In this study, the investigators will test the mobile game, Viral Combat, for efficacy and acceptability among diverse participants, ages 15-34 years, receiving PrEP care in clinical settings in New England and Mississippi. Formative evaluation interviews will be conducted with stakeholders (healthcare workers, clinic administrators, and patients taking PrEP) to inform intervention delivery. Data from the formative interviews will also be used to make necessary adaptations to the game and assess acceptability for diverse populations and clinics. Viral Combat will then be further tested with 200 participants ages 15-34 years, receiving PrEP care at clinical sites in the South (n=100 Jackson, MS) and New England (n=100, Providence, RI; Boston, MA) in a multisite Hybrid Type 1 effectiveness-implementation randomized controlled trial (RCT). This trial will test the efficacy of the intervention compared to a control condition (a non-PrEP related game) on biological and behavioral measures. At the end of the trial, a summative evaluation of the implementation context using the i-PARIHS framework will occur. These interviews with study participants and clinic staff will inform future implementation and dissemination of Viral Combat.

In this study, the investigators will test the mobile game, Viral Combat, for efficacy and acceptability among diverse participants, ages 15-34 years, receiving PrEP care in clinical settings in New England and Mississippi. Formative evaluation interviews will be conducted with stakeholders (healthcare workers, clinic administrators, and patients taking PrEP) to inform intervention delivery. Data from the formative interviews will also be used to make necessary adaptations to the game and assess acceptability for diverse populations and clinics. Viral Combat will then be further tested with 200 participants ages 15-34 years, receiving PrEP care at clinical sites in the South (n=100 Jackson, MS) and New England (n=100, Providence, RI; Boston, MA) in a multisite Hybrid Type 1 effectiveness-implementation randomized controlled trial (RCT). This trial will test the efficacy of the intervention compared to a control condition (a non-PrEP related game) on biological and behavioral measures. At the end of the trial, a summative evaluation of the implementation context using the i-PARIHS framework will occur. These interviews with study participants and clinic staff will inform future implementation and dissemination of Viral Combat.

Aim 1: To conduct formative evaluation interviews, guided by the i-PARHIS framework, with approximately 30 stakeholders (23 PrEP patients, 4 clinical staff, 3 clinic administrators) in order to adapt Viral Combat for diverse PrEP patient populations, and to identify individual, organizational, and structural factors associated with its implementation.

Aim 2: To evaluate, in a Hybrid Type 1 effectiveness-implementation randomized controlled trial with 200 participants taking PrEP (15-34 years of age), the effectiveness of Viral Combat compared to a control group that receives a non-PrEP related game.

The investigators will examine the impact of the intervention on:

2a: improving adherence to PrEP using a biological measure (tenofovir from DBS), clinic records, and self-report; 2b: the potential mediators of the intervention, such as knowledge, motivation, self-efficacy, and game metrics.

Aim 3: To conduct summative evaluation interviews, following the RCT phase, with an additional 30 stakeholders ((23 PrEP patients, 4 clinical staff, 3 clinic administrators). Interviews will assess and summarize the i-PARIHS constructs relevant to the intervention's future implementation success.

Inclusion Criteria:

• 15-34 years old
• English speaking
• Initiated PrEP in the last 30 days or re-initiated PrEP after not taking PrEP for at least 1 month
• HIV negative as per clinician and clinical record
• Able to give consent/assent and not impaired by cognitive or medical limitations as per clinical assessment.

Exclusion Criteria:

• None