Journal of Infectious Diseases
Volume 206 Issue 11 December 1, 2012
http://www.journals.uchicago.edu/toc/jid/current

EDITORIAL COMMENTARIES
Editor’s choice: Monitoring HPV Vaccine Impact: Early Results and Ongoing Challenges
Susan Hariri and Lauri Markowitz
J Infect Dis. (2012) 206(11): 1633-1635 doi:10.1093/infdis/jis593

(See the Major Article by Tabrizi et al, on pages 1645–51.)

Extract
In this issue of the Journal of Infectious Diseases, Tabrizi and colleagues present new data from Australia on genital human papillomavirus (HPV) infection prevalence in the periods immediately before and after HPV vaccine introduction [1]. Based on cross-sectional studies of women aged 18–24 years who received Papanicolaou screening in selected family planning clinics throughout the country, the authors report a 20% decrease in overall genital HPV prevalence and a more dramatic decrease of 77% in HPV types targeted by the quadrivalent vaccine (HPV types 6, 11, 16, and 18) from the 2 years before (2005–2007) to the 2 years after (2009–2010) the vaccine was widely implemented through a government-funded program. In addition to comparing HPV prevalence trends across periods, Tabrizi et al obtained HPV vaccination history from participants to more directly evaluate the effect of vaccination on HPV prevalence. Their results indicate significantly lower vaccine-type HPV prevalence among vaccinated women in the postvaccine sample (5.0%) compared with both unvaccinated women from the same period (15.8%) and women from the prevaccine period (28.7%). Using the age-adjusted HPV prevalence ratio of vaccinated to unvaccinated women, the authors calculate a vaccine effectiveness of 73% against infection with any of the 4 vaccine types.

Because the major benefit of HPV vaccination—prevention of cervical and other less common HPV-associated cancers—will not be evident for decades, a spectrum of intermediate outcomes are being monitored to assess the early impact of HPV vaccines. Although considered to be the simplest and earliest indicator of vaccine impact, a reduction in HPV vaccine type prevalence may not be sufficient to guide vaccine policy and practices. Therefore, in addition to ongoing HPV type prevalence monitoring, cancer and precancer outcomes as well as HPV-associated genital warts are …

MAJOR ARTICLES AND BRIEF REPORTS
VIRUSES
Editor’s choice: Fall in Human Papillomavirus Prevalence Following a National Vaccination Program
Sepehr N. Tabrizi, Julia M. L. Brotherton, John M. Kaldor, S. Rachel Skinner, Eleanor Cummins, Bette Liu, Deborah Bateson, Kathleen McNamee, Maria Garefalakis, and Suzanne M. Garland
J Infect Dis. (2012) 206(11): 1645-1651 doi:10.1093/infdis/jis590

Abstract
Background. In April 2007, Australia became the first country to introduce a national government-funded human papillomavirus (HPV) vaccination program. We evaluated the program’s impact on genotype-specific HPV infection prevalence through a repeat survey of women attending clinical services.

Methods. HPV genoprevalence in women aged 18–24 years attending family planning clinics in the prevaccine period (2005–2007) was compared with prevalence among women of the same age group in the postvaccine period (2010–2011). The same recruitment and testing strategies were utilized for both sets of samples, and comparisons were adjusted for potentially confounding variables.

Results. The prevalence of vaccine HPV genotypes (6, 11, 16, and 18) was significantly lower in the postvaccine sample than in the  prevaccine sample (6.7% vs 28.7%; P < .001), with lower prevalence observed in both vaccinated and unvaccinated women compared with the prevaccine population (5.0% [adjusted odds ratio, 0.11; 95% confidence interval, 0.06–0.21] and 15.8% [adjusted odds ratio, 0.42; 95% confidence interval, 0.19–0.93], respectively). A slightly lower prevalence of nonvaccine oncogenic HPV genotypes was also found in vaccinated women (30.8% vs 37.6%; adjusted odds ratio, 0.68; 95% confidence interval, 0.46–0.99).

Conclusions. Four years after the commencement of the Australian HPV vaccination program, a substantial decrease in vaccine-targeted genotypes is evident and should, in time, translate into reductions in HPV-related lesions.