Very Low Prevalence of Vaccine Human Papillomavirus Types Among 18- to 35-Year Old Australian Women 9 Years Following Implementation of Vaccination

Prevalence of quadrivalent vaccine-targeted HPV types has declined by 92% among women aged 18–35. Strong herd protection, and the effectiveness of less than 3 doses of the vaccine, have likely contributed to the size of these reductions. Abstract Introduction A quadrivalent human papillomavirus vaccination program targeting females aged 12–13 years commenced in Australia in 2007, with catch-up vaccination of 14–26 year olds through 2009. We evaluated the program’s impact on HPV prevalence among women aged 18–35 in 2015. Methods HPV prevalence among women aged 18–24 and 25–35 was compared with prevalence in these age groups in 2005–2007. For women aged 18–24, we also compared prevalence with that in a postvaccine study conducted in 2010–2012. Results For the 2015 sample, Vaccination Register-confirmed 3-dose coverage was 53.3% (65.0% and 40.3% aged 18–24 and 25–35, respectively). Prevalence of vaccine HPV types decreased from 22.7% (2005–2007) and 7.3% (2010–2012), to 1.5% (2015) (P trend < .001) among women aged 18–24, and from 11.8% (2005–2007) to 1.1% (2015) (P = .001) among those aged 25–35. Conclusions This study, reporting the longest surveillance follow-up to date, shows prevalence of vaccine-targeted HPV types has continued to decline among young women. A substantial fall also occurred in women aged 25–35, despite lower coverage. Strong herd protection and effectiveness of less than 3 vaccine doses likely contributed to these reductions.