The hepatitis B virus (HBV) is the world’s leading cause of liver cancer and the tenth leading cause of death. People who inject drugs (PWID) are at substantial risk for the transmission of hepatitis viruses, through both unsafe injecting and sexual activity.
In Australia, 90 percent of new hepatitis C virus (HCV) infections and 40 percent of new HBV infections occur among PWID. The risk of developing liver disease is greater for individuals co-infected with HCV and HBV, conferring a high cost to the community in terms of future health care.
Despite the availability of an effective HBV vaccine, research has demonstrated that a considerable proportion of PWID in Australia remain unvaccinated.
Through serological testing we have established that one third of participants in current Burnet Institute cohort studies of PWID are not vaccinated and susceptible to HBV infection. For various complex social reasons, many of these participants are not linked in with existing targeted primary health or mainstream health services.
Alternative and innovative means of delivering health services such as HBV vaccination are required to reach this marginalized group to reduce future disease burden and associated healthcare costs.
The aims of this project are to:
- Increase HBV vaccination coverage among participants of current Burnet Institute cohort studies of PWID
- Investigate the feasibility and acceptability of providing HBV vaccination to PWID using an outreach model
- Evaluate the effectiveness of the outreach model for HBV vaccination delivery, completion and HBV surface antibody seroconversion
- Measure the efficacy of the standard vs. opportunistic accelerated schedule in terms of serological immune response and vaccination completion rates.
The B-VAX study is a Randomised Control Trial (RCT), assessing vaccine course completion and immune response between two differing schedules of HBV vaccine administration:
- the standard schedule currently utilised by the Australian National Immunisation Program, which consists of three doses given at 0, 1 and 6 months;
- and an opportunistic accelerated schedule whereby the vaccine will be administered opportunistically in the field at a minimum of 0, 7 and 21 days, with a booster dose given 12 months following the third vaccine if the participant is yet to mount an adequate immune response.
A registered nurse trained in vaccine administration will deliver the vaccine to eligible research participants ‘in the field’ using assertive outreach methods and motivational incentives to maximse vaccination course completion.
Eligible PWID will be identified from existing cohort studies conducted by the Burnet Institute and approached to participate in the immunisation trial either in person in the field or via a letter or text message.
Participants will be eligible if they have been serologically confirmed as susceptible to HBV infection through these studies.
Consenting participants will meet with the nurse in the field, receive a ‘baseline’ vaccination, complete a brief questionnaire and then be randomised into one of the two arms of the study.
The full vaccine course will be administered according the specifications of each arm of the trial, with participants also receiving a blood test after each vaccination and six weeks after the final vaccine in both schedules to determine their serological response to the vaccine.
Participants will be assertively followed-up by the project nurse to encourage vaccine course completion.
They will be paid a small motivational incentive after each contact and we aim to recruit 150 participants.
At the first contact, demographic and behavioral risk data will be collected, and participants surveyed about their knowledge of HBV, including transmission, prevention, and vaccination.
These data together with the baseline data from current cohort studies will later enable us to compare the characteristics of people who completed the vaccination course with those who did not, enabling an assessment of how best to shape and target future immunisation projects.
A subset of the sample (n=30) will be interviewed in depth to further explore the barriers and enablers to seeking and completing vaccination and acceptability of the outreach model of vaccine delivery.
Our experience with providing blood-borne virus counselling and testing ‘in the field’ to this population demonstrates that they respond well to outreach methods. Since starting testing for BBVs in MIX we have achieved a high rate of return for hepatitis C test results by using assertive outreach.
If this trial is successful, then further funding will be sought to conduct the study on a larger scale and investigate options for sustaining such a model.
Our experience with providing blood-borne virus counselling and testing ‘in the field’ to this population demonstrates that this group, who are in need of tailored health interventions, respond well to outreach methods.
For example, we have achieved a high rate of return for hepatitis C test results using assertive outreach.