Long-acting injection and implant preferences and trade-offs for HIV prevention among South African male youth

BACKGROUND: Long-acting pre-exposure prophylaxis (LA-PrEP) formulated as implants and injections are promising prevention method strategies offering simplicity, discretion, and long dose duration. Men are important end-users of LA-PrEP, and early assessment of their preferences could enhance downstream male engagement in HIV prevention.

METHODS: A discrete-choice experiment (DCE) survey was conducted with 406 men, aged 18-24, in Cape Town, South Africa, to assess preferences for 5 LA-PrEP attributes with 2-4 pictorially-depicted levels: delivery form, duration, insertion location, soreness, and delivery facility. Latent class analysis (LCA) was used to explore heterogeneity of preferences and estimate preference shares.

RESULTS: Median age was 21 (IQR 19-22) and 47% were MSM. Duration was the most important product attribute. LCA identified three classes: "Duration-dominant decision-makers" (46%) were the largest class, defined by significant preference for a longer-duration product. "Comprehensive decision-makers" (36%) had preferences shaped equally by multiple attributes, and preferred implants. "Injection-dominant decision-makers" (18%) had strong preference for injections (vs. implant) and were significantly more likely to be MSM. When estimating shares for a 2-month injection in the buttocks with mild soreness (HPTN regimen) vs. a 6-month implant (to arm) with moderate soreness (current target), 95% of "injection-dominant" would choose injections, whereas 79% and 63% of "duration-dominant" and "comprehensive", would choose implant.

CONCLUSIONS: Young South African men indicated acceptability for LA-PrEP. Preferences were shaped mainly by duration, suggesting a sizeable market for implants, and underscoring the importance of product choice. Further research into men's acceptability of LA PrEP strategies to achieve engagement in these HIV prevention tools constitutes a priority.