Preexposure Prophylaxis to Eliminate HIV in Taiwan by 2030: A Modeling Study

Abstract

Preexposure prophylaxis (PrEP) demonstrated 86% efficacy in randomized trials. However, globally, PrEP remains underutilized. The role of PrEP in achieving HIV elimination has been underappreciated and understudied. In Taiwan, the HIV epidemic predominantly affects young, sexually active men who have sex with men (MSM). Our stochastic modeling indicates that the HIV test-and-treat strategy has minimal impact on HIV transmissions that occur during the acute HIV infection. In contrast, a PrEP program providing access to 50% of young, high-risk MSM will halve transmissions during the acute stage and suppress the basic reproduction number (R0) of HIV to below 1, thereby facilitating its elimination. Risk compensation (i.e., none of the PrEP users using condom), imperfect adherence (at 75%), or drug resistance (at a 1% rate) do not undermine such a program's effectiveness. Deterministic modeling further indicates that implementing a 50% coverage PrEP program will reduce the trajectory of the HIV epidemic in Taiwan to below the World Health Organization’s HIV elimination threshold (1/1,000 person-years) by 2030, and such a program is highly cost-saving from a societal perspective, yielding a benefit-cost ratio of 7.16. Our findings strongly support the broad administration of PrEP to high-risk, HIV-negative MSM to achieve HIV elimination by 2030.