A descriptive analysis of transgender participants in phase 1-2a trials of the HIV Vaccine Trials Network (HVTN) in the United States and Peru

Abstract

Background: HIV disproportionately impacts transgender populations globally, creating challenges to inclusion in trials requiring low HIV risk profiles (LHRP) for acquisition. Our knowledge of transgender individuals with LHRP is limited. We conducted an analysis of transgender and cisgender individuals in HVTN trials enrolling individuals with LHRP.

Methods: We analyzed data from 694 participants enrolled in the phase 1-2a HVTN trials in the US and Peru from 2009 to 2014 that included individuals who reported gender identity (GI) differing from assigned birth sex (transgender [TG]), and compared them with those who reported a congruent GI (cisgender [CG]).

Results: 681 participants (98%) were CG and 13 (2%) were TG. Mean age was 25 years. 16% were Hispanic and most (69%) were White. Reasons for enrolling included to help find an effective vaccine (TG 100%; CG 98%) and help their community (TG 100%; CG 96%). Significant differences by GI were observed in reported pre-existing conditions (p = 0.004); however, approximately 10% of pre-existing conditions reported by TG were GI-related (e.g., gender dysphoria). Significant differences were observed in hormone therapy use (p < 0.001) and mental health medications (p = 0.007). Retention was excellent with 2.1% missed visits and no discontinuations of vaccination for TG and 3% missed visits and 7.1% discontinuations among CG. There was no statistically significant difference in HIV incidence.

Conclusions: Primary reasons for participation were altruistic for all participants. Comparable to CG counterparts, TG participants maintained LHRP, followed trial procedures, and had high retention, facilitating meaningful early phase HIV preventive vaccine trial contributions.

Keywords: Biomedical interventions; HIV prevention; HIV/AIDS; Transgender; Vaccine clinical trials.