Long-term durability of immunogenicity induced by standard and triple-dose hepatitis B vaccine in patients receiving methadone maintenance treatment.

OBJECTIVES

We explored the long-term immunogenicity induced by 60 μg and 20 μg hepatitis B vaccines among patients receiving methadone maintenance treatment (MMT).

METHODS

In initial study, a randomized controlled trial was conducted, in which patients receiving MMT were administered 20 µg (IM20 group) or 60 µg (IM60 group) hepatitis B vaccines at months 0, 1, and 6. In this study, the responders at month 7 were followed-up at months 18, 30, and 42 to estimate long-term immunogenicity.

RESULTS

The response rate decreased from 78.0% (39/50) to 31.1% (14/45) in the IM20 group, and from 86.0% (43/50) to 50.0% (20/40) in the IM60 group from month 7 to 42. Vaccine-induced responses in 75% of patients were observed for 14.2 months in the IM20 group and for 20.0 months in the IM60 group, and differences between these two groups were non-significant (P > 0.05).

CONCLUSION

The three-dose 20 µg and 60 µg hepatitis B vaccines showed similar rapid hepatitis B surface antibody decreases. Abbreviations: HBV, hepatitis B virus; MMT, methadone maintenance treatment; HCC, hepatocellular carcinoma; HBsAg, hepatitis B surface antigen; anti-HBs, hepatitis B surface antibody; HR, hazard ratio; CI, confidence interval; IQR, interquartile range; GEE, generalized estimated equation.