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 com parable to and can replace Plasma-Derived Hepatitis B Vaccine (PHB vac cine) for the prevention of mother-infant transmission of hepatitis B virus (HBV), but the duration of immune efficacy of RYHB vaccine is no t clear. This study indicates the long-term efficacy for the preventio n of mother-infant transmission of HBV. One hundred and six neonates b orn to HBsAg-carrier mothers with HBeAg positive were randomly divided into two groups, one receiving 20 mu g per dose of RyHB vaccine and t he another receiving 20 mu g per dose of PHB vaccine on the day of bir th, 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 6 0 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% an d 18%, respectively for the PHB vaccine group. The protective efficacy was notably significant in the last two years. The study indicates th at the duration of protective efficacy is over 5 years with RYHB vacci ne, being longer than that of RYHB vaccine showed no side effects, and the vaccine is regarded as safe and effective.