Marion Saville

Measuring human papillomavirus (HPV) vaccination coverage and the role of the National HPV Vaccination Program Register, Australia

Accurate estimates of HPV vaccination coverage are critical for determining the proportion of the target female population that is not protected by the vaccine, as well as for monitoring the performance of vaccine delivery programs. The implementation of an HPV vaccination register, either as part of an existing immunisation register or stand-alone, can add substantial benefits to an HPV vaccination program. In Australia, the National HPV Vaccination Program Register supports the HPV vaccination program by providing information to consumers and providers about incomplete courses as well as estimates of vaccination coverage by age and area. Future monitoring of vaccine effectiveness will be facilitated by cross-linking to Pap test registries.

Human Papillomavirus and Cervical Cancer in Australasia and Oceania: Risk-factors, Epidemiology and Prevention

The region encompassing Australasia and Oceania, including Australia, New Zealand, Fiji and Papua New Guinea, is a diverse one with respect to ethnicities, cultures and behaviours. It includes countries with comprehensive cervical cytology screening programmes which can be credited with significant reductions in cervical cancer incidence and mortality, and countries with no prevention programmes and significantly higher incidence and mortality. As elsewhere in the world, human papillomavirus (HPV)-16 and 18 are the commonest high-risk types, with the highest rates in women under 25 years of age. These two high-risk HPV types are found most frequently in cervical cancers and high-grade dysplasias, although there are minimal data for many countries in Oceania. In April 2007, Australia became the first country worldwide to commence a government funded universal HPV vaccine programme. The school-based programme targets 12-year old females in an ongoing schedule, with a catch-up programme up to 26 years of age, to be completed in mid-2009. Vaccine introduction has been comprehensively rolled out, with around 75% uptake of the complete vaccine schedule among school-girls in the first year of this initiative. This represents a successful model for other countries. We present data on cervical cancer, risk factors and prevention strategies, including epidemiology of HPV and HPV vaccine strategies.

Human papillomavirus (HPV) vaccination coverage in young Australian women is higher than previously estimated: Independent estimates from a nationally representative mobile phone survey

BACKGROUND Accurate estimates of coverage are essential for estimating the population effectiveness of human papillomavirus (HPV) vaccination. Australia has a purpose built National HPV Vaccination Program Register for monitoring coverage, however notification of doses administered to young women in the community during the national catch-up program (2007-2009) was not compulsory. In 2011, we undertook a population-based mobile phone survey of young women to independently estimate HPV vaccination coverage. METHODS Randomly generated mobile phone numbers were dialed to recruit women aged 22-30 (age eligible for HPV vaccination) to complete a computer assisted telephone interview. Consent was sought to validate self reported HPV vaccination status against the national register. Coverage rates were calculated based on self report and weighted to the age and state of residence structure of the Australian female population. These were compared with coverage estimates from the register using Australian Bureau of Statistics estimated resident populations as the denominator. RESULTS Among the 1379 participants, the national estimate for self reported HPV vaccination coverage for doses 1/2/3, respectively, weighted for age and state of residence, was 64/59/53%. This compares with coverage of 55/45/32% and 49/40/28% based on register records, using 2007 and 2011 population data as the denominators respectively. Some significant differences in coverage between the states were identified. 20% (223) of women returned a consent form allowing validation of doses against the register and provider records: among these women 85.6% (538) of self reported doses were confirmed. CONCLUSIONS We confirmed that coverage rates for young women vaccinated in the community (at age 18-26 years) are underestimated by the national register and that under-notification is greater for second and third doses. Using 2011 population estimates, rather than estimates contemporaneous with the program rollout, reduces register-based coverage estimates further because of large population increases due to immigration since the program.

Improvement in protection against adenocarcinoma of the cervix resulting from participation in cervical screening.

The incidence of adenocarcinoma of the cervix did not decline in Western countries in the 1970s and 1980s despite the availability and use of cervical cytologic screening. The impact of improved endocervical sampling and better recognition of the cytologic precursors to adenocarcinoma during the 1990s in reducing the risk of adenocarcinoma is currently unknown.

Effectiveness of less than three doses of quadrivalent human papillomavirus vaccine against cervical intraepithelial neoplasia when administered using a standard dose spacing schedule: Observational cohort of young women in Australia

Background Optimised two-dose human papillomavirus (HPV) vaccine schedules are now endorsed for young adolescents by the World Health Organization. Limited data are available about effectiveness of <3 doses using a standard dose schedule. Methods Deterministic data linkage was undertaken between the Victorian Cervical Cytology Registry and National HPV Vaccination Program Register to determine quadrivalent HPV vaccination status and incidence of cervical pathology among vaccine eligible women (aged 26 years or younger in 2007) screened in Victoria, Australia between April 2007 and December 2011. Proportional hazards regression was used to estimate hazard ratios (HR) adjusted for age, socioeconomic status and area of residence. Women were stratified into those vaccinated before or after first screen. Results Any number of doses (1, 2 or 3) were associated with lower rates of high grade and low grade cytology diagnoses as long as doses were given before screening commencement (one dose HR high grade 0.44 (95% CI 0.32–0.59), one dose low grade 0.48 (95% CI 0.40–0.58); two doses HR high grade 0.63 (95% CI 0.50–0.80), HR low grade 0.52 (95% CI 0.44–0.61); three doses HR high grade 0.53 (95% CI 0.47–0.60), HR low grade 0.73 (95% CI 0.68–0.78)). Three doses of vaccine, but not fewer, were associated with reduced risk of high grade histologically confirmed abnormality in this cohort, regardless of whether vaccination occurred before or after screening (HR before 0.71 (95% CI 0.64–0.80), HR after 0.87 (95% CI 0.82–0.93)). Secondary analyses censoring end points occurring within 1, 6, 12, or 24 months of final vaccine dose suggested an increasing effect of partial vaccination courses over time. Conclusion Our data suggest that less than three doses of quadrivalent HPV vaccine provides some protection against cervical intraepithelial neoplasia, even when measured within 5 years in a population including those who were sexually active at the time of vaccination.

Cervical screening rates for women vaccinated against human papillomavirus.

Objective: To compare cervical screening rates for women vaccinated with a quadrivalent human papillomavirus (HPV) vaccine with those for unvaccinated women, to address concerns that vaccinated women may not be participating in cervical screening.

Primary HPV testing versus cytology-based cervical screening in women in Australia vaccinated for HPV and unvaccinated: effectiveness and economic assessment for the National Cervical Screening Program

BACKGROUND Australias National Cervical Screening Program currently recommends cytological screening every 2 years for women aged 18-69 years. Human papillomavirus (HPV) vaccination was implemented in 2007 with high population coverage, and falls in high-grade lesions in young women have been reported extensively. This decline prompted a major review of the National Cervical Screening Program and new clinical management guidelines, for which we undertook this analysis. METHODS We did effectiveness modelling and an economic assessment of potential new screening strategies, using a model of HPV transmission, vaccination, natural history, and cervical screening. First, we evaluated 132 screening strategies, including those based on cytology and primary HPV testing. Second, after a recommendation was made to adopt primary HPV screening with partial genotyping and direct referral to colposcopy of women positive for HPV16/18, we evaluated the final effect of HPV screening after incorporating new clinical guidelines for women positive for HPV. Both evaluations considered both unvaccinated and vaccinated cohorts. FINDINGS Strategies entailing HPV testing every 5 years and either partial genotyping for HPV16/18 or cytological co-testing were the most effective. One of the most effective and cost-effective strategies comprised primary HPV screening with referral of women positive for oncogenic HPV16/18 direct to colposcopy, with reflex cytological triage for women with other oncogenic types and direct referral for those in this group with high-grade cytological findings. After incorporating detailed clinical guidelines recommendations, this strategy is predicted to reduce cervical cancer incidence and mortality by 31% and 36%, respectively, in unvaccinated cohorts, and by 24% and 29%, respectively, in cohorts offered vaccination. Furthermore, this strategy is predicted to reduce costs by up to 19% for unvaccinated cohorts and 26% for cohorts offered vaccination, compared with the current programme. INTERPRETATION Primary HPV screening every 5 years with partial genotyping is predicted to be substantially more effective and potentially cost-saving compared with the current cytology-based screening programme undertaken every 2 years. These findings underpin the decision to transition to primary HPV screening with partial genotyping in the Australian National Cervical Screening Program, which will occur in May, 2017. FUNDING Department of Health, Australia.

Home‐based HPV self‐sampling improves participation by never‐screened and under‐screened women: Results from a large randomized trial (iPap) in Australia

We conducted a randomized controlled trial to determine whether HPV self‐sampling increases participation in cervical screening by never‐ and under‐screened (not screened in past 5 years) women when compared with a reminder letter for a Pap test. Never‐ or under‐screened Victorian women aged 30–69 years, not pregnant and with no prior hysterectomy were eligible. Within each stratum (never‐screened and under‐screened), we randomly allocated 7,140 women to self‐sampling and 1,020 to Pap test reminders. The self‐sampling kit comprised a nylon tipped flocked swab enclosed in a dry plastic tube. The primary outcome was participation, as indicated by returning a swab or undergoing a Pap test; the secondary outcome, for women in the self‐sampling arm with a positive HPV test, was undergoing appropriate clinical investigation. The Roche Cobas® 4800 test was used to measure presence of HPV DNA. Participation was higher for the self‐sampling arm: 20.3 versus 6.0% for never‐screened women (absolute difference 14.4%, 95% CI: 12.6–16.1%, p < 0.001) and 11.5 versus 6.4% for under‐screened women (difference 5.1%, 95% CI: 3.4–6.8%, p < 0.001). Of the 1,649 women who returned a swab, 45 (2.7%) were positive for HPV16/18 and 95 (5.8%) were positive for other high‐risk HPV types. Within 6 months, 28 (62.2%) women positive for HPV16/18 had colposcopy as recommended and nine (20%) had cytology only. Of women positive for other high‐risk HPV types, 78 (82.1%) had a Pap test as recommended. HPV self‐sampling improves participation in cervical screening for never‐ and under‐screened women and most women with HPV detected have appropriate clinical investigation.

Measuring effectiveness of the cervical cancer vaccine in an Australian setting (the VACCINE study)

BackgroundThe quadrivalent human papillomavirus vaccine has been provided in Australia through the National Human Papillomavirus Vaccination Program since April 2007. National registry data demonstrates good coverage of the vaccine, with 73% of school-aged girls having received all three doses. To evaluate the effectiveness of the program, we propose a two-pronged approach. In one (sub study A), the prevalence of the vaccine-targeted human papillomavirus genotypes in a population cohort is being estimated, and will be analysed in relation to vaccination status, cervical cytology screening status, demographic, social, behavioural, medical and clinical factors. In sub study B, the distribution of human papillomavirus genotypes detected in high grade cervical intraepithelial neoplastic lesions from vaccine eligible women is being assessed.Methods/DesignSub Study A involves the recruitment of 1569 women aged 18–25, residing in Victoria, Australia, through Facebook advertising. Women who are sexually active are being asked to provide a self-collected vaginal swab, collected at home and posted into the study centre, where human papillomavirus DNA detection and genotyping is performed. Participants also complete an online questionnaire regarding sexual history, experience with, knowledge of, and attitudes towards human papillomavirus, the human papillomavirus vaccine, and cervical screening.Sub Study B will involve the collection of 500 cervical biopsies, positively identified as containing high grade cervical intraepithelial neoplastic lesions and/or adenocarcinoma in situ. Five serial sections are being taken from each case: sections 1 and 5 are being assessed to confirm the presence of the high grade cervical intraepithelial neoplastic lesions or adenocarcinoma in situ; human papillomavirus genotyping is performed on sections 2 and 3; single lesions are excised from section 4 using laser capture microdissection to specifically define causality of a human papillomavirus genotyping of each specific lesion.DiscussionAustralia is well placed to gain a clear and early insight into the effectiveness of the human papillomavirus vaccine in reducing the prevalence of human papillomavirus infection in young women, and any subsequent reduction in the prevalence of pre-cancerous cervical lesions, specifically high grade cervical intraepithelial neoplasia lesions, particularly of vaccine related types. The findings of a successful population based human papillomavirus program will have wide-reaching translational benefits across the globe.

Mobile phones are a viable option for surveying young Australian women: a comparison of two telephone survey methods

BackgroundHouseholds with fixed-line telephones have decreased while mobile (cell) phone ownership has increased. We therefore sought to examine the feasibility of recruiting young women for a national health survey through random digit dialling mobile phones.MethodsTwo samples of women aged 18 to 39 years were surveyed by random digit dialling fixed and mobile numbers. We compared participation rates and responses to a questionnaire between women surveyed by each contact method.ResultsAfter dialling 5,390 fixed-lines and 3,697 mobile numbers, 140 and 128 women were recruited respectively. Among women contacted and found to be eligible, participation rates were 74% for fixed-lines and 88% for mobiles. Taking into account calls to numbers where eligibility was unknown (e.g. unanswered calls) the estimated response rates were 54% and 45% respectively. Of women contacted by fixed-line, 97% reported having a mobile while 61% of those contacted by mobile reported having a fixed-line at home. After adjusting for age, there were no significant differences between mobile-only and fixed-line responders with respect to education, residence, and various health behaviours; however compared to those with fixed-lines, mobile-only women were more likely to identify as Indigenous (OR 4.99, 95%CI 1.52-16.34) and less likely to live at home with their parents (OR 0.09, 95%CI 0.03-0.29).ConclusionsRandom digit dialling mobile phones to conduct a health survey in young Australian women is feasible, gives a comparable response rate and a more representative sample than dialling fixed-lines only. Telephone surveys of young women should include mobile dialling.