Prepped for PrEP? Acceptability, continuation and adherence among men who have sex with men and transgender women enrolled as part of Vietnam's first pre-exposure prophylaxis program

Background: HIV prevalence among men who have sex with men (MSM) and transgender women (TGW) in Vietnam is high, whereas coverage of effective HIV prevention services has been inadequate. Studies have measured MSM and TGW demand for pre-exposure prophylaxis (PrEP) services, which led to the design of the first ever PrEP program in Vietnam, Prepped for PrEP (P4P). Methods: In March 2017, PrEP services were offered in Ho Chi Minh City as part of the P4P demonstration project, enabling same-day enrolment in three key population (KP)-led clinics and four public clinics. P4P aimed to assess acceptability and feasibility of PrEP services through calculating the rate of PrEP enrolment over time, and quarterly measures of continuation and adherence over an 18-month period. Results: A total of 1069 MSM and 62 TGW were enrolled in P4P. Average monthly PrEP enrolment among MSM increased five-fold from the first 3 months (March-June 2017) to the last 3 months of active enrolment (March-June 2018), whereas for TGW, no increased trend in PrEP enrolment per quarter was seen. Self-reported PrEP adherence was >90% at all time points among MSM, but varied from 11.1% to 88.9% among TGW. PrEP continuation was calculated at months 3, 6, 9, 12, 15 and 18. For MSM, it was 88.7% at month 3, 68.8% at month 12 and 46.6% at month 18, whereas for TGW, it was 87.1%, 54.8% and 52.8%, respectively. Multivariable regression identified that MSM with lower-than-average income (adjusted odds ratio (aOR) 2.38 (95% confidence interval (CI): 1.59-3.54), P = 0.000), aged >30 years (aOR 2.03 (95% CI: 1.30-3.40), P = 0.007) and with an increasing number of sex partners (aOR: 1.06 (1.01-1.11), P = 0.011) had greater odds of remaining on PrEP. For TGW, being aged >30 years was associated with continuing on PrEP (aOR 5.62 (95% CI: 1.05-29.9), P = 0.043). Conclusions: We found PrEP to be highly acceptable among MSM and moderately acceptable among TGW. Continuation rates were relatively high for the first roll-out of PrEP; however, those aged <= 30 years were much more likely to discontinue services. Scaling-up PrEP through differentiated and community-led and engaged PrEP service delivery will be key to effectively increase access and uptake over the next 5 years.