and 453.5 (Butang®) and 95.5 percent and 1369.0 (Engerix B®); and adults 31-40 years old, 79.8 percent and 122.7 (Butang®) and 92.4 percent 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 newborn infants, adolescents, and young adults.