Vaccine Effectiveness Against Anal HPV Among Men Who Have Sex With Men Aged 18–45 Years Attending Sexual Health Clinics in 3 United States Cities, 2018–2023

Abstract

Background. We assessed human papillomavirus (HPV) vaccine effectiveness (VE) against anal HPV among men who have sex with men (MSM) in 2018–2023. Methods. Residual anal specimens from MSM without HIV aged 18–45 years were tested for HPV. We calculated adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) for associations between vaccination (≥1 dose) and quadrivalent vaccine (4vHPV)-type prevalence adjusting for city, race/ethnicity, and nonvaccine-type HPV prevalence, stratified by age group (18–26, 27–45 years). VE was calculated as (1 − aPR) × 100. Results. Among 2802 persons aged 18–26, 4vHPV-type prevalence was lower in those vaccinated at age <18 (aPR = 0.13; 95% CI, .08–.22; VE = 87%) and those vaccinated ≥2 years before specimen collection (aPR = 0.52; 95% CI, .42–.64; VE = 48%) compared with unvaccinated persons. Among 3548 persons aged 27–45, 4vHPV-type prevalence was lower in those vaccinated at ages 18–26 (aPR = 0.68; 95% CI, .57–.82; VE = 32%) and those vaccinated ≥2 years before specimen collection (aPR = 0.66; 95% CI, .57–.77; VE = 33%) compared with unvaccinated persons. While we observed no VE in persons vaccinated at age >26 overall, 4vHPV-type prevalence was lower in the subgroup vaccinated ≥2 years before specimen collection (aPR = 0.71; 95% CI, .56–.89; VE = 29%). Conclusions. We found high VE against anal 4vHPV-type prevalence among MSM aged 18–26 who were vaccinated at age <18. Lower VE was observed among MSM aged 27–45 who were vaccinated at age 18–26 or ≥2 years before specimen collection. While ideally vaccination should be given at younger ages, vaccination can prevent some future infections in this population.