A brief peer-led intervention to increase COVID-19 vaccine uptake among people who inject drugs in San Diego County: Results from a pilot randomized controlled trial

Abstract Background We evaluated the impact of a brief, peer-led intervention on COVID-19 vaccination among people who inject drugs (PWID) presenting at syringe services program (SSP) locations in San Diego County, California. Methods Between March and July 2022, PWID aged ≥18 years old without recent voluntary testing were not up to date vaccinations received single-session motivational interviewing (“LinkUP”) or an attention-matched didactic control condition from trained peer counselors SSP sites randomized by week. Following either 30-minute session, offered referrals local services. Multivariable log binomial regression via generalized estimating equations assessed LinkUP effects i) acceptance immediately post-intervention ii) vaccine uptake six-month follow-up. Results Of 149 participants, outcomes obtained 135 (90.6%). In multivariable analysis, participants receiving had greater than controls (Adjusted Relative Risk [AdjRR]: 3.50; 95% CI: 1.01, 12.2) marginally more likely report new dose (AdjRR: 1.57; 0.99, 2.48). After six months, 20% reported dose; however, if been available SSPs, this proportion could have as high 34.3% (45.3% vs. 24.3% control; p=0.01). Conclusions A brief SSP-based significantly improved PWID. Further improvements be supporting SSPs offer onsite instead relying referrals.