Immune memory responses to HBV vaccine 13-18 years after primary vaccination.

The aim of this study was to evaluate the immune memory response 13-18 years after an hepatitis B virus (HBV) vaccine by performing a specific in vitro stimulation experiment. Thirty healthy volunteers who had been inoculated 13-18 years ago with the HBV vaccine were collected from the physical examination center. Peripheral blood mononuclear cells were stimulated with 50 ng/mL recombinant HBsAg. An ELISA kit was used for the detection of antibodies that were produced by these cells in vitro. It was found that even 13-18 years after inoculation with the HBV vaccine, an anamnestic antibody response still existed, and was not correlated with the serum antibody levels (r = -0.177, P = 0.377). In conclusion, our data showed that the individuals after inoculation, including those with anti-HBs <10 IU/L as well as those individuals in whom the antibody was not detected, retained immune memory, which may be the main role of memory B cells.