Vaccine Effectiveness Against 12-Month Incident and Persistent Anal Human Papillomavirus Infection Among Gay, Bisexual, and Other Men Who Have Sex With Men.

Background Real-world evidence of human papillomavirus (HPV) vaccine effectiveness (VE) against longitudinal outcomes is lacking among gay, bisexual, and other men who have sex with men (GBM). We compared 12-month incidence and persistence of anal HPV infection between vaccinated and unvaccinated GBM. Methods We recruited GBM aged 16–30 years in Montreal, Toronto, and Vancouver, Canada, from 2017 to 2019. Participants were followed over a median of 12 months (interquartile range, 12–13 months). Participants self-reported HPV vaccination and self-collected anal specimens for HPV DNA testing. We calculated prevalence ratios (PR) for 12-month cumulative incidence and persistence with ≥1 quadrivalent vaccine type (HPV 6/11/16/18) between vaccinated (≥1 dose at baseline) and unvaccinated participants using a propensity score-weighted, modified Poisson regression. Results Among 248 participants, 109 (44.0%) were vaccinated at baseline, of whom 62.6% received 3 doses. PRs for HPV 6/11/16/18 were 0.56 (95% confidence interval [CI],.24–1.31) for cumulative incidence and 0.53 (95% CI,.25–1.14) for persistence. PRs were 0.23 (95% CI,.05–1.03) and 0.08 (95% CI,.01–.59) for incidence and persistence, respectively, among participants who received their first dose at age ≤23 years and 0.15 (95% CI,.03–.68) and 0.12 (95% CI,.03–.54) among participants who were sexually active for ≤5 years before vaccination. Conclusions Findings support national recommendations for HPV vaccination at younger ages or soon after sexual debut. [ABSTRACT FROM AUTHOR]