“There is nobody who wouldn’t like to”: understanding the motivations behind women’s participation in a Phase I clinical trial for a subdermal HIV prevention implant in KwaZulu-Natal, South Africa

A novel long-acting HIV oral pre-exposure prophylaxis (PrEP) implant was first tested in a Phase I clinical trial in South Africa, and this study sought to understand motivations behind trial participants enrolment, highlighting considerations for recruitment in future studies. Qualitative research was conducted using in-depth interviews (IDIs) with 29 study participants, 18 of whom also participated in focus group discussions (FGDs). Participants were all Black, African women with median (IQR) age 26 (21.5-29.5) years. Of the 29 participants interviewed, 27 (93%) mentioned intrinsic motivations for enrolling on the trial, including wanting to be part of HIV prevention efforts for the benefit of others and contributing to new knowledge. Eight participants (28%) highlighted extrinsic motivations, including personal health benefits and financial benefits. Most participants noted these extrinsic benefits in conjunction with the intrinsic benefits, while just two participants (7%) mentioned only extrinsic benefits as their motivations for enrolling. The analysis reveals that early-phase trial participation was shaped predominantly by intrinsic motivations, such as contributing to scientific knowledge, personal growth and community responsibility, underscoring the importance of recognising participants' values in trial design and engagement.