Willingness to participate in hepatitis C vaccine trials among socially marginalized people who use drugs.

A major complicating factor for hepatitis C virus (HCV) vaccine clinical trial design and implementation is engagement and retention of people who use drugs (PWUD). Informed willingness to participate (WTP) in vaccine trials has emerged as a critical issue to describe, understand, and promote among populations at increased risk of communicable disease incidence. The present study addressed this topic by examining correlates of WTP among 320 socially marginalized PWUD as part of the Edmonton Drug Use and Health Survey (EDUHS). WTP was analyzed in relation to: gender, age, housing stability, ethnicity; self-reported hospital care in the past six months, self-reported injection drug use in the past 6 months, lifetime addiction treatment for alcohol or drugs, severity of drug use problems, and unmet healthcare needs. EDUHS participants reported high rates of current injection drug use (91%), and about two-thirds (67.3%) reported a lifetime HCV positive status. HCV positive respondents were older, had more severe substance use problems, and reported injecting drugs more frequently, compared to HCV negative respondents. Among the subsample of HCV negative respondents, 81% affirmed that they would be willing to enroll in a HCV vaccine prevention trial. Those reporting WTP were more likely to have had a recent hospital admission, to report more total unmet healthcare needs, and greater unmet needs for information, hospital care, and counseling, compared to HCV negative respondents not willing to enroll in a vaccine trial. No association was observed between WTP and other assessed variables. Results suggest that connecting PWUD not infected with HCV to local healthcare resources may be important in motivating vaccine trial participation.