Vaccination protects against penile HPV when given in adolescence
HPV vaccination was effective in preventing penile HPV infection in transgender women and men who have sex with men when the vaccine was administered before and up to age 18 years, researchers reported in The Journal of Infectious Diseases.
The study did not find that vaccination was effective against penile HPV when the first dose was administered after age 18 years.
“This observed lack of effectiveness with older age at vaccine administration is likely due to exposure to HPV prior to vaccination, as the reported median age at first HPV vaccine dose (21 years) was greater than the median age at first sex with a partner (17 years) in this study,” Rachel L. Winer, PhD, a professor of epidemiology at the University of Washington School of Public Health, and colleagues wrote.
Winer and colleagues performed a cross-sectional study of men who have sex with men (MSM) and transgender women aged 18 to 26 years in Seattle who submitted self-collected penile swab specimens for HPV genotyping and self-reported their vaccination history from 2016 to 2018. The researchers compared HPV prevalence among vaccinated participants with the prevalence among participants with no or unknown vaccination history.
Overall, 348 of 687 study participants (50.7%) included in the analysis self-reported ever receiving one or more HPV vaccine dose, Winer and colleague said. The mean age of the participants was 23 years old. Most participants reported more than five sex partners, and more than half reported more than 20, according to the study.
The researchers found that the prevalence of penile quadrivalent HPV vaccine (4vHPV)-type HPV was similar among vaccinated participants (12.1%) and participants with no or unknown vaccination (15.6%) (adjusted prevalence ratio [aPR] = 0.69; 95% CI, 0.47-1.01).
However, the prevalence was significantly lower among participants vaccinated at age 18 years or younger than in participants with no or unknown vaccination status (aPR = 0.15; 95% CI, 0.04-0.62) — a vaccine effectiveness of 85% against 4vHPV-type HPV.
According to Winer and colleagues, there were no cases of penile HPV among the 37 participants who received a first HPV vaccine dose before having sex for the first time.
“Our findings contribute real-world data on HPV vaccine effectiveness in MSM and transgender women,” the authors wrote. “Results highlight the importance of routine HPV vaccination in early adolescence, and the need for continued public health efforts to increase adolescent HPV vaccine coverage.”