Immunogenicity and safety of a high-dose hepatitis B vaccine among patients receiving methadone maintenance treatment: A randomized, double-blinded, parallel-controlled trial

•The high dose (60μg) recombinant hepatitis B vaccination showed a numerically better immunogenicity than low dose (20μg) vaccine among the methadone maintenance treatment (MMT) patients.•Vaccinated with hepatitis B vaccination, geometric mean concentration (GMC) of anti-HBs among the MMT patients peaked at month 7, and declined at month 12, and GMC of anti-HBs, seroconversion and high-level response rates among the MMT patients decreased over time.•Both HIV infection and concomitant drug abuse were significant predictive factors for strong response in MMT patients after hepatitis B vaccination.