The long-term persistence of hepatitis B surface antibody (anti-HBs) after hepatitis B vaccination among adults harboring isolated hepatitis B core antibody (anti-HBc) is not yet clarified. The present study aimed to assess the immunogenicity and persistence of antibodies in adults 8 years after vaccination. A total of 309 participants including 94 participants in the isolated anti-HBs group and 215 in the control group were recruited in this study. All subjects received three doses of hepatitis B vaccine (20 μg) at 0, 1, and 12 months, followed by testing for serological responses 1 month after the third vaccination. Subsequently, 154 participants were excluded because their anti-HBs data of 8 y after the first vaccination were missing. The prevalence of isolated anti-HBc was about 11.5%, the positive seroprotection rate was 72%, and the geometric mean titer (GMT) value of anti-HBs titer was 24.55 mIU/mL in the isolated anti-HBc group 8 y after three doses of vaccination. No significant difference was detected in the positive seroprotection rate (P = .434) and the GMT values of anti-HBs titers (P = .674) between the isolated anti-HBc and control groups after 8 y. In conclusion, isolated anti-HBc-positive subjects could achieve satisfactory long-term immune effects after hepatitis B vaccination. The GMT values of anti-HBs titers were lower than those of the control group at 1 month, but no significant difference was detected after 8 years.
Keywords: Hepatitis B virus; isolated anti-HBc; vaccine.