Quadrivalent human papillomavirus vaccination successfully reduces the prevalence of vaccine-targeted genotypes in a young, vaccine-eligible-age sample of Australian females.

Background The prevalence of genital tract vaccine-type human papillomavirus (HPV) is on the decline due to high vaccine uptake through the national HPV immunisation program in Australia. The aim of this study was to investigate HPV vaccine coverage and factors associated with HPV in a vaccine-eligible sample of young Australian females.
Methods: Females aged 16-25 years were recruited into the Young Female Health Initiative study, a young women's health study, via Facebook advertising from 2012 to 2017. Sexually active participants were asked to provide a self-collected vaginal swab for the detection of HPV DNA; positive samples were genotyped. Self-reported HPV vaccination status was confirmed by the National HPV Vaccination Program Register. Outcomes of the study were HPV acquisition and genotype, HPV vaccination status and factors associated with HPV.
Results: Overall, 22.8% of samples (95% confidence interval (CI) 17.8-27.8%; n = 62/272) were positive for any HPV DNA, of which 19.1% (95% CI 14.4-23.8%; n = 52/272) were oncogenic types. HPV 16 was detected in three samples (1.1%; 95% CI -0.1%, 2.3%; two not HPV vaccinated and one vaccinated after sexual debut). Early sexual debut (<16 years) and multiple sexual partners were independently associated with an increased risk of any HPV.
Conclusions: In a community sample of vaccine-eligible-age females with a high vaccine uptake, the prevalence of vaccine-related HPV genotypes is extremely low. Early sexual debut and multiple sexual partners are positively associated with HPV, underscoring the importance of vaccination at the routinely recommended age of 12-13 years for best vaccine impact.