Intention to Use Different Formulations of Longer Acting HIV Pre-Exposure Prophylaxis Among Transgender and Gender Expansive Individuals: The Roles of Social Vulnerability and Medical Mistrust.

In 2012, the Federal Drug Administration approved daily oral pre-exposure prophylaxis (PrEP) for HIV prevention in adults. Longer acting injectable PrEP (LA PrEP) has been approved and other formulations are in development. A successful LA PrEP rollout requires examining potential facilitators and barriers to PrEP uptake. Given that transgender and gender expansive (TGE) individuals experience more social vulnerability and higher levels of medical mistrust compared to other populations, examining the role of these two factors in LA PrEP uptake is important. This study, PrEP for ALL, is a community-based participatory research project in Texas that engaged TGE community members and organizational partners through a community advisory board. In total, 482 TGE individuals were recruited and responded to all relevant questions in an online survey, including their intentions to use three formulations: a monthly oral pill, a bimonthly intramuscular injection, and an annual subdermal implant. Multiple regression analysis was used to examine the influence of social vulnerability and medical mistrust on intention to use each LA PrEP formulation adjusting for other relevant factors. Findings suggest that individuals with higher levels of social vulnerability had greater intentions to use the monthly oral pill (β = 0.12, p = 0.009), the bimonthly intramuscular injection (β = 0.18, p < 0.001), and annual subdermal implant (β = 0.17, p < 0.001), whereas medical mistrust reduced intentions to use the bimonthly intramuscular injection (β = -0.18, p < 0.001) and annual subdermal implant (β = -0.11, p = 0.021). Improvements in gender-affirming clinical care are needed along with LA PrEP formulations that allow for greater autonomy and reduced clinical contact. Clinical Trial Registration number: NCT05044286.