This randomized controlled trial will test the efficacy of "PrEP for Health," a behavioral intervention to improve the use of antiretroviral pre-exposure prophylaxis (PrEP) among at-risk people who inject drugs (PWID) in two syringe service program (SSP) settings in Lawrence and Boston/Cambridge, Massachusetts. The investigators will equally randomize 200 PWID to receive either (a) the "PrEP for Health" intervention condition involving theory-informed HIV and PrEP education, motivational interviewing, problem-solving and planning, and ongoing patient navigation (n=100), or (b) the standard of care condition involving PrEP information and referrals (n=100). Successful PrEP uptake (via medical/pharmacy records), post-treatment PrEP adherence (assessed at 3 months via drug levels in hair), and longer-term PrEP adherence (assessed at 6 and 12 months via drug levels in hair) will be evaluated. The degree to which intervention efficacy occurs through specific conceptual mediators and differs according to hypothesized moderators will also be evaluated.

The overall goal of this proposal is to evaluate the efficacy of the "PrEP for Health" navigator delivered behavioral intervention in improving PrEP uptake (via medical/pharmacy records), post-treatment PrEP adherence (assessed at 3 months via drug levels in hair), and longer-term PrEP adherence (assessed at 6 and 12 months via drug levels in hair) among PWID in SSPs. Eligible PWID (n=200 total; 100 recruited from each study site) will be equally randomized to an active PrEP for Health intervention arm (n=100) or a Standard of Care control condition (n=100). Assessments will be conducted at baseline and 1, 3, 6, and 12 months after randomization.

We hypothesize that brief, multi-component behavioral intervention sessions with ongoing support delivered by trained PrEP Navigators within Syringe Service Programs (SSPs) will improve PrEP uptake, adherence, and long-term adherence in PWID by increasing HIV and PrEP knowledge (including alleviating concerns about side effects), increasing HIV risk perceptions and PrEP interest and motivation, improving PrEP use self-efficacy and behavioral skills, and reducing structural barriers over time. Based on our formative research, we also hypothesize that the strength of intervention effects may differ by key individual characteristics (age, gender, baseline sexual risk, polysubstance, and stimulant use).

This is a randomized control trial (RCT). Participants will be recruited via outreach specialist at SSP sites and during routine community outreach practices of the organizations. After eligibility confirmation and baseline assessments, participants will be randomized to one of two study arms: 1) Standard of Care (SOC) Control Condition: as routinely provided through the SSP study sites, participants will receive information and services according to routine practice and a brief video that describes what PrEP is and how it works to prevent HIV via sexual and injection transmission; 2) "PrEP for Health" Intervention Condition: a trained PrEP Navigator will deliver a manualized PrEP uptake and adherence intervention in private counseling rooms at SSPs followed by 3 months of additional PrEP navigation support through in-person, phone, and text interactions as needed. Participants will complete a total of four follow-up visits over a 12-month period. Participants who initiate PrEP will have a hair sample collected at 3-, 6-, and 12-month visits. All participants will receive a rapid HIV screening test at 12-month follow-up.

Inclusion Criteria:

• HIV-uninfected (verified by rapid/4th generation test)
• Reporting past-month injection of any drugs
• One or more HIV risk behaviors (past-month receptive syringe sharing, transactional sex, or condomless sex with an HIV-infected or unknown-status partner)
• Not currently on and never taken PrEP
• Able to understand and speak English or Spanish

Exclusion Criteria:

• Unable to provide informed consent due to severe mental or physical illness, cognitive impairment, or substance intoxication at the time of enrollment
• Living in Massachusetts (MA) for <3 months
• Planning to move out of MA within a year

By request to the study investigators

Data will be available after the study has closed and after publication of the primary study findings.

Requests will be reviewed by the principal investigators.

Individuals collecting the primary outcome data will be blinded to intervention condition.