Background
With advances in HIV prevention, understanding factors that promote uptake of novel PrEP agents, including social networks, could be critical to increasing coverage and interrupting HIV transmission in vulnerable populations, such as men who have sex with men (MSM).
Methods
We conducted a network-based online survey among MSM and transgender women (TGW) in Baltimore, MD that included PrEP use and preferences. Participants provided data on recent sexual partners and close MSM/TGW friends, who were referred to complete the survey, allowing us to map sexual and social networks using a sociometric design. We constructed networks integrating reported ties and referral patterns, applying fuzzy matching to identify cross-linkages. Logistic regression assessed network associations between the proportion of ties ever taking PrEP and individual PrEP use, as well as the influence of network members’ preferences on personal preference for long-acting injectable PrEP (LA PrEP) — nodes with unknown PrEP status or HIV-positivity, were excluded.
Results
The network (Figure) comprised 149 survey participants recruited Apr–Aug 2024; 93% were cisgender men, 3% TGW, and 4% non-binary; median age was 34; 51% were Black, and 20% reported Hispanic/Latino ethnicity; 55% ever took PrEP. They reported 406 additional contacts and 594 ties (65% social, 35% sexual). Adjusting for sociodemographics, each five-percentage-point increase in the proportion of ties on PrEP raised an individual’s odds of ever taking PrEP by 10% (AOR: 1.10; 95% CI: 1.05 – 1.16), equating to 5.3 times greater odds when one’s entire network is on PrEP. When ties were stratified by relationship, a significant association was only observed in the proportion of close friends on PrEP and not sexual partners. In univariable models of LA PrEP preference, network member preference was one of the strongest correlates, with an individual’s odds of preferring LA PrEP increasing by almost three times when all their ties preferred LA PrEP (OR: 2.75; 95% CI: 1.24 – 6.13). This association was attenuated and no longer statistically significant after adjusting for education or PrEP knowledge.
Conclusions
Social networks, specifically close friends more than sexual partners, may play a key role in an individual’s PrEP use. With LA PrEP, education and knowledge play a critical role in shaping PrEP choice. Interventions to enhance PrEP uptake should consider prioritizing PrEP literacy alongside peer-based approaches to empower informed choices about PrEP.