LONG-TERM IMMUNOGENICITY AND EFFICACY OF RECOMBINANT YEAST-DERIVED HEPATITIS-B VACCINE FOR INTERRUPTION OF MOTHER-INFANT TRANSMISSION OF HEPATITIS-B VIRUS

Recombinant DNA Yeast-Derived Hepatitis B Vaccine RYHB vaccine) is comparable to and can replace Plasma-Derived Hepatitis B Vaccine (PHB vaccine) for the prevention of mother-infant transmission of hepatitis B virus (HBV), but the duration of immune efficacy of RYHB vaccine is not clear. This study indicates the long-term efficacy for the prevention of mother-infant transmission of HBV. One hundred and six neonates born to HBsAg-carrier mothers with HBeAg positive were randomly divided into two groups, one receiving 20 mu g per dose of RyHB vaccine and the another receiving 20 mu g per dose of PHB vaccine on the day of birth, at 1 month and at 6 months (three times). Physical examination adn blood tests were performed for all infants at 6, 12, 24, 36, 48 and 60 months of age. The results showed that the protective efficacies at 6, 12, 24, 36, 48 and 60 months were 67%, 75%, 63%, 62%, 57% and 56%, respectively for the RYHB vaccine group and 58%, 76%, 51%, 41%, 24% and 18%, respectively for the PHB vaccine group. The protective efficacy was notably significant in the last two years. The study indicates that the duration of protective efficacy is over 5 years with RYHB vaccine, being longer than that of RYHB vaccine showed no side effects, and the vaccine is regarded as safe and effective.