LONG-TERM EFFICACY AND IMMUNOLOGICAL MEMORY OF PLASMA-DERIVED HEPATITIS B VACCINE 11 YEARS AFTER INITIAL INOCULATION / 药物分析学报

ABSTRACT

ObjectiveTo assess the efficacy and the immunological memory of plasma-derived hepatitis B vac- cine 11 years after the initial inoculation. Methods A randomized, double-blind and placebo-controlled trial design was used. Results The immunogenicity and protection rate of the vaccine were good 1 1 years after vaccination, how- ever, from 9 to 11 years after vaccination, the perscn year HBV infection rate showed no noticeable difference be- tween the vaccine group and placebo-controls. Furthermore, the immunological memory remained 11 years after in- oculation, but was significantly lower than that observed in the past 10 years. Conclusion Vaccine protection wanes over the years. More information is needed to define the appropriate time for vaccine booster doses.