Effectiveness Of Human Papillomavirus (HPV) Vaccination Against Penile Hpv Infection In Men Who Have Sex With Men And Transgender Women.

BACKGROUND In the United States, HPV vaccination has been recommended since 2011 for males aged 11-12 years, with catch-up vaccination recommended through age 26 years for previously unvaccinated men who have sex with men (MSM). METHODS During 2016-2018, a cross-sectional study enrolled MSM and transgender women aged 18-26 years in Seattle, Washington. Participants submitted self-collected penile swab specimens for HPV genotyping. HPV vaccination history was self-reported. We compared HPV prevalence among vaccinated participants versus participants with no/unknown vaccination history using log-binomial regression to estimate adjusted prevalence ratios (aPR) and confidence intervals (CI). RESULTS Among 687 participants, 348 (50.7%) self-reported ever receiving ≥1 HPV vaccine dose; median age at first HPV vaccination was 21 years and median age at first sex was 17 years. Overall, prevalence of penile quadrivalent HPV vaccine (4vHPV)-type HPV was similar in vaccinated participants (12.1%) and participants with no/unknown vaccination (15.6%) (aPR=0.69, 95%CI:0.47-1.01). However, prevalence was significantly lower in participants vaccinated at age ≤18 years than in participants with no/unknown vaccination (aPR=0.15, 95%CI:0.04-0.62), corresponding to a vaccine effectiveness of 85% against 4vHPV-type HPV. CONCLUSIONS Results suggest HPV vaccination is effective in preventing penile HPV infections in young MSM when administered at age ≤18 years.