Impact of varying pre-exposure prophylaxis programs on HIV and Neisseria gonorrhoeae transmission among MSM in the Netherlands: A Modeling Study

Background: In 2019, a 5-year pre-exposure prophylaxis (PrEP) program started in the Netherlands, in which up to 8500 men who have sex with men (MSM) can obtain PrEP and 3-monthly consultations with HIV/STI testing. Setting: We assessed the impact of the PrEP program on transmission of HIV and Neisseria gonorrhea (NG) among MSM in the Netherlands and examined prospective variations of the program after 2024. Methods: We used an agent-based model to estimate the effect of the PrEP program. For hypothetical prospective PrEP programs starting in 2024, we varied the capacity (8,500; 12,000; 16,000 participants) and consultation frequency (3-monthly; 6-monthly; 70% 3-monthly and 30% 6-monthly). Results: At a capacity of 8,500 participants and 3-monthly consultations, the PrEP program could lead to 3,140 [95% credible interval (95% CrI): 1,780–4,780] and 27,930 (95% CrI: 14,560–46,280) averted HIV and NG infections, requiring 316,050 (95% CrI: 314,120–317,580) consultations. At a capacity of 16,000 participants, the programs with 3-monthly consultations and 6-monthly consultations could lead to comparable number of averted HIV [3,940 (95% CrI: 2,420–5,460), and 3,900 (2,320–5,630) respectively] and NG infections [29,970 (95% CrI: 15,490–50,350), and 29,960 (95% CrI: 13,610–50,620) respectively], while requiring substantially different number of consultations: 589,330 (95% CrI: 586,240–591,160) and 272,590 (95% CrI: 271,770–273,290), respectively. Conclusions: Continuation of a PrEP program could lead to a substantial reduction in HIV and NG transmission. More infections could be averted if the number of participants is increased. In turn, the consultation frequency could be reduced without reducing the number of averted infections if capacity is increased.