Health impact and cost effectiveness of implementing gender-neutral HPV vaccination in Japan

OBJECTIVE

To assess the public health impact and cost effectiveness of gender-neutral vaccination (GNV) versus female-only vaccination (FOV) with human papillomavirus (HPV) vaccination in Japan.

METHODS

We modeled the public health impact and cost effectiveness of GNV versus FOV to prevent HPV-associated diseases in Japan over the next 100 years. We used one-way sensitivity analyses to examine the impact of varying key model input parameters and conducted scenario analyses to explore the effects of varying the vaccination coverage rate (VCR) of each cohort.

RESULTS

In the base-case analysis, GNV averted additional cancer cases (17,228 female/6,033 male) and deaths (1,892 female/1,849 male) compared to FOV. When all HPV-associated diseases were considered, GNV had an incremental cost-effectiveness ratio of ¥4,732,320 (US$35,987)/quality-adjusted life year gained compared to FOV. The model was most sensitive to the discount rate and the disutility associated with HPV-related diseases. GNV had greater relative public health benefits when the female VCR was lower and was cost effective at a female VCR of 30%.

CONCLUSIONS

Immediate implementation of GNV would reduce the disease burden and mortality associated with HPV in Japan, and would be cost effective compared to FOV if the female VCR remains low (30%).

Knowledge, Perceptions and Attitudes Toward HPV Vaccination: A Survey on Parents of Girls Aged 11–18 Years Old in Greece

Objective

To investigate knowledge, perceptions and practices of parents of girls aged 11–18 years old in Greece toward HPV vaccination, and determine which factors are associated with parents' decision to vaccinate their daughters.

Methods

A close-end questionnaire was constructed and telephone interviews were conducted upon informed consent. The sample was random, national, stratified by geographic region and representative of the general population of parents of girls aged 11–18. The data collected include: general knowledge, attitudes and perceptions concerning HPV and HPV vaccine, information regarding their daughters' HPV vaccination, and sociodemographic characteristics. Statistical analysis included descriptives and a logistic regression model to investigate which factors are associated with HPV vaccination.

Results

Overall, 1,000 parents participated in the study, 99.4% of which knew what HPV is and 98.8% knew there is a vaccine available against HPV. Furthermore, 47% of the parents stated that their daughters had been vaccinated against HPV, while further analysis revealed that only 35% had received all the recommended doses. In the logistic regression analysis, the following variables had a statistically significant association with HPV vaccination: perceived ease of contracting HPV (OR = 1.105), level of trust in medical profession regarding information on prevention (OR = 1.205), overall perception regarding importance of children's vaccination (OR = 0.618), internet/social media as a source of parent information regarding HPV (OR = 0.886), participant (parent) age (OR = 1.125), and daughter's treating physician's recommendation for HPV vaccination (OR = 7.319).

Conclusions

HPV vaccination coverage is still suboptimal. Comprehension of the obstacles toward this goal is important and the role of healthcare professionals is crucial to increase acceptance.

Economic evaluation of human papillomavirus vaccination in the Global South: a systematic review

OBJECTIVES

Many reviews have been conducted on the economic evaluation of the HPV vaccine in global north countries. But there is a dearth of such reviews in the Global South countries. Hence, this systematic review aims to summarize studies done in these countries.

METHODS

Four databases PubMed, Embase, Cochrane Library, and Google Scholar from 2009 to 2019 were searched for economic evaluations on HPV vaccination in the Global South countries. PRISMA guidelines were followed to include full-text articles. 40 original articles were shortlisted for full-text review.

RESULTS

Studies had varied models, assumptions, and results according to different scenarios. Most studies concluded HPV vaccination to be cost-effective under varied scenarios and vaccine cost was the most influential parameter affecting the sensitivity analyses, consequently incremental cost-effectiveness ratio. A wide range in the cost-effectiveness ratio was observed in the included studies due to different study settings, populations, and inconsistencies in modeling practices (variations in methodological approaches).

CONCLUSIONS

This review suggests the introduction of HPV vaccination alone or in combination with screening according to different countries. The price of the vaccine should be economical and funds for the vaccine should be provided by public sector firms.

HPV-FRAME: A consensus statement and quality framework for modelled evaluations of HPV-related cancer control

Intense research activity in HPV modelling over this decade has prompted the development of additional guidelines to those for general modelling. A specific framework is required to address different policy questions and unique complexities of HPV modelling. HPV-FRAME is an initiative to develop a consensus statement and quality-based framework for epidemiologic and economic HPV models. Its development involved an established process. Reporting standards have been structured according to seven domains reflecting distinct policy questions in HPV and cancer prevention and categorised by relevance to a population or evaluation. Population-relevant domains are: 1) HPV vaccination in pre-adolescent and young adolescent individuals; 2) HPV vaccination in older individuals; 3) targeted vaccination in men who have sex with men; 4) considerations for individuals living with HIV and 5) considerations for low- and middle-income countries. Additional considerations applicable to specific evaluations are: 6) cervical screening or integrated cervical screening and HPV vaccination approaches and 7) alternative vaccine types and alternative dosing schedules. HPV-FRAME aims to promote the development of models in accordance with an explicit framework, to better enable target audiences to understand a model's strength and weaknesses in relation to a specific policy question and ultimately improve the model's contribution to informed decision-making.

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General modelling guidelines are insufficient for reporting HPV models.

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HPV-FRAME is an initiative to develop a quality-based framework for HPV models.

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The framework has seven domains consisting of distinct reporting standards.

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HPV-FRAME aims to promote transparency and improve the quality in reporting.

HPV-vaccination and cancer cervical screening in 53 WHO European Countries: An update on prevention programs according to income level

Human papillomavirus (HPV) is the most common sexually transmitted disease in the world. The aim of our study is to describe the differences in HPV‐vaccination coverage and screening programs in WHO European Countries notably according to income levels. Multiple correspondence analysis was applied to examine the association among the following variables: Gross National Income (GNI) levels (Lower‐Middle Income, LMI; Upper‐Middle Income, UMI; and High Income, HI); type of CC screening program (coverage; opportunistic/organized); vaccination payment policies (free or partial or total charge); mortality rates/100 000 (≤3; >3‐6; >6‐9; >9); incidence rates/100 000 (≤7; >7‐15; >15‐21; >21). Data HPV‐vaccination start (years) (2006‐2008; 2009‐2011; 2012‐2014; >2014; no program); coverage HPV‐vaccination percentage (≤25; 26‐50; 51‐75; >75); data screening start (years) (<1960; 1960‐1980; 1981‐2000; >2000); primary screening test (HPV, cytology), and screening coverage percentage (≤25; >25‐50; >50‐75; >75). A high income is associated with: start of screening before 1960, medium‐high screening coverage, organized screening, start of vaccination in the periods 2009‐2011 and 2012‐2014 and high immunization coverage. On the other hand, lower‐middle income is associated with: late start of vaccination and screening programs with cytology as primary test, high mortality and incidence rates and lower‐medium vaccination coverage. Our results show a useful scenario for crucial support to public health decision‐makers. Public health authorities should monitor the HPV‐vaccinated population in order to determine more precisely the effects on short‐ and long‐term incidence and mortality rates. In fact, the greater the vaccination coverage, the greater will be the efficacy of the program for the prevention of CC and other HPV‐related diseases.

Model Comparisons of the Effectiveness and Cost-Effectiveness of Vaccination: A Systematic Review of the Literature

OBJECTIVES

To describe all published articles that have conducted comparisons of model-based effectiveness and cost-effectiveness results in the field of vaccination. Specific objectives were to 1) describe the methodologies used and 2) identify the strengths and limitations of the studies.

METHODS

We systematically searched MEDLINE and Embase databases for studies that compared predictions of effectiveness and cost-effectiveness of vaccination of two or more mathematical models. We categorized studies into two groups on the basis of their data source for comparison (previously published results or new simulation results) and performed a qualitative synthesis of study conclusions.

RESULTS

We identified 115 eligible articles (only 5% generated new simulations from the reviewed models) examining the effectiveness and cost-effectiveness of vaccination against 14 pathogens (69% of studies examined human papillomavirus, influenza, and/or pneumococcal vaccines). The goal of most of studies was to summarize evidence for vaccination policy decisions, and cost-effectiveness was the most frequent outcome examined. Only 33%, 25%, and 3% of studies followed a systematic approach to identify eligible studies, assessed the quality of studies, and performed a quantitative synthesis of results, respectively. A greater proportion of model comparisons using published studies followed a systematic approach to identify eligible studies and to assess their quality, whereas more studies using new simulations performed quantitative synthesis of results and identified drivers of model conclusions. Most comparative modeling studies concluded that vaccination was cost-effective.

CONCLUSIONS

Given the variability in methods used to conduct/report comparative modeling studies, guidelines are required to enhance their quality and transparency and to provide better tools for decision making.

Human papillomavirus vaccination and the role of herd effects in future cancer control planning: a review

INTRODUCTION

Vaccine herd effects are the indirect protection that vaccinated persons provide to those who remain susceptible to infection, due to the reduced transmission of infections. Herd effects have been an important part of the discourse on how to best implement human papillomavirus (HPV) vaccines and prevent HPV-related diseases.

AREAS COVERED

In this paper, we review the theory of HPV vaccine herd effects derived from mathematical models, give an account of observed HPV vaccine herd effects worldwide, and examine the implications of vaccine herd effects for future cervical cancer screening efforts.

EXPERT COMMENTARY

HPV vaccine herd effects improve the cost-effectiveness of vaccinating preadolescent girls, but contribute to making gender-neutral vaccination less economically efficient. Vaccination coverage and sexual mixing patterns by age are strong determinants of herd effects. Many countries worldwide are starting to observe reductions in HPV-related outcomes likely attributable to herd effects, most notably declining anogenital warts in young men, and declining HPV-16/18 infection prevalence in young unvaccinated women. Policy makers making recommendations for cervical cancer screening will have to consider HPV vaccination coverage and herd effects, as these will affect the positive predictive value of screening and the risk of cervical cancer in unvaccinated women.

Tumour virus vaccines: hepatitis B virus and human papillomavirus

Two of the most important human oncogenic viruses are hepatitis B virus (HBV) and human papillomavirus (HPV). HBV infection has been preventable by vaccination since 1982; vaccination of neonates and infants is highly effective, resulting already in decreased rates of new infections, chronic liver disease and hepato-cellular carcinoma. Nonetheless, HBV remains a global public health problem with high rates of vertical transmission from mother to child in some regions. Prophylactic HPV vaccines composed of virus-like particles (VLPs) of the L1 capsid protein have been licensed since 2006/2007. These target infection by the oncogenic HPVs 16 and 18 (the cause of 70% of cervical cancers); a new vaccine licensed in 2014/2015 additionally targets HPVs 31, 33, 45, 52, 58. HPV vaccines are now included in the national immunization programmes in many countries, with young adolescent peri-pubertal girls the usual cohort for immunization. Population effectiveness in women is now being demonstrated in countries with high vaccine coverage with significant reductions in high-grade cervical intra-epithelial neoplasia (a surrogate for cervical cancer), genital warts and vaccine HPV type genoprevalence. Herd effects in young heterosexual men and older women are evident. Cancers caused by HBV and HPV should, in theory, be amenable to immunotherapies and various therapeutic vaccines for HPV in particular are in development and/or in clinical trial.This article is part of the themed issue 'Human oncogenic viruses'.

A Behavioral Economic Approach to Improving Human Papillomavirus Vaccination

PURPOSE

The objectives of this study were to measure the impact of a behavioral economic intervention on human papillomavirus (HPV) vaccine initiation and series completion rates for adolescents and to measure the impact of the intervention on the receipt of a nonincentivized influenza vaccine.

METHODS

We conducted a quasi-randomized trial to compare the impact of an escalating delayed cash incentive (intervention), compared with usual care (control), on HPV vaccination initiation and series completion rates among adolescents (11-17 years) at an urban medical center. We measured HPV vaccine initiation and completion rates during the 12 months after enrollment and subsequent influenza vaccination rates for 24 months after enrollment.

RESULTS

A total of 85 participants were actively enrolled in the intervention arm and 103 were passively enrolled in the control arm. Participants were predominantly publically insured African-American and Hispanic adolescents. The majority (75%) of the intervention group received one or more doses of the HPV vaccine, with 36% completing the three-dose series, compared with 47% of the control group receiving one or more doses and only 13% completing the series. The odds of HPV p-value vaccine initiation (odds ratio 4.19 [95% confidence interval 1.84-10.10], p < .01) and HPV vaccine series completion (OR 4.16 [95% confidence interval 1.64-11.28], p < .01) were greater among the intervention group compared with the control group. There was no difference in influenza vaccination rates between the intervention group and the control group during the 2013-2014 season (p = .138) and during the 2014-2015 influenza season (p value .683).

CONCLUSIONS

An incentive-based approach to HPV vaccination was effective in increasing vaccine initiation and series dose completion.

Long-Lasting Increased Risk of Human Papillomavirus–Related Carcinomas and Premalignancies After Cervical Intraepithelial Neoplasia Grade 3: A Population-Based Cohort Study

Purpose

The aim of this study was to determine the risk of human papillomavirus (HPV)–related carcinomas and premalignancies in women diagnosed with cervical intraepithelial neoplasia grade 3 (CIN3). Knowledge of this risk is important to preventing the development and progression of other HPV-related premalignancies and carcinomas, by considering prophylactic HPV vaccination and/or by paying increased attention to other HPV-related carcinomas and premalignancies when CIN3 is identified.

Methods

Women diagnosed with a CIN3 between 1990 and 2010 were identified from the Dutch nationwide registry of histopathology and cytopathology (PALGA) and matched with a control group of women without CIN3. Subsequently, all cases of high-risk (hr) HPV–associated high-grade lesions and carcinomas in the anogenital region and oropharynx between 1990 and 2015 were extracted. Incidence rate ratios were estimated for carcinomas and premalignancies of the vulva, vagina, anus, and oropharynx.

Results

A total of 178,036 women were identified: 89,018 with a previous diagnosis of CIN3 and 89,018 matched control subjects without a history of CIN3. Women with a history of CIN3 showed increased risk of HPV-related carcinomas and premalignancies, with incidence rate ratios of 3.85 (95% CI, 2.32 to 6.37) for anal cancer, 6.68 (95% CI, 3.64 to 12.25) for anal intraepithelial neoplasia grade 3, 4.97 (95% CI, 3.26 to 7.57) for vulvar cancer, 13.66 (93% CI, 9.69 to 19.25) for vulvar intraepithelial neoplasia grade 3, 86.08 (95% CI, 11.98 to 618.08) for vaginal cancer, 25.65 (95% CI, 10.50 to 62.69) for vaginal intraepithelial neoplasia grade 3, and 5.51 (95% CI, 1.22 to 24.84) for oropharyngeal cancer. This risk remained significantly increased, even after long-term follow-up of up to 20 years.

Conclusion

This population-based study shows a long-lasting increased risk for HPV-related carcinomas and premalignancies of the anogenital and oropharyngeal region after a CIN3 diagnosis. Studies that investigate methods to prevent this increased risk in this group of patients, such as intensified screening or vaccination, are warranted.

A Multiple Streams analysis of the decisions to fund gender-neutral HPV vaccination in Canada

In Canada, the human papillomavirus (HPV) vaccine is licensed and recommended for females and males. Although all Canadian jurisdictions fund school-based HPV vaccine programs for girls, only six jurisdictions fund school-based HPV vaccination for boys. The research aimed to analyze the factors that underpin government decisions to fund HPV vaccine for boys using a theoretical policy model, Kingdon's Multiple Streams framework. This approach assesses policy development by examining three concurrent, but independent, streams that guide analysis: Problem Stream, Policy Stream, and Politics Stream. Analysis from the Problem Stream highlights that males are affected by HPV-related diseases and are involved in transmitting HPV infection to their sexual partners. Policy Stream analysis makes clear that while the inclusion of males in HPV vaccine programs is suitable, equitable, and acceptable; there is debate regarding cost-effectiveness. Politics Stream analysis identifies the perspectives of six different stakeholder groups and highlights the contribution of government officials at the provincial and territorial level. Kingdon's Multiple Streams framework helps clarify the opportunities and barriers for HPV vaccine policy change. This analysis identified that the interpretation of cost-effectiveness models and advocacy of stakeholders such as citizen-advocates and HPV-affected politicians have been particularly important in galvanizing policy change.

Ecological validity of cost-effectiveness models of universal HPV vaccination: A systematic literature review

BACKGROUND

The protective (herd) effect of the selective vaccination of pubertal girls against human papillomavirus (HPV) implies a high probability that one of the two partners involved in intercourse is immunised, hence preventing the other from this sexually transmitted infection. The dynamic transmission models used to inform immunisation policy should include consideration of sexual behaviours and population mixing in order to demonstrate an ecological validity, whereby the scenarios modelled remain faithful to the real-life social and cultural context. The primary aim of this review is to test the ecological validity of the universal HPV vaccination cost-effectiveness modelling available in the published literature.

METHODS

The research protocol related to this systematic review has been registered in the International Prospective Register of Systematic Reviews (PROSPERO: CRD42016034145). Eight published economic evaluations were reviewed.

RESULTS

None of the studies showed due consideration of the complexities of human sexual behaviour and the impact this may have on the transmission of HPV.

DISCUSSION

Our findings indicate that all the included models might be affected by a different degree of ecological bias, which implies an inability to reflect the natural demographic and behavioural trends in their outcomes and, consequently, to accurately inform public healthcare policy. In particular, ecological bias have the effect to over-estimate the preference-based outcomes of selective immunisation. A relatively small (15-20%) over-estimation of quality-adjusted life years (QALYs) gained with selective immunisation programmes could induce a significant error in the estimate of cost-effectiveness of universal immunisation, by inflating its incremental cost effectiveness ratio (ICER) beyond the acceptability threshold. The results modelled here demonstrate the limitations of the cost-effectiveness studies for HPV vaccination, and highlight the concern that public healthcare policy might have been built upon incomplete studies.

Ecological validity of cost-effectiveness models of universal HPV vaccination: a protocol for a systematic review

BACKGROUND

Sexually transmitted infection with high-risk, oncogenic strains of human papillomavirus (HPV) still induces a relevant burden of diseases on both men and women. Although vaccines appear to be highly efficacious in preventing the infection of the most common high-risk strains (HPV 6, 11, 16, 18), important questions regarding the appropriate target population for prophylactic vaccination are still debated. Models in the extant literature seem to converge on the cost-effectiveness of high coverage (>80%) of a single cohort of 12-year-old girls. This vaccination strategy should provide an adequate level of indirect protection (herd immunity) to the unvaccinated boys. This argument presupposes the ecological validity of the cost-effectiveness models; the implicit condition that the characteristics of the individuals and the sexual behaviours observed in the models is generalisable to the natural behaviours of the population. The primary aim of this review is to test the ecological validity of the cost-effectiveness models of universal HPV vaccination available in the literature. The ecological validity of each model will be defined by the number of representative characteristics and behaviours taken into consideration.

METHODS

Nine bibliographic databases will be searched: MEDLINE (via PubMed); Scopus; Science Direct; EMBASE via OVID SP, Web of Science, DARE, NHIR EED and HTA (via NHIR CRD); and CINHAL Plus. An additional search for grey literature will be conducted on Google Scholar and Open Grey. A search strategy will be developed for each of the databases. Data will be extracted following a pre-determined spreadsheet and then clustered and prioritised: the main outcomes will report the inputs to the demographic and epidemiological model, while additional outcomes will refer to basic inputs to the cost-effectiveness valuation. Each study included in the review will be scored by the number of representative characteristics and behaviours taken into consideration (yes or no) on both dimensions. Individual study's scores will be plotted in a 2 by 2 matrix: studies included in the upper right quadrant will be defined as ecologically valid, since which both individuals' characteristics and their sexual behaviours are representative.

DISCUSSION

The proposed systematic review will be the first to assess the ecological validity of cost-effectiveness studies. In the context of sexually transmitted diseases, when this condition is violated, an error in predicting the protective impact of herd immunity would occur. Hence, a vaccination policy informed on ecologically invalid models would potentially expose boys to a residual risk of contracting HPV-induced malignancies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016034145.

Population-level impact, herd immunity, and elimination after human papillomavirus vaccination: a systematic review and meta-analysis of predictions from transmission-dynamic models

BACKGROUND

Modelling studies have been widely used to inform human papillomavirus (HPV) vaccination policy decisions; however, many models exist and it is not known whether they produce consistent predictions of population-level effectiveness and herd effects. We did a systematic review and meta-analysis of model predictions of the long-term population-level effectiveness of vaccination against HPV 16, 18, 6, and 11 infection in women and men, to examine the variability in predicted herd effects, incremental benefit of vaccinating boys, and potential for HPV-vaccine-type elimination.

METHODS

We searched MEDLINE and Embase for transmission-dynamic modelling studies published between Jan 1, 2009, and April 28, 2015, that predicted the population-level impact of vaccination on HPV 6, 11, 16, and 18 infections in high-income countries. We contacted authors to determine whether they were willing to produce new predictions for standardised scenarios. Strategies investigated were girls-only vaccination and girls and boys vaccination at age 12 years. Base-case vaccine characteristics were 100% efficacy and lifetime protection. We did sensitivity analyses by varying vaccination coverage, vaccine efficacy, and duration of protection. For all scenarios we pooled model predictions of relative reductions in HPV prevalence (RRprev) over time after vaccination and summarised results using the median and 10th and 90th percentiles (80% uncertainty intervals [UI]).

FINDINGS

16 of 19 eligible models from ten high-income countries provided predictions. Under base-case assumptions, 40% vaccination coverage and girls-only vaccination, the RRprev of HPV 16 among women and men was 0·53 (80% UI 0·46-0·68) and 0·36 (0·28-0·61), respectively, after 70 years. With 80% girls-only vaccination coverage, the RRprev of HPV 16 among women and men was 0·93 (0·90-1·00) and 0·83 (0·75-1·00), respectively. Vaccinating boys in addition to girls increased the RRprev of HPV 16 among women and men by 0·18 (0·13-0·32) and 0·35 (0·27-0·39) for 40% coverage, and 0·07 (0·00-0·10) and 0·16 (0·01-0·25) for 80% coverage, respectively. The RRprev were greater for HPV 6, 11, and 18 than for HPV 16 for all scenarios investigated. Finally at 80% coverage, most models predicted that girls and boys vaccination would eliminate HPV 6, 11, 16, and 18, with a median RRprev of 1·00 for women and men for all four HPV types. Variability in pooled findings was low, but increased with lower vaccination coverage and shorter vaccine protection (from lifetime to 20 years).

INTERPRETATION

Although HPV models differ in structure, data used for calibration, and settings, our population-level predictions were generally concordant and suggest that strong herd effects are expected from vaccinating girls only, even with coverage as low as 20%. Elimination of HPV 16, 18, 6, and 11 is possible if 80% coverage in girls and boys is reached and if high vaccine efficacy is maintained over time.

FUNDING

Canadian Institutes of Health Research.

Eurogin Roadmap 2015: How has HPV knowledge changed our practice: Vaccines

This review is one of two complementary reviews that have been prepared in the framework of the Eurogin Roadmap 2015 to evaluate how knowledge about HPV is changing practices in HPV infection and disease control through vaccination and screening. In this review of HPV vaccine knowledge, we present the most significant findings of the past year which have contributed to our knowledge of the two HPV prophylactic vaccines currently in widespread use and about the recently licensed nonavalent HPV vaccine. Whereas anal cancer is dealt with in the companion mini-review on screening, we also review here the rapidly evolving evidence regarding HPV-associated head and neck cancer and priority research areas.

Public Health Benefits of Routine Human Papillomavirus Vaccination for Adults in the Netherlands: A Mathematical Modeling Study

BACKGROUND

Expanding routine human papillomavirus (HPV) vaccination to adults could be an effective strategy to improve prevention of HPV infection and cervical cancer.

METHODS

We evaluated the following adult vaccination strategies for women only and for both women and men in addition to the current girls-only vaccination program in the Netherlands, using the established STDSIM microsimulation model: one-time mass campaign, vaccination at the first cervical cancer screening visit, vaccination at sexual health clinics, and combinations of these strategies.

RESULTS

The estimated impact of expanding routine vaccination to adult women is modest, with the largest incremental reductions in the incidence of HPV infection occurring when offering vaccination both at the cervical cancer screening visit and during sexually transmitted infection (STI) consultations (about 20% lower after 50 years for both HPV-16 and HPV-18). Adding male vaccination during STI consultations leads to more-substantial incidence reductions: 63% for HPV-16 and 84% for HPV-18. The incremental number needed to vaccinate among women is 5.48, compared with 0.90 for the current vaccination program.

CONCLUSIONS

Offering vaccination to adults, especially at cervical cancer screening visits (for women) and during STI consultations (for both sexes), would substantially reduce HPV incidence and would be an efficient policy option to improve HPV prevention and subsequently avert cervical and possibly male HPV-related cancers.

Methodological Challenges to Economic Evaluations of Vaccines: Is a Common Approach Still Possible?

Economic evaluation of vaccination is a key tool to inform effective spending on vaccines. However, many evaluations have been criticised for failing to capture features of vaccines which are relevant to decision makers. These include broader societal benefits (such as improved educational achievement, economic growth and political stability), reduced health disparities, medical innovation, reduced hospital beds pressures, greater peace of mind and synergies in economic benefits with non-vaccine interventions. Also, the fiscal implications of vaccination programmes are not always made explicit. Alternative methodological frameworks have been proposed to better capture these benefits. However, any broadening of the methodology for economic evaluation must also involve evaluations of non-vaccine interventions, and hence may not always benefit vaccines given a fixed health-care budget. The scope of an economic evaluation must consider the budget from which vaccines are funded, and the decision-maker's stated aims for that spending to achieve.

HPV vaccines: how many doses are needed for protection?

HPV virus-like particle vaccines are highly immunogenic, well tolerated and are in the national immunization programs in more than 62 countries. Genital HPV is a sexually transmitted infection with first infection occurring just after the onset of sexual activity. The routine cohort for immunization in almost all countries are adolescent girls 9–15 years of age with or without catch-up for older adolescents and young women. In countries with vaccine coverage exceeding 50%, reductions in vaccine type HPV geno-prevalence and disease are being shown. The mechanism of protection is assumed to be via neutralizing antibody. Antibody concentration in adolescents less than 14 years of age after two doses of vaccine at 0 and 6 months are noninferior to women after three doses and in whom efficacy was demonstrated in randomized control trials. The original three-dose schedules have already been reduced in many countries, for those 14 years of age and under, to two doses at least 6 months apart for the licensed vaccines Cervarix® and GARDASIL®. There is preliminary evidence that one dose of vaccine is as effective as two or three doses at preventing persistent HPV infection in the cervix in young women and a one-dose schedule may be possible if supported by evidence from randomized controlled trials.

Update on human papillomavirus vaccination: Where are we now?

Infection with human papillomavirus (HPV) is the major cause of pre-invasive and invasive lesions of the urogenital tract, resulting in morbidity and mortality worldwide. HPV-related infection is responsible for most cases of cervical cancer, a leading cause of cancer death in women worldwide. Developed countries have screening programs in place to detect precancerous lesions at early stages; in resource-limited settings however, HPV related diseases are often identified in advanced stages. This is due to limitations in the availability and roll out of effective screening programs. The relatively recent availability of the HPV vaccine has provided a new public health opportunity to decrease the incidence of HPV-related disease. The high mortality rates seen in developing countries could be reduced through effective implementation of HPV vaccination programs. Large trials have proven the efficacy of bivalent, quadrivalent vaccine and most recently 9-valent vaccine. Uptake in vaccination remains low due to multiple barriers including lack of education, lack of access, and costs. New strategies are being assessed to increase access, increase knowledge and reduce costs that may result in feasible vaccination programs worldwide. The goal of this article is to review the effectiveness and safety of the current HPV vaccines available, vaccine delivery strategies, cost effectiveness, and efforts to improve the acceptability. A literature search was conducted through PubMed using the terms “HPV vaccination, and safety, and males, and acceptability and strategies, and cost effectiveness,”focusing on articles published between 2006 and 2015. The most relevant and larger scale trials were evaluated for discussion.

Impact and Cost-effectiveness of 3 Doses of 9-Valent Human Papillomavirus (HPV) Vaccine Among US Females Previously Vaccinated With 4-Valent HPV Vaccine

BACKGROUND

We estimated the potential impact and cost-effectiveness of providing 3-doses of nonavalent human papillomavirus (HPV) vaccine (9vHPV) to females aged 13-18 years who had previously completed a series of quadrivalent HPV vaccine (4vHPV), a strategy we refer to as "additional 9vHPV vaccination."

METHODS

We used 2 distinct models: (1) the simplified model, which is among the most basic of the published dynamic HPV models, and (2) the US HPV-ADVISE model, a complex, stochastic, individual-based transmission-dynamic model.

RESULTS

When assuming no 4vHPV cross-protection, the incremental cost per quality-adjusted life-year (QALY) gained by additional 9vHPV vaccination was $146 200 in the simplified model and $108 200 in the US HPV-ADVISE model ($191 800 when assuming 4vHPV cross-protection). In 1-way sensitivity analyses in the scenario of no 4vHPV cross-protection, the simplified model results ranged from $70 300 to $182 000, and the US HPV-ADVISE model results ranged from $97 600 to $118 900.

CONCLUSIONS

The average cost per QALY gained by additional 9vHPV vaccination exceeded $100 000 in both models. However, the results varied considerably in sensitivity and uncertainty analyses. Additional 9vHPV vaccination is likely not as efficient as many other potential HPV vaccination strategies, such as increasing primary 9vHPV vaccine coverage.

Vaccination of boys or catch-up of girls above 11 years of age with the HPV-16/18 AS04-adjuvanted vaccine: where is the greatest benefit for cervical cancer prevention in Italy?

Background

Since 2007, a Human Papillomavirus (HPV) vaccination programme against cervical cancer (CC) is implemented in Italy in 11-year-old girls. The extension of HPV vaccination to young adult women, or to 11-year-old boys could further reduce the CC burden, in the latter case from indirect effect on HPV transmission. The objective of the study was to compare the potential CC cases prevention from HPV-16/18 AS04-adjuvanted vaccination of adding catch-up targeting 15- or 25-year-old girls to the addition of boys vaccination in Italy.

The models assessing the impact of these alternative vaccination strategies are usually dynamic models requiring numerous input data. Simpler models could however provide some insight into this question, as reported in the current study.

Methods

A published cohort model adapted to the Italian setting was used to estimate the potential CC reduction following different HPV vaccination strategies with a HPV-16/18 AS04-adjuvanted vaccine: vaccination of 11-year-old girls, female aged 15 or 25 years. The model assumed that the maximum benefit obtained from vaccinating boys equals the CC reduction that would result from immunisation of all non-vaccinated girls of the same age. Each cohort of 11-year-olds (either girls or boys) was assumed to include 281,000 individuals and a 70 % vaccination coverage was applied. Sensitivity analysis was performed by varying the vaccination coverage and the overlap in potential sexual contacts between vaccinated boys and girls of the same age-group.

Results

Under base case, compared with the screening-only scenario, HPV vaccination of 11-year-old girls, 15-year-old females, 25-year-old females or 11-year-old boys, would prevent 1,146, 1,082, 788 or 491 CC cases respectively. HPV vaccination of boys could result in more CC cases prevented than adding a female catch-up only in scenarios with low vaccination coverage in the primary target cohort and when combined with small overlap between vaccinated boys and girls of the same age cohort.

Conclusions

For a fixed limited additional budget allowing the inclusion of a single catch-up cohort, the extension of HPV vaccination to girls or young women instead of boys was estimated to maximise the number of CC cases prevented.

The estimated impact of human papillomavirus vaccine coverage on the lifetime cervical cancer burden among girls currently aged 12 years and younger in the United States

Using a previously published dynamic model, we illustrate the potential benefits of human papillomavirus vaccination among girls currently 12 years or younger in the United States. Increasing vaccine coverage of young girls to 80% would avert 53,300 lifetime cervical cancer cases versus 30% coverage and 28,800 cases versus 50% coverage.

Systematic review of model-based cervical screening evaluations

BACKGROUND

Optimising population-based cervical screening policies is becoming more complex due to the expanding range of screening technologies available and the interplay with vaccine-induced changes in epidemiology. Mathematical models are increasingly being applied to assess the impact of cervical cancer screening strategies.

METHODS

We systematically reviewed MEDLINE®, Embase, Web of Science®, EconLit, Health Economic Evaluation Database, and The Cochrane Library databases in order to identify the mathematical models of human papillomavirus (HPV) infection and cervical cancer progression used to assess the effectiveness and/or cost-effectiveness of cervical cancer screening strategies. Key model features and conclusions relevant to decision-making were extracted.

RESULTS

We found 153 articles meeting our eligibility criteria published up to May 2013. Most studies (72/153) evaluated the introduction of a new screening technology, with particular focus on the comparison of HPV DNA testing and cytology (n = 58). Twenty-eight in forty of these analyses supported HPV DNA primary screening implementation. A few studies analysed more recent technologies - rapid HPV DNA testing (n = 3), HPV DNA self-sampling (n = 4), and genotyping (n = 1) - and were also supportive of their introduction. However, no study was found on emerging molecular markers and their potential utility in future screening programmes. Most evaluations (113/153) were based on models simulating aggregate groups of women at risk of cervical cancer over time without accounting for HPV infection transmission. Calibration to country-specific outcome data is becoming more common, but has not yet become standard practice.

CONCLUSIONS

Models of cervical screening are increasingly used, and allow extrapolation of trial data to project the population-level health and economic impact of different screening policy. However, post-vaccination analyses have rarely incorporated transmission dynamics. Model calibration to country-specific data is increasingly common in recent studies.

Population-level impact and herd effects following human papillomavirus vaccination programmes: a systematic review and meta-analysis

BACKGROUND

Human papillomavirus (HPV) vaccination programmes were first implemented in several countries worldwide in 2007. We did a systematic review and meta-analysis to assess the population-level consequences and herd effects after female HPV vaccination programmes, to verify whether or not the high efficacy reported in randomised controlled clinical trials are materialising in real-world situations.

METHODS

We searched the Medline and Embase databases (between Jan 1, 2007 and Feb 28, 2014) and conference abstracts for time-trend studies that analysed changes, between the pre-vaccination and post-vaccination periods, in the incidence or prevalence of at least one HPV-related endpoint: HPV infection, anogenital warts, and high-grade cervical lesions. We used random-effects models to derive pooled relative risk (RR) estimates. We stratified all analyses by age and sex. We did subgroup analyses by comparing studies according to vaccine type, vaccination coverage, and years since implementation of the vaccination programme. We assessed heterogeneity across studies using I(2) and χ(2) statistics and we did trends analysis to examine the dose-response association between HPV vaccination coverage and each study effect measure.

FINDINGS

We identified 20 eligible studies, which were all undertaken in nine high-income countries and represent more than 140 million person-years of follow-up. In countries with female vaccination coverage of at least 50%, HPV type 16 and 18 infections decreased significantly between the pre-vaccination and post-vaccination periods by 68% (RR 0·32, 95% CI 0·19-0·52) and anogenital warts decreased significantly by 61% (0·39, 0·22-0·71) in girls 13-19 years of age. Significant reductions were also recorded in HPV types 31, 33, and 45 in this age group of girls (RR 0·72, 95% CI 0·54-0·96), which suggests cross-protection. Additionally, significant reductions in anogenital warts were also reported in boys younger than 20 years of age (0·66 [95% CI 0·47-0·91]) and in women 20-39 years of age (0·68 [95% CI 0·51-0·89]), which suggests herd effects. In countries with female vaccination coverage lower than 50%, significant reductions in HPV types 16 and 18 infection (RR 0·50, 95% CI 0·34-0·74]) and in anogenital warts (0·86 [95% CI 0·79-0·94]) occurred in girls younger than 20 years of age, with no indication of cross-protection or herd effects.

INTERPRETATION

Our results are promising for the long-term population-level effects of HPV vaccination programmes. However, continued monitoring is essential to identify any signals of potential waning efficacy or type-replacement.

FUNDING

The Canadian Institutes of Health Research.

Comparison of two dose and three dose human papillomavirus vaccine schedules: cost effectiveness analysis based on transmission model

OBJECTIVE

To investigate the incremental cost effectiveness of two dose human papillomavirus vaccination and of additionally giving a third dose.

DESIGN

Cost effectiveness study based on a transmission dynamic model of human papillomavirus vaccination. Two dose schedules for bivalent or quadrivalent human papillomavirus vaccines were assumed to provide 10, 20, or 30 years' vaccine type protection and cross protection or lifelong vaccine type protection without cross protection. Three dose schedules were assumed to give lifelong vaccine type and cross protection.

SETTING

United Kingdom.

POPULATION

Males and females aged 12-74 years.

INTERVENTIONS

No, two, or three doses of human papillomavirus vaccine given routinely to 12 year old girls, with an initial catch-up campaign to 18 years.

MAIN OUTCOME MEASURE

Costs (from the healthcare provider's perspective), health related utilities, and incremental cost effectiveness ratios.

RESULTS

Giving at least two doses of vaccine seems to be highly cost effective across the entire range of scenarios considered at the quadrivalent vaccine list price of £86.50 (€109.23; $136.00) per dose. If two doses give only 10 years' protection but adding a third dose extends this to lifetime protection, then the third dose also seems to be cost effective at £86.50 per dose (median incremental cost effectiveness ratio £17,000, interquartile range £11,700-£25,800). If two doses protect for more than 20 years, then the third dose will have to be priced substantially lower (median threshold price £31, interquartile range £28-£35) to be cost effective. Results are similar for a bivalent vaccine priced at £80.50 per dose and when the same scenarios are explored by parameterising a Canadian model (HPV-ADVISE) with economic data from the United Kingdom.

CONCLUSIONS

Two dose human papillomavirus vaccine schedules are likely to be the most cost effective option provided protection lasts for at least 20 years. As the precise duration of two dose schedules may not be known for decades, cohorts given two doses should be closely monitored.

Cost-effectiveness of a bivalent human papillomavirus vaccination program in Japan

Background Human papillomavirus (HPV) vaccines and their widespread adoption have the potential to relieve a large part of the burden of cervical cancer morbidity and mortality, particularly in countries that have low screening rates or, like Japan, lack a cohesive universal screening program. An economic evaluation was conducted to assess the cost-effectiveness of introducing a bivalent HPV vaccination program in Japan from a healthcare perspective. Methods: A Markov model of the natural history of HPV infection that incorporates both vaccination and screening was developed for Japan. The modelled intervention, a bivalent HPV vaccine with a 100% lifetime vaccine efficacy and 80% vaccine coverage, given to a cohort of 12-year-old Japanese girls in conjunction with the current screening program, was compared with screening alone in terms of costs and effectiveness. A discount rate of 5% was applied to both costs and utilities where relevant. Results: Vaccination alongside screening compared with screening alone is associated with an incremental cost-effectiveness ratio (ICER) of US$20 315 per quality-adjusted-life-year gained if 80% coverage is assumed. The ICER at 5% coverage with the vaccine plus screening, compared with screening alone, is US$1158. Conclusion: The cost-effectiveness results suggest that the addition of a HPV vaccination program to Japan’s cervical cancer screening program is highly likely to prove a cost-effective way to reduce the burden of cervical cancer, precancerous lesions and HPV16/18-related diseases.

Vaccination against human papilloma virus infection in male adolescents: knowledge, attitudes, and acceptability among parents in Italy

OBJECTIVES

To elicit information about parents' knowledge, attitudes, and acceptability toward HPV infection and vaccination of male adolescents in Italy; to identify subgroups of this population who exhibit poor knowledge about prevention of HPV infection and reveal negative attitudes toward HPV vaccination in relation to their male sons.

STUDY DESIGN

Data were collected via self-administered anonymous questionnaire from 1021 parents of males aged 10 to 14 y who were recruited from a random sample of public secondary schools in the South of Italy.

RESULTS

Three-quarters (72.6%) reported that the vaccine is a preventive measure for HPV infection and 55.8% that condom use reduces the risk of HPV infection. A high education level, abundant sources of information about HPV infection received from physicians, and knowledge about HPV infection were factors significantly associated with high level of knowledge about preventive measures for HPV infection. 71% revealed their intentions to vaccinate their sons, and this intention was significantly associated with perceived benefits both for HPV vaccination for girls and for childhood recommended vaccinations as well as a need for additional information about HPV vaccination. 53.7% of the eligible parents reported that their daughters had been vaccinated against HPV.

CONCLUSION

Results of the study suggest that the risk of acquiring HPV infection and HPV-related diseases is sorely underestimated. Knowledge on the benefits of adolescents' HPV vaccination in cancer prevention in both sexes should be improved to maximize uptake of HPV vaccination.

Development of a quality framework for models of cervical screening and its application to evaluations of the cost-effectiveness of HPV vaccination in developed countries

BACKGROUND

HPV vaccination has now been introduced in most developed countries, but this has occurred in the context of established cervical cancer screening mechanisms which provide population-level protection against the most common HPV-related cancer. Therefore, estimating the cost-effectiveness of HPV vaccination to further reduce HPV-related disease depends in large part on the estimation of the effectiveness of the cervical screening 'background'. The aim of this study was to systematically review and assess methods for simulating cervical screening in decision analytic models used for evaluation of HPV vaccination.

METHODS

Existing quality frameworks for economic models were extended to develop a specific quality framework for models of cervical screening. This involved domains for model structure, parameterisation (data sources) and validation (consistency). A systematic review of economic evaluations of HPV vaccination was then conducted, and assessment of cervical screening model components was then performed via application of the new quality framework.

RESULTS

Generally, models took into account population-level cervical screening participation, but were inconsistent in their approach to modelling abnormal smear management, diagnostic evaluation and treatment of precancerous disease. There was also considerable variability in the accuracy of modelling clinical pathways and the scope of validation performed for screening-related outcomes, with focus directed towards cervical cancer targets. Only a few models comprehensively validated against observed pre-cancerous abnormalities.

CONCLUSION

Models of HPV vaccination in developed countries can be improved by further attention to the 'background' modelling of secondary protection via cervical screening. The quality framework developed for this review can be used to inform future HPV vaccination evaluations, including evaluations of the cost-effectiveness of male vaccination and next generation HPV vaccines, and to assess models used to evaluate new cervical screening technologies and recommendations.

Comparing the cost-effectiveness of two- and three-dose schedules of human papillomavirus vaccination: a transmission-dynamic modelling study

BACKGROUND

Recent evidence suggests that two doses of HPV vaccines may be as protective as three doses in the short-term. We estimated the incremental cost-effectiveness of two- and three-dose schedules of girls-only and girls & boys HPV vaccination programmes in Canada.

METHODS

We used HPV-ADVISE, an individual-based transmission-dynamic model of multi-type HPV infection and diseases (anogenital warts, and cancers of the cervix, vulva, vagina, anus, penis and oropharynx). We conducted the analysis from the health payer perspective, with a 70-year time horizon and 3% discount rate, and performed extensive sensitivity analyses, including duration of vaccine protection and vaccine cost.

FINDINGS

Assuming 80% coverage and a vaccine cost per dose of $85, two-dose girls-only vaccination (vs. no vaccination) produced cost/quality-adjusted life-year (QALY)-gained varying between $7900-24,300. The incremental cost-effectiveness ratio of giving the third dose to girls (vs. two doses) was below $40,000/QALY-gained when: (i) three doses provide longer protection than two doses and (ii) two-dose protection was shorter than 30 years. Vaccinating boys (with two or three doses) was not cost-effective (vs. girls-only vaccination) under most scenarios investigated.

INTERPRETATION

Two-dose HPV vaccination is likely to be cost-effective if its duration of protection is at least 10 years. A third dose of HPV vaccine is unlikely to be cost-effective if two-dose duration of protection is longer than 30 years. Finally, two-dose girls & boys HPV vaccination is unlikely to be cost-effective unless the cost per dose for boys is substantially lower than the cost for girls.

Cost-effectiveness of female human papillomavirus vaccination in 179 countries: a PRIME modelling study

BACKGROUND

Introduction of human papillomavirus (HPV) vaccination in settings with the highest burden of HPV is not universal, partly because of the absence of quantitative estimates of country-specific effects on health and economic costs. We aimed to develop and validate a simple generic model of such effects that could be used and understood in a range of settings with little external support.

METHODS

We developed the Papillomavirus Rapid Interface for Modelling and Economics (PRIME) model to assess cost-effectiveness and health effects of vaccination of girls against HPV before sexual debut in terms of burden of cervical cancer and mortality. PRIME models incidence according to proposed vaccine efficacy against HPV 16/18, vaccine coverage, cervical cancer incidence and mortality, and HPV type distribution. It assumes lifelong vaccine protection and no changes to other screening programmes or vaccine uptake. We validated PRIME against existing reports of HPV vaccination cost-effectiveness, projected outcomes for 179 countries (assuming full vaccination of 12-year-old girls), and outcomes for 71 phase 2 GAVI-eligible countries (using vaccine uptake data from the GAVI Alliance). We assessed differences between countries in terms of cost-effectiveness and health effects.

FINDINGS

In validation, PRIME reproduced cost-effectiveness conclusions for 24 of 26 countries from 17 published studies, and for all 72 countries in a published study of GAVI-eligible countries. Vaccination of a cohort of 58 million 12-year-old girls in 179 countries prevented 690,000 cases of cervical cancer and 420,000 deaths during their lifetime (mostly in low-income or middle-income countries), at a net cost of US$4 billion. HPV vaccination was very cost effective (with every disability-adjusted life-year averted costing less than the gross domestic product per head) in 156 (87%) of 179 countries. Introduction of the vaccine in countries without national HPV vaccination at present would prevent substantially more cases of cervical cancer than in countries with such programmes, although the disparity has narrowed since 2012. If 71 phase 2 GAVI-eligible countries adopt vaccination according to forecasts, then in 2070 GAVI Alliance-funded vaccination could prevent 200,000 cases of cervical cancer and 100,000 deaths in some of the highest-burden countries.

INTERPRETATION

Large between-country disparities exist for HPV vaccination, with countries with the most to gain yet to introduce national HPV vaccination. Support from the GAVI Alliance could help to reduce such disparities, but a substantial burden will remain even after presently projected vaccine introductions.

FUNDING

WHO.

Sociodemographic inequalities in sexual activity and cervical cancer screening: implications for the success of human papillomavirus vaccination

BACKGROUND

Papanicolaou smear screening has significantly reduced cervical cancer morbidity and mortality. However, inequalities still persist across different socioeconomic status (SES) groups. These inequalities have been associated with differential participation in screening. However, even with equal participation to screening, some women may still have greater risk of cervical cancer because of sexual behavior. We aim to identify the sociodemographic characteristics of women who reported greater sexual activity and/or screening underuse.

METHODS

We used data from (i) the Canadian Community Health Survey-2005, a population-based survey of 130,000 Canadians, and (ii) a multicenter study including 952 women screened for cervical cancer.

RESULTS

Aboriginals and women with lower SES reported greater sexual activity and lower screening participation, which may produce synergetic effects toward higher cervical cancer risk. Women who did not complete high school and aboriginals were, respectively, 3.6 and 2.5 times more likely to report sexual debut before 15 years old compared with women with university degree and Caucasians. Women who did not complete high school were 2.2 times more likely to have never been screened compared with women with university degree. East and South Asian women were, respectively, 4.3 and 3.1 times more likely to have never been screened than Canadian-born women but reported lower levels of sexual activity and were adherent to screening guidelines when screened at least once.

CONCLUSIONS

The success of human papillomavirus vaccination at reducing cervical cancer and inequalities will depend on achieving high coverage among high-risk subpopulations.

IMPACT

These groups must be monitored closely, and if need be, targeted for additional interventions.

Human papillomavirus and cervical cancer

Cervical cancer is caused by human papillomavirus infection. Most human papillomavirus infection is harmless and clears spontaneously but persistent infection with high-risk human papillomavirus (especially type 16) can cause cancer of the cervix, vulva, vagina, anus, penis, and oropharynx. The virus exclusively infects epithelium and produces new viral particles only in fully mature epithelial cells. Human papillomavirus disrupts normal cell-cycle control, promoting uncontrolled cell division and the accumulation of genetic damage. Two effective prophylactic vaccines composed of human papillomavirus type 16 and 18, and human papillomavirus type 16, 18, 6, and 11 virus-like particles have been introduced in many developed countries as a primary prevention strategy. Human papillomavirus testing is clinically valuable for secondary prevention in triaging low-grade cytology and as a test of cure after treatment. More sensitive than cytology, primary screening by human papillomavirus testing could enable screening intervals to be extended. If these prevention strategies can be implemented in developing countries, many thousands of lives could be saved.

Comparative cost-effectiveness of the quadrivalent and bivalent human papillomavirus vaccines: a transmission-dynamic modeling study

BACKGROUND

The quadrivalent and bivalent human papillomavirus (HPV) vaccines are now licensed in several countries. We compared the cost-effectiveness of the HPV vaccines to provide evidence for policy decisions.

METHODS

We developed HPV-ADVISE, a multi-type individual-based transmission-dynamic model of HPV infection and disease (anogenital warts, and cervical, anogenital and oropharyngeal cancers). We calibrated the model to sexual behavior and epidemiologic data from Canada, and estimated quality-adjusted life-years (QALYs) lost and costs ($CAN 2010) from the literature. Vaccine-type efficacy was based on a systematic literature review. The analysis was performed from the healthcare provider perspective, and costs and benefits were discounted at 3%. Predictions are presented using the median [10th;90th percentiles] of simulations.

RESULTS

Under base-case assumptions (vaccinating 10-year-old girls, 80% coverage, $95/dose), using the quadrivalent and bivalent vaccines is estimated to cost $15,528 [12,056;19,140] and $20,182 [15,531;25,240] per QALY-gained, respectively. At equal price, the quadrivalent vaccine is more cost-effective than bivalent under all scenarios investigated, except when assuming longer duration of protection for the bivalent and minimal anogenital warts burden. Under base-case assumptions, the maximum additional cost per dose for the quadrivalent vaccine to remain more cost-effective than the bivalent is $32 [17;46] (using a $40,000/QALY-gained threshold). Results were most sensitive to discounting, time-horizon, differences in durations of protection and anogenital warts burden.

CONCLUSIONS

Vaccinating pre-adolescent girls against HPV is predicted to be highly cost-effective. If equally priced, the quadrivalent is the most economically desirable vaccine. However, ultimately, the most cost-effective HPV vaccine will be determined by their relative price.

Cost-effectiveness of human papillomavirus vaccination in low and middle income countries: a systematic review

The World Health Organization recommends establishing that human papillomavirus vaccination is cost-effective before vaccine introduction. We searched Pubmed, Embase and the Cochrane Library to 1 April 2012 for economic evaluations of human papillomavirus vaccination in low and middle income countries. We found 25 articles, but almost all low income countries and many middle income countries lacked country-specific studies. Methods, assumptions and consequently results varied widely, even for studies conducted for the same country. Despite the heterogeneity, most studies conclude that vaccination is likely to be cost-effective and possibly even cost saving, particularly in settings without organized cervical screening programmes. However, study uncertainty could be reduced by clarity about vaccine prices and vaccine delivery costs. The review supports extending vaccination to low income settings where vaccine prices are competitive, donor funding is available, cervical cancer burden is high and screening options are limited.

Vaccinating Girls and Boys with Different Human Papillomavirus Vaccines: Can It Optimise Population-Level Effectiveness?

BACKGROUND

Decision-makers may consider vaccinating girls and boys with different HPV vaccines to benefit from their respective strengths; the quadrivalent (HPV4) prevents anogenital warts (AGW) whilst the bivalent (HPV2) may confer greater cross-protection. We compared, to a girls-only vaccination program with HPV4, the impact of vaccinating: 1) both genders with HPV4, and 2) boys with HPV4 and girls with HPV2.

METHODS

We used an individual-based transmission-dynamic model of heterosexual HPV infection and diseases. Our base-case scenario assumed lifelong efficacy of 100% against vaccine types, and 46,29,8,18,6% and 77,43,79,8,0% efficacy against HPV-31,-33,-45,-52,-58 for HPV4 and HPV2, respectively.

RESULTS

Assuming 70% vaccination coverage and lifelong cross-protection, vaccinating boys has little additional benefit on AGW prevention, irrespective of the vaccine used for girls. Furthermore, using HPV4 for boys and HPV2 for girls produces greater incremental reductions in SCC incidence than using HPV4 for both genders (12 vs 7 percentage points). At 50% vaccination coverage, vaccinating boys produces incremental reductions in AGW of 17 percentage points if both genders are vaccinated with HPV4, but increases female incidence by 16 percentage points if girls are switched to HPV2 (heterosexual male incidence is incrementally reduced by 24 percentage points in both scenarios). Higher incremental reductions in SCC incidence are predicted when vaccinating boys with HPV4 and girls with HPV2 versus vaccinating both genders with HPV4 (16 vs 12 percentage points). Results are sensitive to vaccination coverage and the relative duration of protection of the vaccines.

CONCLUSION

Vaccinating girls with HPV2 and boys with HPV4 can optimize SCC prevention if HPV2 has higher/longer cross-protection, but can increase AGW incidence if vaccination coverage is low among boys.

HPV vaccination programs have not been shown to be cost-effective in countries with comprehensive Pap screening and surgery

Pap screening combined with loop electrosurgical excision procedures (LEEP) is almost 100% effective in preventing cervical cancer mortality yet many countries with these procedures have now implemented broad HPV vaccination programs. HPV vaccines have not been demonstrated to be more effective or safer than Pap screening in the prevention of cervical cancer and Pap screening will still be required even in vaccinated women. The HPV vaccine costs Au$450 per person and it does not protect against ~30% of cancer. This investigation analyses the cost-effectiveness of using the HPV vaccine in countries where Pap screening and surgical procedures have already reduced cervical cancer mortality to very low rates. Cost-effectiveness of vaccination programs is being determined by mathematical models which are founded on many assumptions. It is necessary to examine the rigor of these assumptions to be certain of the health benefits that are predicted. In 2002 scientists concluded that HPV 16 and 18 were the central and independent cause of most cervical cancer. This conclusion was based on molecular technology. If HPV 16 and 18 infections are the central and independent cause of most cervical cancer then the incidence of HPV 16 and 18 should vary with the incidence and mortality of cervical cancer worldwide. This correlation does not exist. It is also observed that the majority of HPV 16/18 infections do not lead to cervical cancer. This indicates that other etiological or ‘risk’ factors are necessary for persistent HPV infection to progress to cancer. The benefits of HPV vaccines have been determined by using pre-cancerous lesions in young women as a surrogate for cervical cancer. This surrogate is found to be inadequate as an end-point for cervical cancer. Clinical trials have only provided speculative benefits for the efficacy of HPV vaccines against cancer and the long-term risks of the vaccine have not been established. Pap screening will still be required in vaccinated women hence HPV vaccination programs are not cost-effective, and may do more harm than good, in countries where regular Pap screening and surgery has already reduced the burden of this disease.

Modeling the impact of quadrivalent HPV vaccination on the incidence of Pap test abnormalities in the United States

BACKGROUND

We present data on Pap test results and HPV prevalence from the HPV Sentinel Surveillance project, a multiyear surveillance project enrolling women from a diverse set of 26 clinics throughout the US from 2003 to 2005. We use mathematical modeling to illustrate the potential timing and magnitude of decreases in Pap test abnormalities in sexually transmitted disease (STD), family planning, and primary care clinics in the US as a result of HPV vaccination.

METHODS

The probability of an abnormal Pap result was based on three factors: (1) infection with HPV 16/18, or both; (2) infection with high-risk HPV types other than HPV 16/18; and (3) infection with HPV 6/11, or both. We estimated the relative reduction in the probability of an abnormal Pap result over the first 25 years of a female-only, quadrivalent HPV vaccination program, compared to a scenario of no HPV vaccination in which the probability of abnormal Pap results was assumed constant.

RESULTS

The probability of an abnormal Pap result ranged from 7.0% for the lowest risk group (those without any high-risk HPV types and without HPV 6/11) to 45.2% for the highest risk group (those with HPV 16/18 and at least one other high-risk HPV type). Estimated reductions in abnormal Pap results among women in the 21- to 29-year age group were 0.8%, 10.2%, and 11.3% in years 5, 15, and 25 of the vaccine program respectively, in the lower vaccine coverage scenario, and 7.4%, 21.4%, and 22.2%, respectively, in the higher coverage scenario.

CONCLUSIONS

Our results suggest that HPV vaccination will have a discernable impact on the probability of Pap abnormalities, but the timing and magnitude of the reduction will depend substantially on vaccine coverage and the degree of cross-protection against high risk HPV types other than HPV 16/18.

Economic analyses to support decisions about HPV vaccination in low- and middle-income countries: a consensus report and guide for analysts

Low- and middle-income countries need to consider economic issues such as cost-effectiveness, affordability and sustainability before introducing a program for human papillomavirus (HPV) vaccination. However, many such countries lack the technical capacity and data to conduct their own analyses. Analysts informing policy decisions should address the following questions: 1) Is an economic analysis needed? 2) Should analyses address costs, epidemiological outcomes, or both? 3) If costs are considered, what sort of analysis is needed? 4) If outcomes are considered, what sort of model should be used? 5) How complex should the analysis be? 6) How should uncertainty be captured? 7) How should model results be communicated? Selecting the appropriate analysis is essential to ensure that all the important features of the decision problem are correctly represented, but that the analyses are not more complex than necessary. This report describes the consensus of an expert group convened by the World Health Organization, prioritizing key issues to be addressed when considering economic analyses to support HPV vaccine introduction in these countries.

Modeling preventative strategies against human papillomavirus-related disease in developed countries

Over the last 5 years, prophylactic vaccination against human papillomavirus (HPV) in pre-adolescent females has been introduced in most developed countries, supported by modeled evaluations that have almost universally found vaccination of pre-adolescent females to be cost-effective. Studies to date suggest that vaccination of pre-adolescent males may also be cost-effective at a cost per vaccinated individual of ~US$400-500 if vaccination coverage in females cannot be increased above ~50%; but if it is possible, increasing coverage in females appears to be a better return on investment. Comparative evaluation of the quadrivalent (HPV16,18,6,11) and bivalent (HPV16,18) vaccines centers around the potential trade-off between protection against anogenital warts and vaccine-specific levels of cross-protection against infections not targeted by the vaccines. Future evaluations will also need to consider the cost-effectiveness of a next generation nonavalent vaccine designed to protect against ~90% of cervical cancers. The timing of the effect of vaccination on cervical screening programs will be country-specific and will depend on vaccination catch-up age range and coverage and the age at which screening starts. Initial evaluations suggest that if screening remains unchanged, it will be less cost-effective in vaccinated compared to unvaccinated women but, in the context of current vaccines, will remain an important prevention method. Comprehensive evaluation of new approaches to screening will need to consider the population-level effects of vaccination over time. New screening strategies of particular interest include delaying the start age of screening, increasing the screening interval and switching to primary HPV screening. Future evaluations of screening will also need to focus on the effects of disparities in screening and vaccination uptake, the potential effects of vaccination on screening participation, and the effects of imperfect compliance with screening recommendations. This article forms part of a special supplement entitled "Comprehensive Control of HPV Infections and Related Diseases" Vaccine Volume 30, Supplement 5, 2012.

Male genital premalignant dermatoses

The spectrum of conditions affecting the penile skin is varied and ranges from simple, benign dermatoses to premalignant and malignant conditions. Recently, improved understanding of the aetiology and natural history of these conditions has shaped new treatment paradigms and a functional knowledge of dermatology, urology and genitourinary medicine is required to successfully diagnose and treat these men. In this article, we explore the common precancerous states that can lead to penile carcinoma and review the recent advances with regards to the molecular basis for these dermatoses and the treatments that may be most effective for these men.

Population-level impact of the bivalent, quadrivalent, and nonavalent human papillomavirus vaccines: a model-based analysis

BACKGROUND

Bivalent and quadrivalent human papillomavirus (HPV) vaccines are now licensed in several countries. Furthermore, clinical trials examining the efficacy of a nonavalent vaccine are underway. We aimed to compare the potential population-level effectiveness of the bivalent, quadrivalent, and candidate nonavalent HPV vaccines.

METHODS

We developed an individual-based, transmission-dynamic model of HPV infection and disease in a population stratified by age, gender, sexual activity, and screening behavior. The model was calibrated to highly stratified sexual behavior, HPV epidemiology, and cervical screening data from Canada.

RESULTS

Under base case assumptions, vaccinating 12-year-old girls (70% coverage) with the bivalent (quadrivalent) vaccine is predicted to reduce the cumulative incidence of anogenital warts (AGWs) by 0.0% (72.1%), diagnosed cervical intraepithelial neoplasia lesions 2 and 3 (CIN2 and -3) by 51.0% (46.1%), and cervical squamous cell carcinoma (SCC) by 31.9% (30.5%), over 70 years. Changing from a bivalent (quadrivalent) to a nonavalent vaccine is predicted to reduce the cumulative number of AGW episodes by an additional 66.7% (0.0%), CIN2 and -3 episodes by an additional 9.3% (12.5%), and SCC cases by an additional 4.8% (6.6%) over 70 years. Differences in predicted population-level effectiveness between the vaccines were most sensitive to duration of protection and the time horizon of analysis. The vaccines produced similar effectiveness at preventing noncervical HPV-related cancers.

CONCLUSIONS

The bivalent vaccine is expected to be slightly more effective at preventing CIN2 and -3 and SCC in the longer term, whereas the quadrivalent vaccine is expected to substantially reduce AGW cases shortly after the start of vaccination programs. Switching to a nonavalent vaccine has the potential to further reduce precancerous lesions and cervical cancer.