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 mu g and 20 mu g 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 mu g (IM20 group) or 60 mu g (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 mu g and 60 mu g hepatitis B vaccines showed similar rapid hepatitis B surface antibody decreases.