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.

Anal squamous cell carcinomas are predominantly associated with high-risk human papillomaviruses (HPVs), particularly HPV 16, similar to cervical, vaginal and vulvar cancers. Although the presence of "low-risk" HPVs, in particular genotypes 6 and 11, have occasionally been reported in various HPV-related anogenital cancers, the overall distribution of these genotypes in the anal canal and perianal tissue may differ to that in the cervix. In addition, although the majority of anal and perianal cancers are associated with HPV, some are not; hence, confirmation of direct association of the virus within a lesion is important. Using laser capture microdissection, anal and perianal invasive carcinomas and high-grade squamous intraepithelial lesions (HSILs) in biopsies previously associated with HPV 6 or 11 alone were isolated from tissue sections and HPV genotype tested. Of seven cases tested, four invasive carcinomas were positive for HPV 6 only, one invasive carcinoma was negative for HPV and two HSILs were positive for HPV 11 only. All samples were confirmed as HPV 16/18 negative using two different DNA targets (E6 and L1). From these results, we confirm that HPV 6 and 11 can occasionally be associated with high-grade lesion and anal cancer.The rate of anal squamous cell carcinoma (SCC) has been steadily increasing in Australia since the mid-1980s in both men and women, and 90% of cases are associated with human papillomavirus (HPV) infection.1 At greatest risk of developing anal SCC are sexually active homosexual men who demonstrate very high rates of HPV infection, HIV-positive individuals, women with previous HPV-related anogenital disease and solid-organ transplant recipients. 2,3A limited number of studies on HPV genotypes potentially associated with anal SCC in Australia 4 have shown similar results to studies conducted in Europe, Asia and the United States, 5-7 which indicate that 70-90% of intra-anal SCC in men are associated with "high-risk" HPV genotypes (HRHPV), predominantly HPV 16. The prevalence of "lowrisk" HPV (LRHPV) genotypes has also occasionally been reported. 6 A study of 110 Australian cases of anal SCC who underwent HPV genotyping (Hillman, personal communication) identified HPV 6 and/or 11 infections in the absence of other HPV genotypes in nine (8.5%) cases; significantly higher than estimates of up to 1% of cervical cancers associated only with HPV 6 or 11.8 Genotypes 6 and 11, although common at anogenital sites, 2 are considered to be low risk for development of carcinoma, as based on studies of cervical SCC. 8 The prevalence of HPV 6 and/or 11 in the anal canal of men who have sex with men (MSM) has been shown to