Five-Year German PrEP cohort reveals high HIV protection and persistent STI burden: implications for individualized...

To evaluate adherence patterns, effectiveness, and sexually transmitted infection (STI) incidence among pre-exposure prophylaxis (PrEP) users in Germany and identify strategies to optimize HIV and STI prevention through individualized care and alternative PrEP modalities.

A single-site, pseudonymized prospective cohort study was conducted in Hamburg, Germany from December 2019 to September 2024. Clinical and laboratory data were linked with structured behavioral surveys from PrEP users at the University Medical Center Hamburg-Eppendorf.

Of 980 consented individuals, 589 initiated PrEP (median age 32 years, 97.1% male, and 81.8% were born in Germany). The mean follow-up was 102.3 weeks (IQR: 38.6-151.4), totaling 1189.5 person-years. Daily users averaged 315 days of PrEP coverage per year (IQR: 293.0-361.9 days), whereas on-demand users averaged 219 days (IQR: 138.4-311.6 days), highlighting substantial variability in usage patterns. The overall dropout rate was 46.9%. No cases of HIV occurred during active PrEP use. STI incidence remained high 52.4 /100 PY (95% CI: 47.8-57.4, n = 421) for daily PrEP users, 38.9/100 PY (95% CI: 30.1-49.5, n = 79) for event-driven users, predominantly due to Chlamydia trachomatis (21.1/100 PY) and Neisseria gonorrhoeae (18.8/100 PY). Interest in long-acting PrEP was high (70%), especially among illicit substance users (OR 5.54). Renal function remained stable during follow-up.

PrEP demonstrated high effectiveness despite heterogeneous risk burden and generally stable renal function. This supports flexible, person-centered models with simplified, risk-stratified monitoring and long-acting options. To extend impact beyond MSM, services should add multilingual access and women- and migrant-inclusive outreach.