Human Papillomavirus Prevalence in Unvaccinated Heterosexual Men After a National Female Vaccination Program

Abstract

Background: In Australia, high uptake of the quadrivalent human papillomavirus (4vHPV) vaccine has led to reductions in the prevalence of human papillomavirus (HPV) genotypes 6, 11, 16, and 18 in women and girls aged ≤25 years. We evaluated the impact of the program impact on HPV prevalence in unvaccinated male subjects.

Methods: Sexually active heterosexual male subjects aged 16-35 years were recruited in 2014-2016. Participants provided a self-collected penile swab sample for HPV genotyping (Roche Linear Array) and completed a demographic and risk factor questionnaire.

Results: The prevalence of 4vHPV genotypes among 511 unvaccinated male subjects was significantly lower in those aged ≤25 than in those aged >25 years: 3.1% (95% confidence interval, 1.5%-5.7%) versus 13.7% (8.9%-20.1%), respectively (P < .001); adjusted prevalence ratio, 0.22 (.09-.51; P < .001). By contrast, the prevalence of high-risk HPV genotypes other than 16 and 18 remained the same across age groups: 16.8% (95% confidence interval, 12.6%-21.9%) in men aged ≤25 years and 17.9% (12.4%-25.0%) in those aged >25 years (P = .76); adjusted prevalence ratio, 0.98, (.57-1.37; P = .58).

Conclusions: A 78% lower prevalence of 4vHPV genotypes was observed among younger male subjects. These data suggest that unvaccinated men may have benefited from herd protection as much as women from a female-only HPV vaccination program with high coverage.

Keywords: HPV; herd effects; herd protection; heterosexual; human papillomavirus; males; prevalence; vaccine.