The effect of therapeutic vaccination for the treatment of chronic hepatitis B virus infection.

Although oral nucleos(t)ide analogues can lead to suppression of serum hepatitis B virus (HBV) DNA to undetectable levels efficiently, they usually fail to achieve seroclearance of hepatitis B surface antigen (HBsAg), which indicates eradication of HBV infection. In this study, the efficacy of therapeutic vaccination in patients with chronic HBV infection was evaluated by comparing to the control patients. Patients who had achieved complete virologic response following oral nucleos(t)ide analogue treatment for at least 6 months were included. Vaccinated patients were given three intramuscular injections of hepatitis B vaccine that each contains 20 µg of HBsAg. The efficacy of vaccination was assessed by testing for HBsAg seroclearance. A total of 32 consecutive patients were analyzed, which included 15 vaccinated patients and 17 control patients. At month 6, 1 out of 15 vaccinated patients (6.7%) and 1 out of 17 control patients (5.9%) were determined to clear HBsAg from their sera (P = 1.000). A baseline HBsAg titer of ≤100 IU/mL tended to be predictive of HBsAg seroclearance, but the relationship was not significant (P = 0.097). During the follow-up period, virologic relapse occurred in 29 patients, and 9 patients developed hepatitis flare. The cumulative incidences of virologic relapse and hepatitis flare were similar between the vaccinated and control patients (P = 0.077 and P = 0.667, respectively). In conclusion, therapeutic HBV vaccination in patients who had stopped nucleos(t)ide analogue treatment showed limited efficacy for HBsAg seroclearance. To enhance the efficacy and safety of therapeutic HBV vaccination, rational patient selection and novel therapeutic approaches are needed.