The B-VAX Project: Providing hepatitis B vaccinations through assertive outreach to people who inject drugs.

INTERVENTION: Intramuscular (IM) provision of the Engerix‐B hepatitis B virus (HBV) vaccine (20 micro g. hepatitis B surface antigen recombinant, pre‐ filled 1.0ml syringe) to eligible participants adhering to a standard schedule of 0, 1 & 6 months. The same vaccine dose will be administered at each timepoint. Participants will be reimbursed $15 and also have serology taken at each vaccine encounter to test for an immune response to the vaccine. Participants will participate in a quantitative questionnaire at baseline. A small sub‐set of the sample will be purposefully selected to participate in a qualitative questionnaire at baseline and third vaccine encounter and will be reimbursed an additional $15 for this. CONDITION: The Hepatitis B Virus (HBV). PRIMARY OUTCOME: Increase HBV vaccination coverage among participants of current Burnet Institute cohort studies of people who inject drugs (PWID) by delivering the HBV vaccine to HBV susceptible participants. This outcome will be assessed upon completion of the B‐VAX project by reviewing the proportion of participants successfully vaccinated within the cohort. SECONDARY OUTCOME: Evaluate the effectiveness of the outreach model for HBV vaccination delivery, completion and HBV Surface antibody seroconversion through analysis of the qualitative data, vaccine course completion rates and seroconversion amongst fully vaccinated study participants. This data will be compared to the outcomes of similar studies. Investigate the feasibility and acceptability of providing HBV vaccination to PWID using an outreach model through analysis of the qualitative data. Measure the efficacy of the standard vs. opportunistic accelerated schedule in terms of serological immune response and vaccination completion rates. INCLUSION CRITERIA: Current Burnet Institute cohort study participants who are serologically confirmed as being susceptible to contracting HBV.