A modeling study of pre-exposure prophylaxis to eliminate HIV in Taiwan by 2030

The necessity of pre-exposure prophylaxis (PrEP) for ending the global AIDS epidemic by 2030 remains controversial. In Taiwan, the HIV epidemic predominantly affects young, sexually active men who have sex with men (MSM). This study aimed to model the impact and cost-effectiveness of a high-coverage oral emtricitabine/tenofovir PrEP program in Taiwan from an HIV elimination perspective.

We applied stochastic and risk/age-structured deterministic modeling to assess the impact of PrEP scale-up on the basic reproduction number (R₀) and the trajectory of the HIV epidemic in Taiwan, respectively. Both models were parameterized using the national HIV registry and cascade data. Cost-effectiveness was evaluated from a societal perspective.

Here we show that an intensive HIV test-and-treat strategy targeting HIV-positive individuals alone would substantially decrease HIV transmission but is not sufficient to eliminate the HIV epidemic among MSM at the estimated mixing level. In contrast, a PrEP program covering 50% of young, sexually active, high-risk, HIV-negative MSM would suppress HIV's R₀ below 1, facilitating its elimination. It would also reduce HIV incidence to levels below the World Health Organization's HIV elimination threshold (1/1000 person-years) by 2030 and is highly cost-saving, yielding a benefit-cost ratio of 7.16. The program's effectiveness and cost-effectiveness remain robust even under conditions of risk compensation (i.e., no condom use among PrEP users), imperfect adherence (75%), or low-level emtricitabine/tenofovir resistance (1%).

Our findings strongly support scaling up PrEP for young, sexually active, high-risk, HIV-negative MSM as a critical strategy to end the HIV epidemic in Taiwan and globally.