Norton Healthcare and University of Louisville researchers are studying what drives satisfaction and persistence on long-acting injectable PrEP for HIV prevention. Learn more.

Published: September 23, 2026

Norton Infectious Diseases Institute and the University of Louisville’s Kent School of Social Work & Family Science and School of Public Health & Information Sciences have launched a new joint research effort. The IMPACT study examines what drives medication satisfaction and persistence among patients using long-acting injectable preexposure prophylaxis (LAI-PrEP) for HIV prevention.

The study is enrolling patients who are currently using, or soon starting, injectable PrEP. Its goal is to better understand the factors that help or hinder patients’ ability to stay on this HIV prevention therapy over time.

Why this study matters

PrEP remains the only medication approach available to help prevent HIV. Daily oral PrEP has been available for years, but LAI-PrEP, administered bimonthly (every two months) or biannually (every six months), is a newer option reshaping how clinicians and patients approach prevention.

Persistence on any PrEP regimen depends on more than clinical efficacy. Access to care, side effects and patient satisfaction with the medication all influence whether patients continue treatment. This study is designed to isolate these variables specifically within the LAI-PrEP population, with particular attention to injection-site reactions, satisfaction and comparative persistence between the two dosing intervals.

What makes this study distinct

This study is among the first to examine innovations in LAI-PrEP delivery and the associated benefits and drawbacks for patients. A few features set it apart:

• Multidisciplinary design. The research team spans clinical and social science disciplines, combining perspectives that a single-discipline study could not offer.
• Community-engagement component. Built-in community input helps ensure the study stays responsive to real patient needs rather than research priorities alone.
• Comparative dosing analysis. The study will directly compare bimonthly and biannual LAI-PrEP regimens for both prevention efficacy and long-term patient retention.

Eligibility

• Age 18 or older
• Currently on injectable PrEP, or starting injectable PrEP within 30 days
• Not living with HIV

A Kentucky-based partnership

The study is a collaboration between Norton Infectious Diseases Institute and the University of Louisville — two of the state’s leading HIV research institutions. The team includes researchers, clinicians, social workers and public health professionals from both organizations, working toward a shared goal: helping the broader medical and scientific community optimize novel biomedical approaches to HIV prevention.

Why is this team positioned to lead

Norton Infectious Diseases Institute already provides PrEP services across the community, including injectable formulations, with more than 100 patients currently receiving LAI-PrEP at Norton Healthcare-based clinics. Combined with a prior track record of PrEP-focused collaboration between Norton Healthcare and UofL researchers, the team brings direct visibility into the existing gaps in LAI-PrEP knowledge.

Reviewed by:

Anupama Raghuram, M.D.
Chief Scientific Officer
Norton Infectious Diseases Institute

Lesley Harris, Ph.D., MSW
Professor, University of Louisville Kent School of Social Work & Family Science

Jelani Kerr, Ph.D., MSPH
Associate Professor
University of Louisville School of Public Health & Information Sciences