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

Computational approaches of modelling human papillomavirus transmission and prevention strategies: a systematic review

Human papillomavirus (HPV) infection is the most common sexually transmitted infection in the world. Persistent oncogenic HPV infection has been a leading threat to global health and can lead to serious complications such as cervical cancer. Prevention interventions including vaccination and screening have been proven effective in reducing the risk of HPV-related diseases. In recent decades, computational epidemiology has been serving as a very useful tool to study HPV transmission dynamics and evaluation of prevention strategies. In this paper, we conduct a comprehensive literature review on state-of-the-art computational epidemic models for HPV disease dynamics, transmission dynamics, as well as prevention efforts. Selecting 45 most-relevant papers from an initial pool of 10,497 papers identified through keyword search, we classify them based on models used and prevention strategies employed, summarize current research trends, identify gaps in the present literature, and identify future research directions. In particular, we describe current consensus regarding optimal prevention strategies which favour prioritizing teenage girls for vaccination. We also note that optimal prevention strategies depend on the resources available in each country, with hybrid vaccination and screening being the most fruitful for developed countries, and screening-only approaches being most cost effective for low and middle income countries. We also highlight that in future, the use of computational and operations research tools such as game theory and linear programming, coupled with the large scale use of census and geographic information systems data, will greatly aid in the modelling, analysis and prevention of HPV.

Persistence of HPV in cervical smears of vaccinated WLWH support for combined molecular testing and cytology screening

BACKGROUND

Human papillomavirus (HPV) infection profoundly affects women living with HIV (WLWH). This infection leads to cervical cancer (CC) and increased mortality.

METHODS

This study monitored HPV infection in WLWH in Rio de Janeiro, Brazil, before (T1) and after (T2) 4 years of vaccination. HPV genotyping and the presence of intraepithelial lesions were investigated at both time points.

RESULTS

Among the 156 WLWH who received the quadrivalent HPV vaccine (4vHPV) at T1, 30 (19.2%) were initially found to have HPV DNA. After vaccination, only three (7%) of those who were HPV-negative at T1 tested positive for HPV. Most women who tested positive for HPV DNA at T1 had normal Pap smear results. However, this cohort also demonstrated a significant increase in cases of atypical squamous cells of uncertain significance and cervical intraepithelial neoplasia in PCR-negative HPV DNA samples at T2 (p < .01). Conversely, women who initially tested negative for HPV DNA continued to exhibit normal Pap smear results in 2018 (p < .01).

CONCLUSIONS

This study highlights the persistence of HPV in WLWH despite vaccination and underscores the importance of continued molecular and cytologic screening. The findings enhance our understanding of vaccine effectiveness in this population and emphasize the need for tailored preventive strategies.

Modelling epidemiological and economics processes - the case of cervical cancer

Different types of mathematical models can be used to forecast the development of diseases as well as associated costs and analyse the cost-effectiveness of interventions. The set of models available to assess these parameters, reach from simple independent equations to highly complex agent-based simulations. For many diseases, it is simple to distinguish between infectious diseases and chronic-degenerative diseases. For infectious diseases, dynamic models are most appropriate because they allow for feedback from the number of infected to the number of new infections, while for the latter Markov models are more appropriate since this feedback is not required. However, for some diseases, the aforementioned distinction is not as clear. Cervical cancer, for instance, is caused by a sexually transmitted virus, and therefore falls under the definition of an infectious disease. However, once infected, the condition can progress to a chronic disease. Consequently, cervical cancer could be considered an infectious or a chronic-degenerative disease, depending on the stage of infection. In this paper, we will analyse the applicability of different mathematical models for epidemiological and economic processes focusing on cervical cancer. For this purpose, we will present the basic structure of different models. We will then conduct a literature analysis of the mathematical models used to predict the spread of cervical cancer. Based on these findings we will draw conclusions about which models can be used for which purpose and which disease. We conclude that each type of model has its advantages and disadvantages, but the choice of model type often seems arbitrary. In the case of cervical cancer, homogenous Markov models seem appropriate if a cohort of newly infected is followed for a shorter period, for instance, to assess the impact of screening programs. For long-term consequences, such as the impact of a vaccination program, a feedback loop from former infections to the future likelihood of infections is required. This can be done using system dynamics or inhomogeneous Markov models. Discrete event or agent-based simulations can be used in the case of cervical cancer when small cohorts or specific characteristics of individuals are required. However, these models require more effort than Markov or System Dynamics models.

Human Papilloma Virus Infection in Men: A Specific Human Virome or a Specific Pathology?

BACKGROUND

Human papillomavirus (HPV) infections in men remain under-researched despite their critical role in disease transmission and the increasing incidence of HPV-related cancers. This study investigates the clinical and molecular characteristics of anogenital HPV infections in men, emphasizing genotype prevalence, diagnostic methods, and lesion variability.

METHODS

A cross-sectional study was conducted on 70 men aged 18-65 years with clinically diagnosed anogenital HPV infection. Lesions were characterized by morphology and location. HPV DNA was analyzed using INNO-LiPA (INNOvative Line Probe Assay), Hybrid Capture II (HC II), and polymerase chain reaction (PCR) assays to determine genotype distribution. Associations between clinical features and HPV genotypes were assessed using multivariate statistical analyses.

RESULTS

Lesions varied in morphology, with verrucous (52.86%) and papular (30%) types being the most common. Localization patterns showed predominance on the penis radix (34.29%) and shaft (27.14%). Molecular testing revealed HPV DNA in 88.57% of the cases using INNO-LiPA, compared to 45% and 40% with HC II and PCR, respectively. Low-risk (LR) genotypes, particularly HPV6, dominated single infections, comprising 68.57% of the cases, while high-risk (HR) genotypes accounted for 20%. Mixed LR and HR infections were observed in 14.29% of the lesions, with greater diversity noted in distal genital regions. Notably, condyloma plana and lesions on the inner prepuce exhibited a higher prevalence of HR and mixed infections. Age and lesion duration showed trends toward older patients and longer disease duration in cases involving perianal and extragenital condylomas, though these findings were not statistically significant. No direct correlation between lesion type or localization and specific genotypes was identified, underscoring the heterogeneity of HPV clinical manifestations in men.

CONCLUSIONS

Anogenital HPV infections in men exhibit significant heterogeneity in lesion morphology, localization, and genotype distribution. HR HPV genotypes were detected in a notable proportion of benign lesions, underscoring their potential role in disease progression. INNO-LiPA proved superior in diagnostic accuracy, highlighting the need for standardized and cost-effective diagnostic approaches for men. Further research is crucial to elucidate HPV's clinical impact in men and inform prevention and treatment strategies.

Advances in HPV-Associated Cervical Cancer Dynamic Modelling for Prevention and Control Evaluation

Cervical cancer is a common malignancy in women, with persistent human papillomavirus (HPV) infection as its primary cause. Understanding the progression from HPV infection to cervical cancer is crucial. Mathematical models play a key role in converting clinical trial data into long-term health forecasts, helping decision-makers tackle challenges posed by limited data and uncertain outcomes. This paper reviews transmission dynamics models and advancements in simulating HPV transmission leading to cervical cancer. It evaluates preventive and control measures, focusing on the impact of HPV vaccination across different vaccine types, doses, age groups, and both genders. These model-based assessments aim to provide insights for developing effective strategies to prevent and control HPV-related cervical cancer.

Effects of different-valent vaccines against human papillomavirus (HPV) to prevent persistent HPV16/18 infections and CIN2+ in women: a systematic review and network meta-analysis

OBJECTIVES

To evaluate the efficacy of 2-valent, 4-valent and 9-valent HPV vaccination in preventing persistent HPV infections and cervical intraepithelial neoplasia grade 2 or higher (CIN2+) lesions among women with different infection statuses at baseline.

METHODS

PubMed, Web of Science, Cochrane, Embase and ClinicalTrials.gov were searched from their inception to March 2024. Randomized controlled trials (RCTs) and post hoc analyses of RCTs reporting the risk of persistent HPV infections and CIN2+ among vaccinated women were included. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to summarize the intervention effects.

RESULTS

Eighteen RCTs and one post hoc analysis of RCTs were included. In the according-to-protocol (ATP) cohorts, the 4-valent vaccine was the most effective against HPV16/18-related persistent infections and CIN2+ (6-month persistent infections (6mPIs): OR 0.05, 95% CI [0.02, 0.15]; 12-month persistent infections (12mPIs): OR 0.02, 95% CI [0.00, 0.18]; CIN2+: OR 0.03 95% CI [0.01, 0.17]). For the total vaccination cohorts (TVCs), the 2-valent vaccine was most effective against HPV16/18-related 12mPIs and CIN2+ (12mPIs: OR 0.15, 95% CI [0.04, 0.63]; CIN2+: OR 0.52 95% CI [0.32, 0.87]), whereas the 4-valent vaccine was most effective against HPV16/18-related 6mPIs (OR 0.08, 95% CI [0.02, 0.28]).

CONCLUSIONS

Vaccination against HPV can significantly reduce the risk of persistent HPV16/18-related infections and CIN2+, regardless of the HPV infection prevaccination. In addition to 4- and 9-valent vaccines, 2-valent vaccines could also provide satisfactory protection against persistent HPV16/18-related infections and CIN2+, especially over the long term, and may constitute an alternative for government-led vaccination programs in developing countries.

Population-level impact of switching to 1-dose human papillomavirus vaccination in high-income countries: examining uncertainties using mathematical modeling

BACKGROUND

A concern in high-income countries is that switching to 1-dose human papillomavirus (HPV) vaccination could cause a rebound in HPV infection and cervical cancer if 1-dose efficacy or duration were inferior to 2 doses. Using mathematical modeling and up-to-date trial-based data, we projected the population-level effectiveness of switching from 2-dose to 1-dose vaccination under different vaccine efficacy and duration assumptions in high-income countries.

METHODS

We used HPV-ADVISE (Agent-based Dynamic model for VaccInation and Screening Evaluation), a transmission-dynamic model of HPV infection and cervical cancer, varying key model assumptions to identify those with the greatest impact on projections of HPV-16 and cervical cancer incidence over time: 1) 1-dose vaccine efficacy and vaccine duration, 2) mechanisms of vaccine efficacy and duration over time, 3) midadult (>30 years of age) sexual behavior, 4) progression to cervical cancer among midadults, and 5) vaccination coverage and programs.

RESULTS

In high-income countries, 1-dose vaccination would cause no appreciable rebound in HPV-16 infection, except for a limited rebound under the most pessimistic assumptions of vaccine duration (average, 25 years), because 1) the switch would occur when HPV prevalence is low because of high 2-dose vaccination coverage and 2) individuals would be protected during their peak ages of sexual activity (<35 to 40 years of age). Our model projects a more limited rebound in cervical cancer because of a shift to older age at infection, resulting in fewer life-years left to potentially develop cancer. Projections were robust when varying key model assumptions.

CONCLUSIONS

High protection during peak ages of sexual activity in high-income countries would likely mitigate any potential rebounds in HPV infection and cervical cancer under the most pessimistic assumptions of 1-dose efficacy and duration.

Gender-Neutral HPV Vaccine in India; Requisite for a Healthy Community: A Review

Human papillomavirus (HPV) affects approximately 80% of individuals, irrespective of gender, and is implicated in various cancers. Existing HPV vaccines, while safe and effective, do not sufficiently protect males when administered solely to females. This review, triggered by the urgent need to address this gap and reduce the associated stigma, aims to evaluate the introduction of a gender-neutral HPV vaccine, GARDASIL-9, in India. The primary objective is to assess the necessity and feasibility of incorporating the gender-neutral HPV vaccine into India's national immunization program. This integration is crucial to ensure equitable access for all children and to mitigate the substantial burden of HPV. A literature search was conducted using databases such as Google Scholar, PubMed, government websites, and relevant publications. Keywords included "gender-neutral vaccine", "HPV vaccine", and "Indian population". The central research question guiding this review is: How necessary and feasible is the inclusion of a gender-neutral HPV vaccine in India's national immunization schedule to ensure equitable access for all children and reduce the HPV burden? The review inclusion criteria comprised studies addressing the prevalence of HPV infections, HPV vaccination awareness among both genders, the cost-effectiveness of gender-neutral vaccines, current HPV vaccination status, and future perspectives specific to India. Studies not meeting these criteria were excluded. The review highlights that introducing a gender-neutral HPV vaccine in India is imperative. Including males in vaccination efforts significantly reduces the overall disease burden and helps in reducing the stigma associated with HPV. A comprehensive vaccination program, bolstered by education and awareness campaigns, and its inclusion in the national immunization schedule is essential. This approach ensures equitable access to the vaccine for all children, fostering a healthier community, preventing HPV-related cancers, and enhancing public health outcomes in India.

HPV Infection Profiles among People Living with HIV and HPV Vaccine Acceptance among Individuals with Different HIV Infection Statuses in China: A Systematic Meta-Analysis

To understand the HPV infection profiles among Chinese HIV/AIDS patients and the HPV vaccine acceptance among unvaccinated Chinese people with different HIV infection statuses after the HPV vaccine launch in China, this study searched Web of Science, PubMed, Cochrane Library, Embase, Scopus, CNKI, WANFANG, SinoMed, and VIP databases up to 23 June 2023, according to the registered protocol (CRD42023449913). A total of 58 studies were included. The results showed that the HPV infection rate among Chinese HIV/AIDS patients was 52.54% (95% CI: 42.11-62.86%) and higher in males than in females (74.55% vs. 41.04%); meanwhile, the rate was higher in the anus than in the cervix (69.22% vs. 41.71%). Although there was no statistical difference, the high-risk HPV infection rate (38.98%) was higher than low-risk HPV (23.86%), and single infections were more common (28.84%) than multiple infections (19.23%). HPV vaccine acceptance among the unvaccinated Chinese population was 59.19% (95% CI: 52.50-65.89%), and was slightly higher among HIV-infected rather than non-HIV-infected individuals (67.72% vs. 59.58%). There was a difference in acceptance among respondents from different regions. Although the difference in acceptance rate between males and females was not statistically significant (61.10% vs. 61.18%), MSM had a higher acceptance rate than non-MSM (84.28% vs. 59.05%). HPV infection is prevalent among HIV patients, demonstrating the need to increase the frequency of HPV screening for PLWH. The HPV vaccine acceptance rate is higher than that of non-HIV-infected individuals. Male acceptance is almost the same as female's, with MSM acceptance higher than non-MSM, suggesting that using MSM, especially MSM in PLWH, as an entry point may be a practical avenue to explore to further expand the scope of HPV vaccination.

Global impact and cost-effectiveness of one-dose versus two-dose human papillomavirus vaccination schedules: a comparative modelling analysis

BACKGROUND

To eliminate cervical cancer as a public health problem, the World Health Organization had recommended routine vaccination of adolescent girls with two doses of the human papillomavirus (HPV) vaccine before sexual initiation. However, many countries have yet to implement HPV vaccination because of financial or logistical barriers to delivering two doses outside the infant immunisation programme.

METHODS

Using three independent HPV transmission models, we estimated the long-term health benefits and cost-effectiveness of one-dose versus two-dose HPV vaccination, in 188 countries, under scenarios in which one dose of the vaccine gives either a shorter duration of full protection (20 or 30 years) or lifelong protection but lower vaccine efficacy (e.g. 80%) compared to two doses. We simulated routine vaccination with the 9-valent HPV vaccine in 10-year-old girls at 80% coverage for the years 2021-2120, with a 1-year catch-up campaign up to age 14 at 80% coverage in the first year of the programme.

RESULTS

Over the years 2021-2120, one-dose vaccination at 80% coverage was projected to avert 115.2 million (range of medians: 85.1-130.4) and 146.8 million (114.1-161.6) cervical cancers assuming one dose of the vaccine confers 20 and 30 years of protection, respectively. Should one dose of the vaccine provide lifelong protection at 80% vaccine efficacy, 147.8 million (140.6-169.7) cervical cancer cases could be prevented. If protection wanes after 20 years, 65 to 889 additional girls would need to be vaccinated with the second dose to prevent one cervical cancer, depending on the epidemiological profiles of the country. Across all income groups, the threshold cost for the second dose was low: from 1.59 (0.14-3.82) USD in low-income countries to 44.83 (3.75-85.64) USD in high-income countries, assuming one dose confers 30-year protection.

CONCLUSIONS

Results were consistent across the three independent models and suggest that one-dose vaccination has similar health benefits to a two-dose programme while simplifying vaccine delivery, reducing costs, and alleviating vaccine supply constraints. The second dose may become cost-effective if there is a shorter duration of protection from one dose, cheaper vaccine and vaccination delivery strategies, and high burden of cervical cancer.

An Updated Analysis of the Impact of HPV Vaccination Based on Long-term Effectiveness in the Netherlands

INTRODUCTION

Vaccination against human papillomavirus (HPV) is considered the most effective strategy to protect women from cervical cancer. Three HPV vaccines are currently licensed in Europe and, although they are generally supported by favorable health economic outcomes, current models fall short in predicting vaccination benefits. Here, we aim to re-evaluate the health benefits of HPV vaccination, using updated long-term effectiveness data and emphasizing quality of life losses related to pre-cancer disease and treatment.

METHODS

We used a static Markov model that compared "only screening" (includes unvaccinated girls) and "vaccination" (assumes 100% vaccination coverage with the bivalent HPV vaccine). A lifetime cohort of 100,000 uninfected 12-year-old girls was included, in which the number of cases with cervical intraepithelial neoplasia grade 2 or higher/3 (CIN2+, CIN3), cervical cancer, and cervical cancer deaths per scenario were determined. Furthermore, the reduction in major excisional procedures, the preterm deliveries averted, and the related gain in quality-adjusted life years (QALYs) due to vaccination were estimated.

RESULTS

The bivalent vaccine showed larger reductions in CIN2+, CIN3, cervical cancer cases, cervical cancer deaths, and major excisional treatments, after including long-term efficacy and effectiveness data, compared to previous data. Moreover, we observed an increased amount of QALYs gained due to prevention of major excisional treatment and the negative side effects related to it.

CONCLUSIONS

Updated health economic models for HPV vaccination, using updated and long-term effectiveness data and including prevention of treatment-related side effects, demonstrate a substantial additional positive effect on vaccination outcomes. Indeed, extrapolation of the bivalent HPV vaccine's updated long-term effectiveness data against HPV-related cervical diseases shows that the positive effects of vaccination may be more substantial than previously estimated. There is a graphical abstract available for this article.

Immunogenicity, safety, and efficacy of the HPV vaccines among people living with HIV: A systematic review and meta-analysis

Background

Vaccines have been demonstrated to protect against high-risk human papillomavirus infection (HPV), including HPV-16/18, and cervical lesions among HIV negative women. However, their efficacy remains uncertain for people living with HIV (PLHIV).We systematically reviewed available evidence on HPV vaccine on immunological, virological, or other biological outcomes in PLHIV.

Methods

We searched five electronic databases (PubMed, Medline and Embase, clinicaltrials.gov and the WHO clinical trial database) for longitudinal prospective studies reporting immunogenicity, virological, cytological, histological, clinical or safety endpoints following prophylactic HPV vaccination among PLHIV. We included studies published by February 11th, 2021. We summarized results, assessed study quality, and conducted meta-analysis and subgroup analyses, where possible.

Findings

We identified 43 publications stemming from 18 independent studies (Ns =18), evaluating the quadrivalent (Ns =15), bivalent (Ns =4) and nonavalent (Ns =1) vaccines. A high proportion seroconverted for the HPV vaccine types. Pooled proportion seropositive by 28 weeks following 3 doses with the bivalent, quadrivalent, and nonavalent vaccines were 0.99 (95% confidence interval: 0.95-1.00, Ns =1), 0.99 (0.98-1.00, Ns =9), and 1.00 (0.99-1.00, Ns =1) for HPV-16 and 0.99 (0.96-1.00, Ns =1), 0.94 (0.91-0.96, Ns =9), and 1.00 (0.99-1.00, Ns =1) for HPV-18, respectively. Seropositivity remained high among people who received 3 doses despite some declines in antibody titers and lower seropositivity over time, especially for HPV-18, for the quadrivalent than the bivalent vaccine, and for HIV positive than negative individuals. Seropositivity for HPV-18 at 29-99 weeks among PLHIV was 0.72 (0.66-0.79, Ns =8) and 0.96 (0.92-0.99, Ns =2) after 3 doses of the quadrivalent and bivalent vaccine, respectively and 0.94 (0.90-0.98, Ns =3) among HIV-negative historical controls. Evidence suggests that the seropositivity after vaccination declines over time but it can lasts at least 2-4 years. The vaccines were deemed safe among PLHIV with few serious adverse events. Evidence of HPV vaccine efficacy against acquisition of HPV infection and/or associated disease from the eight trials available was inconclusive due to the low quality.

Interpretation

PLHIV have a robust and safe immune response to HPV vaccination. Antibody titers and seropositivity rates decline over time but remain high. The lack of a formal correlate of protection and efficacy results preclude definitive conclusions on the clinical benefits. Nevertheless, given the burden of HPV disease in PLHIV, although the protection may be shorter or less robust against HPV-18, the robust immune response suggests that PLHIV may benefit from receiving HPV vaccination after acquiring HIV. Better quality studies are needed to demonstrate the clinical efficacy among PLHIV.

Funding

World Health Organization. MRC Centre for Global Infectious Disease Analysis, Canadian Institutes of Health Research, UK Medical Research Council (MRC).

Reducing Poverty-Related Disparities in Cervical Cancer: The Role of HPV Vaccination

BACKGROUND

Near elimination of cervical cancer in the United States is possible in coming decades, yet inequities will delay this achievement for some populations. We sought to explore the effects of human papillomavirus (HPV) vaccination on disparities in cervical cancer incidence between high- and low-poverty U.S. counties.

METHODS

We calibrated a dynamic simulation model of HPV infection to reflect average counties in the highest and lowest quartile of poverty (percent of population below federal poverty level), incorporating data on HPV prevalence, cervical cancer screening, and HPV vaccination. We projected cervical cancer incidence through 2070, estimated absolute and relative disparities in incident cervical cancer for high- versus low-poverty counties, and compared incidence with the near-elimination target (4 cases/100,000 women annually).

RESULTS

We estimated that, on average, low-poverty counties will achieve near-elimination targets 14 years earlier than high-poverty counties (2029 vs. 2043). Absolute disparities by county poverty will decrease, but relative differences are estimated to increase. We estimate 21,604 cumulative excess cervical cancer cases in high-poverty counties over the next 50 years. Increasing HPV vaccine coverage nationally to the Healthy People 2020 goal (80%) would reduce excess cancer cases, but not alter estimated time to reach the near-elimination threshold.

CONCLUSIONS

High-poverty U.S. counties will likely be delayed in achieving near-elimination targets for cervical cancer and as a result will experience thousands of potentially preventable cancers.

IMPACT

Alongside vaccination efforts, it is important to address the role of social determinants and health care access in driving persistent inequities by area poverty.

Optimal human papillomavirus vaccination strategies to prevent cervical cancer in low-income and middle-income countries in the context of limited resources: a mathematical modelling analysis

Background

Introduction of human papillomavirus (HPV) vaccination has been slow in low-income and middle-income countries (LMICs) because of resource constraints and worldwide shortage of vaccine supplies. To help inform WHO recommendations, we modelled various HPV vaccination strategies to examine the optimal use of limited vaccine supplies and best allocation of scarce resources in LMICs in the context of the WHO global call to eliminate cervical cancer as a public health problem.

Methods

In this mathematical modelling analysis, we developed HPV-ADVISE LMIC, a transmission-dynamic model of HPV infection and diseases calibrated to four LMICs: India, Vietnam, Uganda, and Nigeria. For different vaccination strategies that encompassed use of a nine-valent vaccine (or a two-valent or four-valent vaccine assuming high cross-protection), we estimated three outcomes: reduction in the age-standardised rate of cervical cancer, number of doses needed to prevent one case of cervical cancer (NNV; as a measure of efficiency), and the incremental cost-effectiveness ratio (ICER; in 2017 international $ per disability-adjusted life-year [DALY] averted). We examined different vaccination strategies by varying the ages of routine HPV vaccination and number of age cohorts vaccinated, the population targeted, and the number of doses used. In our base case, we assumed 100% lifetime protection against HPV-16, HPV-18, HPV-31, HPV-33, HPV-45, HPV-52, and HPV-58; vaccination coverage of 80%; and a time horizon of 100 years. For the cost-effectiveness analysis, we used a 3% discount rate. Elimination of cervical cancer was defined as an age-standardised incidence of less than four cases per 100 000 woman-years.

Findings

We predicted that HPV vaccination could lead to cervical cancer elimination in Vietnam, India, and Nigeria, but not in Uganda. Compared with no vaccination, strategies that involved vaccinating girls aged 9–14 years with two doses were predicted to be the most efficient and cost-effective in all four LMICs. NNV ranged from 78 to 381 and ICER ranged from $28 per DALY averted to $1406 per DALY averted depending on the country. The most efficient and cost-effective strategies were routine vaccination of girls aged 14 years, with or without a later switch to routine vaccination of girls aged 9 years, and routine vaccination of girls aged 9 years with a 5-year extended interval between doses and a catch-up programme at age 14 years. Vaccinating boys (aged 9–14 years) or women aged 18 years or older resulted in substantially higher NNVs and ICERs.

Interpretation

We identified two strategies that could maximise efforts to prevent cervical cancer in LMICs given constraints on vaccine supplies and costs and that would allow a maximum of LMICs to introduce HPV vaccination.

Funding

World Health Organization, Canadian Institute of Health Research, Fonds de recherche du Québec–Santé, Compute Canada, PATH, and The Bill & Melinda Gates Foundation.

Translations

For the French and Spanish translations of the abstract see Supplementary Materials section.

Prevalence of cervical HPV infection, sexually transmitted infections and associated antimicrobial resistance in women attending cervical cancer screening in Mali

OBJECTIVES

To assess the prevalence of sexually transmitted infections (STIs), antimicrobial resistance and cervical lesions among women from Sikasso, Mali.

METHODS

Women infected with human immunodeficiency virus (HIV) (n=44) and HIV-negative women (n=96) attending cervical cancer screening were included. Screening for human papillomavirus (HPV), Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) was performed using polymerase chain reaction assays, and herpes simplex virus (HSV-1/2) serological status was assessed using enzyme-linked immunosorbent assays. Antibiotic resistance tests were performed for MG- and NG-positive cases.

RESULTS

A high prevalence of high-risk HPV (hrHPV) infection (63%) was found. This was associated with cervical lesions in 7.5% of cases. An unusual distribution was found, with HPV31, HPV56 and HPV52 being the most prevalent. The hrHPV distribution differed by HIV status, with HIV-positive cases having HPV35/31/51-52-56 and HIV-negative cases having HPV31/56/52. The seroprevalence of HSV-2 was 49%, and the prevalence of other STIs was as follows: CT, 4%; MG, 9%; NG, 1%; and TV, 7%. Five of nine MG-positive specimens and the NG strains obtained were resistant to fluoroquinolone.

CONCLUSIONS

These results showed high prevalence of hrHPV and fluoroquinolone resistance in several NG and MG strains. Further studies are required to confirm these data in Mali, and to improve prevention, screening and management of cervical cancer and other STIs in women.

Differing Age-Specific Cervical Cancer Incidence Between Different Types of Human Papillomavirus: Implications for Predicting the Impact of Elimination Programs

The elimination of cervical cancer rests on high efficacy of human papillomavirus (HPV) vaccines. The HPV type distribution among cases of invasive cervical cancer (ICC) is used to make predictions about the impact of eliminating different types of HPV, but accumulating evidence of differences in age-specific cancer incidence by HPV type exists. We used one of the largest population-based series of HPV genotyping of ICCs (n = 2,850; Sweden, 2002–2011) to estimate age-specific ICC incidence by HPV type and obtain estimates of the cancer-protective impact of the removal of different HPV types. In the base case, the age-specific ICC incidence had 2 peaks, and the standardized lifetime risk (SLTR, the lifetime number of cases per birth cohort of 100,000 females) for HPV-positive ICC was 651 per 100,000 female births. In the absence of vaccine types HPV 16 and HPV 18, the SLTR for ICC was reduced to 157 per 100,000 female births (24% of HPV-positive SLTR). Elimination of all 9 types that can currently be vaccinated against reduced the remaining SLTR to 47 per 100,000 female births (7%), the remaining ICC incidence only slowly increasing with age. In conclusion, after elimination of vaccine-protected HPV types, very few cases of ICC will be left, especially among fertile, reproductive-age women.

Sexually Transmitted Infections Among US Women and Men: Prevalence and Incidence Estimates, 2018

BACKGROUND

The most recent estimates of the number of prevalent and incident sexually transmitted infections (STIs) in the United States were for 2008. We provide updated estimates for 2018 using new methods.

METHODS

We estimated the total number of prevalent and incident infections in the United States for 8 STIs: chlamydia, gonorrhea, trichomoniasis, syphilis, genital herpes, human papillomavirus, sexually transmitted hepatitis B, and sexually transmitted HIV. Updated per-capita prevalence and incidence estimates for each STI were multiplied by the 2018 full resident population estimates to calculate the number of prevalent and incident infections. STI-specific estimates were combined to generate estimates of the total number of prevalent and incident STIs overall, and by sex and age group. Primary estimates are represented by medians, and uncertainty intervals are represented by the 25th (Q1) and 75th (Q3) percentiles of the empirical frequency distributions of prevalence and incidence for each STI.

RESULTS

In 2018, there were an estimated 67.6 (Q1, 66.6; Q3, 68.7) million prevalent and 26.2 (Q1, 24.0; Q3, 28.7) million incident STIs in the United States. Chlamydia, trichomoniasis, genital herpes, and human papillomavirus comprised 97.6% of all prevalent and 93.1% of all incident STIs. Persons aged 15 to 24 years comprised 18.6% (12.6 million) of all prevalent infections; however, they comprised 45.5% (11.9 million) of all incident infections.

CONCLUSIONS

The burden of STIs in the United States is high. Almost half of incident STIs occurred in persons aged 15 to 24 years in 2018. Focusing on this population should be considered essential for national STI prevention efforts.

Estimated Prevalence and Incidence of Disease-Associated Human Papillomavirus Types Among 15- to 59-Year-Olds in the United States

INTRODUCTION

Human papillomavirus (HPV) can cause anogenital warts and several types of cancer, including cervical cancers and precancers. We estimated the prevalence, incidence, and number of persons with prevalent and incident HPV infections in the United States in 2018.

METHODS

Prevalence and incidence were estimated for infections with any HPV (any of 37 types detected using Linear Array) and disease-associated HPV, 2 types that cause anogenital warts plus 14 types detected by tests used for cervical cancer screening (HPV 6/11/16/18/31/33/35/39/45/51/52/56/58/59/66/68). We used the 2013-2016 National Health and Nutrition Examination Survey to estimate prevalence among 15- to 59-year-olds, overall and by sex. Incidences in 2018 were estimated per 10,000 persons using an individual-based transmission-dynamic type-specific model calibrated to US data. We estimated number of infected persons by applying prevalences and incidences to 2018 US population estimates.

RESULTS

Prevalence of infection with any HPV was 40.0% overall, 41.8% in men, and 38.4% in women; prevalence of infection with disease-associated HPV was 24.2% in men and 19.9% in women. An estimated 23.4 and 19.2 million men and women had a disease-associated HPV type infection in 2018. Incidences of any and disease-associated HPV infection were 1222 and 672 per 10,000 persons; incidence of disease-associated HPV infection was 708 per 10,000 men and 636 per 10,000 women. An estimated 6.9 and 6.1 million men and women had an incident infection with a disease-associated HPV type in 2018.

CONCLUSIONS

We document a high HPV burden of infection in the United States in 2018, with 42 million persons infected with disease-associated HPV and 13 million persons acquiring a new infection. Although most infections clear, some disease-associated HPV type infections progress to disease. The HPV burden highlights the need for continued monitoring of HPV-associated cancers, cervical cancer screening, and HPV vaccination to track and prevent disease.

Anal cancer and precancerous lesions: a call for improvement

Anal squamous cell carcinoma is the most common type of anal cancer and is largely associated with anal human papillomavirus infection. The incidence of anal squamous cell carcinoma is increasing, and although still uncommon in the general population, a high incidence has been noted in specific population groups (eg, patients with HIV, men who have sex with men [MSM], recipients of solid organ transplants, women with genital neoplasia, and patients with systemic lupus erythematosus or inflammatory bowel disease). The higher incidence among individuals who are HIV-positive makes anal squamous cell carcinoma one of the most common non-AIDS-defining cancers among HIV-positive individuals. Anal cancer screening in high-risk groups aims to detect high-grade squamous intraepithelial lesions, which are considered anal precancerous lesions, and for which identification can provide an opportunity for prevention. A blind anal cytology is normally the first screening method, and for patients with abnormal results, this approach can be followed by an examination of the anal canal and perianal area under magnification, along with staining-a technique known as high-resolution anoscopy. Digital anorectal examination can enable early anal cancer detection. Several societies are in favour of screening for HIV-positive MSM and recipients of transplants. There are no current recommendations for screening of anal precancerous lesions via endoscopy, but in high-risk groups, a careful observation of the squamocolumnar junction should be attempted. Several treatments can be used to treat high-grade squamous intraepithelial lesions, including argon plasma coagulation or radiofrequency ablation, which are largely limited by high recurrence rates. Gastroenterologists need to be aware of anal squamous cell carcinoma and anal precancerous lesions, given that patients at high risk are frequently encountered in the gastroenterology department. We summarise simple procedures that can help in early anal squamous cell carcinoma detection.

Engaging practices and communities in the development of interventions to promote HPV vaccine uptake: a protocol for implementing Boot Camp Translation in the private practice setting

INTRODUCTION

The Healthy People 2020 report states a goal of 80% uptake of recommended vaccines among adolescents, including the human papillomavirus (HPV) vaccine. However, the rate of uptake of the HPV vaccine is estimated at 51% in 2018, which leaves young people vulnerable to morbidity and mortality from preventable, HPV-related cancers. Reasons for this are multifactorial and include factors at the level of the provider, primary care practice, patient and family, and community. The development of interventions that are responsive to these multifactorial barriers in real-world settings is a priority. Boot Camp Translation (BCT) is a community-engaged approach to message development for translating evidence-based practices into clinics and communities. This project aims to (1) Engage practices and communities in the development of interventions to promote HPV vaccine uptake and (2) Evaluate the impact of the BCT-designed intervention on practice-level HPV vaccine initiation rates. We hypothesise that the BCT-designed intervention will increase the rate of HPV vaccine initiation in the practices.

METHODS AND ANALYSIS

This study will implement HPV-focused BCT in three counties in Colorado with a below average county-level vaccination rate. Each BCT group will design a multipronged intervention targeted at patients, parents, providers and the general community to then be disseminated in the participating practices and communities over the subsequent 6-month period. The long-term goal is to develop a replicable approach and low-cost method of increasing HPV vaccine uptake that is easily adaptable to different settings and sociodemographic contexts.

ETHICS AND DISSEMINATION

This study is approved by the Colorado Multiple Institutional Review Board. Results will be disseminated through peer-reviewed manuscripts and conference presentations, as well as within Colorado practice-based research networks.

TRIAL REGISTRATION NUMBER

NCT04279964.

Impact of HPV vaccination and cervical screening on cervical cancer elimination: a comparative modelling analysis in 78 low-income and lower-middle-income countries

BACKGROUND

The WHO Director-General has issued a call for action to eliminate cervical cancer as a public health problem. To help inform global efforts, we modelled potential human papillomavirus (HPV) vaccination and cervical screening scenarios in low-income and lower-middle-income countries (LMICs) to examine the feasibility and timing of elimination at different thresholds, and to estimate the number of cervical cancer cases averted on the path to elimination.

METHODS

The WHO Cervical Cancer Elimination Modelling Consortium (CCEMC), which consists of three independent transmission-dynamic models identified by WHO according to predefined criteria, projected reductions in cervical cancer incidence over time in 78 LMICs for three standardised base-case scenarios: girls-only vaccination; girls-only vaccination and once-lifetime screening; and girls-only vaccination and twice-lifetime screening. Girls were vaccinated at age 9 years (with a catch-up to age 14 years), assuming 90% coverage and 100% lifetime protection against HPV types 16, 18, 31, 33, 45, 52, and 58. Cervical screening involved HPV testing once or twice per lifetime at ages 35 years and 45 years, with uptake increasing from 45% (2023) to 90% (2045 onwards). The elimination thresholds examined were an average age-standardised cervical cancer incidence of four or fewer cases per 100 000 women-years and ten or fewer cases per 100 000 women-years, and an 85% or greater reduction in incidence. Sensitivity analyses were done, varying vaccination and screening strategies and assumptions. We summarised results using the median (range) of model predictions.

FINDINGS

Girls-only HPV vaccination was predicted to reduce the median age-standardised cervical cancer incidence in LMICs from 19·8 (range 19·4-19·8) to 2·1 (2·0-2·6) cases per 100 000 women-years over the next century (89·4% [86·2-90·1] reduction), and to avert 61·0 million (60·5-63·0) cases during this period. Adding twice-lifetime screening reduced the incidence to 0·7 (0·6-1·6) cases per 100 000 women-years (96·7% [91·3-96·7] reduction) and averted an extra 12·1 million (9·5-13·7) cases. Girls-only vaccination was predicted to result in elimination in 60% (58-65) of LMICs based on the threshold of four or fewer cases per 100 000 women-years, in 99% (89-100) of LMICs based on the threshold of ten or fewer cases per 100 000 women-years, and in 87% (37-99) of LMICs based on the 85% or greater reduction threshold. When adding twice-lifetime screening, 100% (71-100) of LMICs reached elimination for all three thresholds. In regions in which all countries can achieve cervical cancer elimination with girls-only vaccination, elimination could occur between 2059 and 2102, depending on the threshold and region. Introducing twice-lifetime screening accelerated elimination by 11-31 years. Long-term vaccine protection was required for elimination.

INTERPRETATION

Predictions were consistent across our three models and suggest that high HPV vaccination coverage of girls can lead to cervical cancer elimination in most LMICs by the end of the century. Screening with high uptake will expedite reductions and will be necessary to eliminate cervical cancer in countries with the highest burden.

FUNDING

WHO, UNDP, UN Population Fund, UNICEF-WHO-World Bank Special Program of Research, Development and Research Training in Human Reproduction, Canadian Institute of Health Research, Fonds de recherche du Québec-Santé, Compute Canada, National Health and Medical Research Council Australia Centre for Research Excellence in Cervical Cancer Control.

Self-Collected Specimens Revealed a Higher Vaccine- and Non-Vaccine-Type Human Papillomavirus Prevalences in a Cross-Sectional Study in Akuse

Background

Population-specific epidemiologic data on human Papillomavirus infection, which are limited in most of the SubSaharan African countries, are necessary for effective cervical cancer prevention. This study aimed to generate population-specific data on human Papillomavirus infections, and determine which of these, self-collected and provider-collected specimens, gives a higher estimate of the prevalence of human Papillomaviruses, including vaccine and non-vaccine-type human Papillomavirus.

Methods

In this cross-sectional study, following a questionnaire-based collection of epidemiological data, self-, and provider-collected specimens, obtained from women 15−65 years of age, were analysed for human Papillomavirus types by a nested-multiplex polymerase chain reaction, and for cervical lesions by Pap testing. HPV data were categorised according to risk type and vaccine types for further analysis.

Results

The difference between the overall human Papillomavirus infection prevalences obtained with the self-collected specimens, 43.1% (95% CI of 38.0–51.0%) and that with the provider-collected samples, 23.3% (95% CI of 19.0–31.0%) were significant (p ≤ 0.001). The prevalence of quadrivalent vaccine-type human Papillomaviruses was 12.3% with self-collected specimens, but 6.0% with provider-collected specimens. For the nonavalent vaccine-types, the prevalences were 26.6% and 16.7% respectively. There were multiple infections involving both vaccine-preventable and nonvaccine preventable high-risk human Papillomavirus genotypes.

Conclusion

The Akuse subdistrict can, therefore, be said to have a high burden of human Papillomavirus infections, which included nonvaccine types, as detected with both self-collected and provider-collected specimens. These imply that self-collection is to be given a higher consideration as a means for a population-based high-risk human Papillomavirus infections burdens assessment/screening. Additionally, even with a successful implementation of the HPV vaccination, if introduced in Ghana, there is still the need to continue with the screening of women.

Effectiveness and Cost-Effectiveness of Human Papillomavirus Vaccination Through Age 45 Years in the United States

BACKGROUND

In the United States, the routine age for human papillomavirus (HPV) vaccination is 11 to 12 years, with catch-up vaccination through age 26 years for women and 21 years for men. U.S. vaccination policy on use of the 9-valent HPV vaccine in adult women and men is being reviewed.

OBJECTIVE

To evaluate the added population-level effectiveness and cost-effectiveness of extending the current U.S. HPV vaccination program to women aged 27 to 45 years and men aged 22 to 45 years.

DESIGN

The analysis used HPV-ADVISE (Agent-based Dynamic model for VaccInation and Screening Evaluation), an individual-based transmission dynamic model of HPV infection and associated diseases, calibrated to age-specific U.S. data.

DATA SOURCES

Published data.

TARGET POPULATION

Women aged 27 to 45 years and men aged 22 to 45 years in the United States.

TIME HORIZON

100 years.

PERSPECTIVE

Health care sector.

INTERVENTION

9-valent HPV vaccination.

OUTCOME MEASURES

HPV-associated outcomes prevented and cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

The model predicts that the current U.S. HPV vaccination program will reduce the number of diagnoses of anogenital warts and cervical intraepithelial neoplasia of grade 2 or 3 and cases of cervical cancer and noncervical HPV-associated cancer by 82%, 80%, 59%, and 39%, respectively, over 100 years and is cost saving (vs. no vaccination). In contrast, extending vaccination to women and men aged 45 years is predicted to reduce these outcomes by an additional 0.4, 0.4, 0.2, and 0.2 percentage points, respectively. Vaccinating women and men up to age 30, 40, and 45 years is predicted to cost $830 000, $1 843 000, and $1 471 000, respectively, per quality-adjusted life-year gained (vs. current vaccination).

RESULTS OF SENSITIVITY ANALYSIS

Results were most sensitive to assumptions about natural immunity and progression rates after infection, historical vaccination coverage, and vaccine efficacy.

LIMITATION

Uncertainty about the proportion of HPV-associated disease due to infections after age 26 years and about the level of herd effects from the current HPV vaccination program.

CONCLUSION

The current HPV vaccination program is predicted to be cost saving. Extending vaccination to older ages is predicted to produce small additional health benefits and result in substantially higher incremental cost-effectiveness ratios than the current recommendation.

PRIMARY FUNDING SOURCE

Centers for Disease Control and Prevention.

Engaging Communities in Preventing Human Papillomavirus-Related Cancers: Two Boot Camp Translations, Colorado, 2017-2018

Since 2006, a vaccine to prevent human papillomavirus (HPV) infection has been available; however, uptake is suboptimal. To encourage HPV vaccine uptake, we employed Boot Camp Translation (BCT) to develop locally relevant materials in 2 Colorado communities, Mesa County and the Denver metropolitan area (Denver metro). The Mesa County group focused on 2 populations, parents of vaccine-eligible children and young adults. The group identified posters, social media, and educational materials for pediatric primary care settings as venues to deliver their messages. The Denver metro group focused on parents of children with low health literacy. Four messages explain the vaccine and call the selected audience to action. Delivery tactics for that group are social media venues and print education materials, including refrigerator magnets, to remind parents about follow-up dosing. BCT can be adapted to develop locally relevant messages and intervention strategies to address HPV vaccination. Future studies should evaluate the effectiveness of community-derived messages to increase HPV vaccination rates.

Pitfalls of commercially available HPV tests in HPV68a detection

Background

Human papillomavirus 68 (HPV68) is a probable carcinogenic HPV genotype which is included in almost all HPV screening assays and exists as two genetically variable subtypes (HPV68a and HPV68b). Routine HPV sample testing has shown that the cobas 4800 HPV Test (Roche) provides higher false-negative rates for HPV68 status than PapilloCheck HPV-Screening (Greiner Bio-One). The aim of our study was to evaluate the efficacy of cobas 4800 in HPV68 detection.

Methods

A total of 2,145 cervical/cervicovaginal samples from women aged 17–88 were tested for HPV68 status using the cobas 4800 and PapilloCheck HPV tests. Viral load was assessed by quantitative PCR in all of the HPV68-positive cases. HPV68a/b subtyping was performed with real-time PCR followed by high resolution melting curve analysis, and was subsequently confirmed by Sanger sequencing.

Results

Cobas 4800 detected HPV positivity in only 13/33 HPV68 single-genotype infection cases. Viral load was comparable across both tested subgroups. HRM analysis and Sanger sequencing identified the HPV68a subtype in all of the 20 instances of cobas 4800 false negatives. HPV68a and HPV68b were detected in 3/13 and 10/13 cases identified as other HPV-positive by cobas 4800.

Conclusion

The HPV68a subtype was missed by cobas 4800 in more than 85% of all HPV68a-positive cases. Therefore, commercially available assays may underestimate HPV68 prevalence.

Modeling HPV vaccination scale-up among urban young men who have sex with men in the context of HIV

INTRODUCTION

Young men who have sex with men (YMSM) are at high risk to contract human papillomavirus (HPV). While an effective vaccination exists, its use among YMSM is markedly lower compared to non-MSM and women. This study compares scaling up HPV vaccination in conjunction with other prevention strategies.

METHODS

An agent-based model of urban YMSM (≤26 years of age) reflective of the demography of Philadelphia, PA, simulated for up to ten years of follow-up to examine anal and oral transmission of the HPV genotypes covered in the nonavalent (9v) vaccine: 6, 11, 16, 18, 31, 33, 45, 52, 58. Starting HPV prevalences ranged from a high of 18% (type 6) to a low of 6% (type 31); overall 65% of individuals carried any HPV genotype. Simulated levels of vaccination were ranged from 0% to 13% (present-day level), 25%, 50%, 80% (Healthy People 2020 target), and 100% in conjunction with condom use and HIV seroadaptive practices. The primary outcome was the relative reduction in HPV infection.

RESULTS

Compared to present-day vaccination levels (13%), scaling-up vaccination led to expected declines in 10-year post-simulation HPV prevalence. Anal HPV (any 9v types) declined by 9%, 27%, 46%, and 58% at vaccination levels of 25%, 50%, 80%, and 100%, respectively. Similarly, oral HPV (any 9v types) declined by 11%, 33%, 57%, and 71% across the same levels of vaccine uptake. Comparing the prevention strategies, condoms blocked the greatest number of anal transmissions when vaccination was at or below present-day levels. For oral transmission, vaccination was superior to condom use at all levels of coverage.

CONCLUSIONS

Public health HPV preventions strategies should continue to emphasize the complementary roles of condoms and vaccination, especially for preventing oral infection. Improving vaccination coverage will ultimately have the greatest impact on reducing HPV infection among YMSM.

Estimates of the future burden of cancer attributable to infections in Canada

More than 7000 incident cancers diagnosed in Canada in 2015 were attributable to infections. The future infection-associated cancer burden can be lowered by reducing the prevalence of major cancer-causing infections; hepatitis B virus (HBV), hepatitis C virus (HCV), Helicobacter pylori (H. pylori) and human papillomavirus (HPV). We modeled the future impact of (1) 10%, 25%, and 50% relative reductions in the prevalence of HBV, HCV and H. pylori and (2) different school-based HPV vaccination coverage levels (lower, current, higher) on Canadian cancer incidence by the year 2042. We modeled counterfactual reductions in HBV, HCV and H. pylori prevalence in 2018, assuming a latency period of 15-years, to estimate the impact on cancer incidence starting in 2033. The number of HPV-attributable cancers among vaccinated cohorts was a function of pre-2018 vaccine coverage levels and the 2018 counterfactuals. A 50% counterfactual reduction in the prevalence of HBV, HCV and H. pylori could prevent an estimated 10,585 cancers from 2018 to 2042; a 25% reduction could prevent 5293 cancers and a 10% reduction could prevent 2117 cancers. Assuming continuity of current estimated country-wide HPV vaccine coverage, 3977 anogenital and 1073 head and neck cancers could be prevented from 2018 to 2042, whereas vaccine coverage of 80% in girls and boys could prevent an additional 311 cancers. Almost 16,000 cancers could be prevented in Canada from 2018 to 2042 with a 50% relative reduction in HBV, HCV and H. pylori prevalence and 80% HPV vaccine coverage of girls and boys.

Disparities in Cancer Incidence among Chinese Population versus Migrants to Developed Regions: A Population-Based Comparative Study

BACKGROUND

The incidence of cancer was determined by genetic and environmental factors and varied across the world. The discrepancies in cancer profile among Chinese people living in different regions remained obscure.

METHODS

Chinese people living in urban Shanghai, Hong Kong, Taiwan, Macau, Singapore, and Los Angeles were included in this study. The cancer case data and population data were collected from either the Cancer Incidence in Five Continents Plus database or the regional cancer registry. A rate model was applied to examine the regional differences in cancer risk with Shanghai set as the reference.

RESULTS

From 1983 to 2013, the cancer profiles in most regions were changed. Significant differences in cancer incidence, by sex, period, and age, were detected across regions. The most pronounced disparities were found between Shanghai people and American Chinese in Los Angeles. For cancer site, the most significant differences were detected in prostate, gastrointestinal, gynecologic, oral cavity and pharynx, and brain and central nervous system (CNS) cancers. Specifically, Shanghai was significantly higher in stomach, liver, esophageal, pancreatic, and brain and CNS cancers, while lower in colon, prostate, breast, cervical, and oral cavity and pharynx cancers compared with the other five populations.

CONCLUSIONS

Cancer profile was distinct across Chinese populations, which shared a similar genetic background but lived in different regions. The disparities indicate that cancer development was majorly determined by environmental factors, and suggests that region-tailored cancer prevention strategies were warranted.

IMPACT

The cancer patterns in populations sharing the same genetic background were significantly influenced by different living conditions.

Gynecological Cancers-the Changing Paradigm

Outstanding research in the last few decades led to newer insights into the management of gynecological cancers. In the preventive arena, the efficacy and safety of HPV vaccination are well accepted and is now in addition to bi- and quadrivalent vaccines; there is a nonavalent vaccine against nine oncogenic HPV strains. Recent studies also looked into the dosaging schedules and age of vaccination against HPV to improve the vaccine efficacy and coverage. HPV testing is now approved as a primary screening test for cervical cancer in women aged more than 30 years with better sensitivity than the traditional cytology. Opportunistic salpingectomy for ovarian cancer prevention and neoadjuvant chemotherapy for advanced ovarian cancers are accepted practices. The role of personalized medicine in ovarian cancer and comprehensive genomic analysis of endometrial cancers are also covered in this review.

Human papilloma virus-associated squamous cell carcinoma of the larynx in an 18-year-old woman

BACKGROUND

Human papilloma virus (HPV)-associated malignancies are considered to be sexually transmitted diseases.

METHODS

We report a HPV-positive larynx cancer in an 18-year-old female clarinet player, despite vaccination with the quadrivalent HPV-6-11-16-18-vaccine Gardasil (Merck Sharp & Dohme Corp., West Point, Pennsylvania). The patient showed no evidence of genito-oral infection but showed some evidence for oral-oral HPV transmission through the sharing of saliva-infested clarinet mouthpieces. A right vocal cord lesion of benign appearance was removed via free margin resection.

RESULTS

Histopathology revealed a microinvasive squamous cell carcinoma inside a zone of high-grade dysplasia that was positive for HPV-45. No tumor recurrence was observed during a 4-year follow-up evaluation.

CONCLUSION

Benign lesion appearance and quadrivalent HPV vaccine status do not exclude HPV-associated malignancies. In our patient, the Gardasil vaccine did not provide crossover protection against HPV 45 infection. HPV-associated disease may not necessarily be transmitted via sexual practice patterns alone.

Making HPV vaccination available to girls everywhere

Cervical cancer is currently the fourth leading cause of cancer death among women worldwide, with most cases occurring in low- and middle-income countries. Safe, highly effective vaccines against HPV have been on the market since 2006, yet only 6% of girls worldwide have received this life-saving cancer prevention intervention. International organizations, including PATH, Gavi, and the pharmaceutical companies Merck and GlaxoSmithKline, have provided support to eligible low- and middle-income countries to implement national HPV vaccination programs. Still, glaring disparities in the availability of national HPV vaccination programs and the coverage of the primary target population between the global north and south persist. We illustrate worldwide HPV vaccine implementation and coverage using an online data visualization, which is publicly available and can be used to gain unique insights. We also present three emerging solutions to transform future HPV vaccine delivery in low- and middle-income countries: low-cost generics, single-dose vaccination, and co-administration with other adolescent vaccines. By rapidly expanding access to HPV vaccination to girls everywhere, vaccine-type HPV infections can be virtually eliminated. At high vaccination-coverage levels, more than 80%-or approximately 230 000-of the cervical cancer deaths that occur each year can be averted.

Present challenges in cervical cancer prevention: Answers from cost-effectiveness analyses

Simulation models are commonly used to address important health policy issues that cannot be explored through experimental studies. These models are especially useful to determine a set of strategies that result in a good value for money (cost-effectiveness). Several mathematical models simulating the natural history of HPV and related diseases, especially cervical cancer, have been developed to calculate a relative effectiveness and cost-effectiveness of HPV vaccination and cervical cancer screening interventions. Virtually all cost-effectiveness analyses identify HPV vaccination programmes for preadolescent girls to be cost-effective, even for relatively low vaccination coverage rates. Routine vaccination of preadolescent girls is the primary target population for HPV vaccination as it shows to provide the greatest health impact. Cost-effectiveness analyses assessing other vaccine target groups are less conclusive. Adding additional age-cohorts would accelerate health benefits in some years, although cost-effectiveness becomes less favourable as age at vaccination increases. Including men in HPV vaccination programmes may be a less efficient strategy if done at the expense of female vaccination coverage for reducing the burden of HPV in the population. However, as the HPV vaccine price decreases, the cost-effectiveness of universal vaccination improves, becoming equally as efficient as female-only vaccination. Vaccine price is a decisive factor in the cost-effectiveness analyses. The lower the price, the greater the likelihood that vaccination groups other than the primary target would be considered cost-effective.

Uptake of three doses of HPV vaccine by primary school girls in Eldoret, Kenya; a prospective cohort study in a malaria endemic setting

BACKGROUND

All women are potentially at risk of developing cervical cancer at some point in their life, yet it is avoidable cause of death among women in Sub- Saharan Africa with a world incidence of 530,000 every year. It is the 4th commonest cancer affecting women worldwide with over 260,000 deaths reported in 2012. Low resource settings account for over 75% of the global cervical cancer burden. Uptake of HPV vaccination is limited in the developing world. WHO recommended that 2 doses of HPV vaccine could be given to young girls, based on studies in developed countries. However in Africa high rates of infections like malaria and worms can affect immune responses to vaccines, therefore three doses may still be necessary. The aim of this study was to identify barriers and facilitators associated with uptake of HPV vaccine.

METHODS

A cross-sectional survey was conducted at Eldoret, Kenya involving 3000 girls aged 9 to 14 years from 40 schools. Parents/guardians gave consent through a questionnaire.

RESULTS

Of all 3083 the school girls 93.8% had received childhood vaccines and 63.8% had a second HPV dose, and 39.1% had a third dose. Administration of second dose and HPV knowledge were both strong predictors of completion of the third dose. Distance to the hospital was a statistically significant risk factor for non-completion (P: 0.01).

CONCLUSIONS

Distance to vaccination centers requires a more innovative vaccine-delivery strategy and education of parents/guardians on cervical screening to increase attainment of the HPV vaccination.

High risk human papillomavirus prevalence and genotype distribution among women infected with HIV in Manaus, Amazonas

BACKGROUND

Human immunodeficiency virus (HIV)-positive women have a high prevalence of human papillomavirus (HPV), and are infected with a broader range of HPV types than HIV-negative women. We aimed to determine the prevalence of cervical cytologic abnormalities, high-risk (HR)-HPV prevalence, type distribution according to the severity of cervical lesions and CD4 cell count and identify factors associated with HR-HPV infection among women living with HIV in Manaus, Amazonas.

METHODS

We enrolled 325 women living with HIV that attended an infectious diseases referral hospital. Each woman underwent a gynecological exam, cervical cytology, HR-HPV detection by Polymerase chain Reaction (PCR) using the BD Onclarity™ HPV Assay, colposcopy and biopsy, when necessary. We assessed the associations between potential risk factors and HR-HPV infection.

RESULTS

Overall, 299 (92.0%) women had a PCR result. The prevalence of HR-HPV- infection was 31.1%. The most prevalent HR-HPV types were: 56/59/66 (32.2%), 35/39/68 (28.0%), 52 (21.5%), 16 (19.4%), and 45 (12.9%). Among the women with HR-HPV infection (n = 93), 43.0% had multiple infections. Women with HPV infection showed higher prevalence of cervical abnormalities than that HPV-negative (LSIL: 22.6% vs. 1.5%; HSIL: 10.8% vs. 0.0%). The prevalence of HR-HPV among women with cytological abnormalities was 87.5% for LSIL and 100.0% for HSIL. Women with CD4 < 200 cell/mm³ showed the highest HR-HPV prevalence (59.3%) although this trend was not statistically significant (p-value = 0.62). The mean CD4 cell count decreased with increasing severity of cervical lesions (p-value = 0.001). The multivariable analysis showed that increasing age was associated with a decreased risk of HR-HPV infection with an adjusted prevalence odds ratio of 0.9 (95.0% CI: 0.9-1.0, p-value: 0.03) for each additional year. The only factor statistically significant associated with HR-HPV infection was CD4 cell count.

CONCLUSIONS

HR-HPV and abnormal cytology prevalence are high among women in the Amazonas. The low CD4 cell count was an important determinant of HPV infection and abnormal cytological findings. HPV quadrivalent vaccination used in Brazil might not offer protection for an important fraction of HPV-related disease burden in women living with HIV. This is partly explained by the high presence of non targeted vaccine HR-HPVs, such as the HPV genotype groups 56/59/66, 35/39/68 and individually HPV-52 and HPV-45, some of which contribute to high-grade lesion.

Prediction of cervical cancer incidence in England, UK, up to 2040, under four scenarios: a modelling study

BACKGROUND

In the next 25 years, the epidemiology of cervical cancer in England, UK, will change: human papillomavirus (HPV) screening will be the primary test for cervical cancer. Additionally, the proportion of women screened regularly is decreasing and women who received the HPV vaccine are due to attend screening for the first time. Therefore, we aimed to estimate how vaccination against HPV, changes to the screening test, and falling screening coverage will affect cervical cancer incidence in England up to 2040.

METHODS

We did a data modelling study that combined results from population modelling of incidence trends, observable data from the individual level with use of a generalised linear model, and microsimulation of unobservable disease states. We estimated age-specific absolute risks of cervical cancer in the absence of screening (derived from individual level data). We used an age period cohort model to estimate birth cohort effects. We multiplied the absolute risks by the age cohort effects to provide absolute risks of cervical cancer for unscreened women in different birth cohorts. We obtained relative risks (RRs) of cervical cancer by screening history (never screened, regularly screened, or lapsed attender) using data from a population-based case-control study for unvaccinated women, and using a microsimulation model for vaccinated women. RRs of primary HPV screening were relative to cytology. We used the proportion of women in each 5-year age group (25-29 years to 75-79 years) and 5-year period (2016-20 to 2036-40) who have a combination of screening and vaccination history, and weighted to estimate the population incidence. The primary outcome was the number of cases and rates per 100 000 women under four scenarios: no changes to current screening coverage or vaccine uptake and HPV primary testing from 2019 (status quo), changing the year in which HPV primary testing is introduced, introduction of the nine-valent vaccine, and changes to cervical screening coverage.

FINDINGS

The status quo scenario estimated that the peak age of cancer diagnosis will shift from the ages of 25-29 years in 2011-15 to 55-59 years in 2036-40. Unvaccinated women born between 1975 and 1990 were predicted to have a relatively high risk of cervical cancer throughout their lives. Introduction of primary HPV screening from 2019 could reduce age-standardised rates of cervical cancer at ages 25-64 years by 19%, from 15·1 in 2016 to 12·2 per 100 000 women as soon as 2028. Vaccination against HPV types 16 and 18 (HPV 16/18) could see cervical cancer rates in women aged 25-29 years decrease by 55% (from 20·9 in 2011-15 to 9·5 per 100 000 women by 2036-40), and introduction of nine-valent vaccination from 2019 compared with continuing vaccination against HPV 16/18 will reduce rates by a further 36% (from 9·5 to 6·1 per 100 000 women) by 2036-40. Women born before 1991 will not benefit directly from vaccination; therefore, despite vaccination and primary HPV screening with current screening coverage, European age-standardised rates of cervical cancer at ages 25-79 years will decrease by only 10% (from 12·8 in 2011-15 to 11·5 per 100 000 women in 2036-40). If screening coverage fell to 50%, European age-standardised rates could increase by 27% (from 12·8 to 16·3 per 100 000 by 2036-40).

INTERPRETATION

Going forward, focus should be placed on scenarios that offer less intensive screening for vaccinated women and more on increasing coverage and incorporation of new technologies to enhance current cervical screening among unvaccinated women.

FUNDING

Jo's Cervical Cancer Trust and Cancer Research UK.

The Impact of Human Papillomavirus Catch-Up Vaccination in Australia: Implications for Introduction of Multiple Age Cohort Vaccination and Postvaccination Data Interpretation

We used transmission-dynamic modeling to estimate the added effectiveness of vaccinating multiple cohorts of females (12-26 years) in Australia compared with the theoretical introduction of routine-only (12-13 years) vaccination. Our results suggest that vaccinating multiple cohorts produced markedly faster direct/herd effects, and it added benefits that last for 20-70 years. Furthermore, the number needed to vaccinate to prevent 1 anogential warts (AGW) case or cervical cancer (CC) was similar for routine + catch-up (AGW = 9.9, CC = 678) and routine-only vaccination (AGW = 9.9, CC = 677), thus providing similar levels of efficiency per person vaccinated.

Fraction of high-grade cervical intraepithelial lesions attributable to genotypes targeted by a nonavalent HPV vaccine in Galicia, Spain

Background

Human papillomavirus (HPV) bivalent and quadrivalent vaccines have been widely implemented in worldwide organized immunization programs. A nonavalent HPV vaccine is now available in several countries. The objective was to describe the fraction of squamous non-invasive high-grade cervical intraepithelial lesions attributable to genotypes targeted by bi-quadrivalent vaccines and by nonavalent vaccine according to age and diagnosis in women living in the city of Vigo (Galicia, Spain).

Methods

Cervical scrapings (2009–2014) of women with histological diagnosis of cervical intraepithelial neoplasia grade 2 (CIN2, n = 145) and grade 3-carcinoma in situ (CIN3-CIS, n = 244) were tested with Linear Array HPV Genotyping test (Roche diagnostics, Mannheim, Germany). Hierarchical estimation of the fraction attributable to HPV 16/18 or HPV 31/33/45/52/58 detected alone or in combination was calculated. Absolute additional fraction attributable to genotypes targeted by nonavalent vaccine compared to genotypes targeted by bi-quadrivalent vaccines was calculated as the increment of attributable cases with respect to all studied cases. Age group 1, 2 and 3 included women 18 to 34, 35–44 and ≥45 years old, respectively. EPIDAT 3.1 was used.

Results

Fraction attributable to genotypes targeted by bi-quadrivalent vaccines was 59% CIN2 vs. 69% CIN3-CIS (p < 0.001). It was 63/51/50% of CIN2 and 78/66/45% of CIN3-CIS in age group 1, 2, 3, respectively. Fraction attributable to genotypes targeted by nonavalent vaccine was 86% CIN2 and 86% CIN3-CIS. It was 87/91/75% of CIN2 and 90/86/76% of CIN3-CIS in age group 1, 2, 3, respectively. Fraction attributable to genotypes targeted by these vaccines tended to decrease as age increased (p-trend <0.05). Globally, absolute additional attributable fraction was 16%, 26% and 29% in age group 1, 2 and 3, respectively (p < 0.005).

Conclusions

Absolute additional fraction of CIN2 and CIN3-CIS attributable to genotypes targeted by nonavalent vaccine was observed in women of any age, especially in those over 35 years old.

Multimodal Counseling Interventions: Effect on Human Papilloma Virus Vaccination Acceptance

Human papilloma virus (HPV) vaccine was developed to reduce HPV-attributable cancers, external genital warts (EGW), and recurrent respiratory papillomatosis. Adolescent HPV vaccination series completion rates are less than 40% in the United States of America, but up to 80% in Australia and the United Kingdom. Population-based herd immunity requires 80% or greater vaccination series completion rates. Pro-vaccination counseling facilitates increased vaccination rates. Multimodal counseling interventions may increase HPV vaccination series non-completers’ HPV-attributable disease knowledge and HPV-attributable disease prophylaxis (vaccination) acceptance over a brief 14-sentence counseling intervention. An online, 4-group, randomized controlled trial, with 260 or more participants per group, found that parents were more likely to accept HPV vaccination offers for their children than were childless young adults for themselves (68.2% and 52.9%). A combined audiovisual and patient health education handout (PHEH) intervention raised knowledge of HPV vaccination purpose, p = 0.02, and HPV vaccination acceptance for seven items, p < 0.001 to p = 0.023. The audiovisual intervention increased HPV vaccination acceptance for five items, p < 0.001 to p = 0.006. That HPV causes EGW, and that HPV vaccination prevents HPV-attributable diseases were better conveyed by the combined audiovisual and PHEH than the control 14-sentence counseling intervention alone.

Modelling multi-site transmission of the human papillomavirus and its impact on vaccination effectiveness

OBJECTIVE

Previous HPV models have only included genital transmission, when evidence suggests that transmission between several anatomical sites occurs. We compared model predictions of population-level HPV vaccination effectiveness against genital HPV16 infection in women, using a 1) uni-site (genital site), and a 2) multi-site model (genital and one extragenital site).

METHODS

We developed a uni-site and a multi-site deterministic HPV transmission model, assuming natural immunity was either site-specific or systemic. Both models were calibrated to genital HPV16 prevalence (5%-7.5%), whilst the multi-site model was calibrated to HPV16 prevalence representative of oral (0%-1%) and anal (1%-7.5%) sites. For each model, we identified 2500 parameter sets that fit endemic genital and extragenital prevalences within pre-specified target ranges. In the Base-case analysis, vaccination was girls-only with 40% coverage. Vaccine efficacy was 100% for all sites with lifetime protection. The outcome was the relative reduction in genital HPV16 prevalence among women at post-vaccination equilibrium (RRprev). RRprev was stratified by extragenital prevalence pre-vaccination.

RESULTS

Under assumptions of site-specific immunity, RRprev with the multi-site model was generally greater than with the uni-site model. Differences between the uni-site and multi-site models were greater when transmission from the extragenital site to the genital site was high. Under assumptions of systemic immunity, the multi-site and uni-site models yielded similar RRprev in the scenario without immunity after extragenital infection. In the scenario with systemic immunity after extragenital infection, the multi-site model yielded lower predictions of RRprev than the uni-site model.

CONCLUSIONS

Modelling genital-site only transmission may overestimate vaccination impact if extragenital infections contribute to systemic natural immunity or underestimate vaccination impact if a high proportion of genital infections originate from extragenital infections. Under current understanding of heterosexual HPV transmission and immunity, a substantial bias from using uni-site models in predicting vaccination effectiveness against genital HPV infection is unlikely to occur.

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.

Human papillomavirus 9-valent vaccine for cancer prevention: a systematic review of the available evidence

In 2014, the Food and Drug Administration approved a new human papillomavirus 9-valent vaccine (9vHPV), targeting nine HPV types: HPV types 6, 11, 16, and 18, which are also targeted by the quadrivalent HPV vaccine (qHPV), plus five additional high cancer risk HPV types (HPV types 31, 33, 45, 52, and 58). The aim of the current study was to systematically retrieve, qualitatively and quantitatively pool, as well as critically appraise all available evidence on 9vHPV from randomized controlled trials (RCTs). We conducted a systematic review of the literature on 9vHPV efficacy, immunogenicity and safety, as well as a systematic search of registered, completed, and ongoing RCTs. We retrieved and screened 227 records for eligibility. A total of 10 publications reported on RCTs' results on 9vHPV and were included in the review. Sixteen RCTs on 9vHPV have been registered on RCT registries. There is evidence that 9vHPV generated a response to HPV types 6, 11, 16 and 18 that was non-inferior to qHPV. Vaccine efficacy against five additional HPV type-related diseases was directly assessed on females aged 16-26 years (risk reduction against high-grade cervical, vulvar or vaginal disease = 96·7%, 95% CI 80·9%-99·8%). Bridging efficacy was demonstrated for males and females aged 9-15 years and males aged 16-26 years (the lower bound of the 95% CIs of both the geometric mean titer ratio and difference in seroconversion rates meeting the criteria for non-inferiority for all HPV types). Overall, 9vHPV has been proved to be safe and well tolerated. Other RCTs addressed: 9vHPV co-administration with other vaccines, 9vHPV administration in subjects that previously received qHPV and 9vHPV efficacy in regimens containing fewer than three doses. The inclusion of additional HPV types in 9vHPV offers great potential to expand protection against HPV infection. However, the impact of 9vHPV on reducing the global burden of HPV-related disease will greatly depend on vaccine uptake, coverage, availability, and affordability.

Potential impact of a nonavalent HPV vaccine on HPV related low-and high-grade cervical intraepithelial lesions: A referral hospital-based study in Sicily

While bivalent and quadrivalent HPV vaccines have been used for about 10 years, a nonavalent vaccine against HPV types 6/11/16/18/31/33/45/52 and 58 has been recently approved by FDA and EMA and is now commercially available. The objective of our study was to evaluate the potential impact of the nonavalent vaccine on HPV infection and related low- and high-grade squamous intraepithelial lesions (LSIL, HSIL), compared to the impact of the quadrivalent vaccine, in a female population living in Sicily (Italy). Low estimates of HPV vaccine impact were calculated as prevalence of HPV 6/11/16/18/31/33/45/52 and 58 genotypes, alone or in association, but excluding presence of other HPV types; high estimates were calculated as prevalence of HPV 6/11/16/18/31/33/45/52 and 58 genotypes alone or in association, in the presence of other HPV types. The nonavalent HPV vaccine showed increased impact, compared to the quadrivalent vaccine. Estimates of potential impact varied from 30.9% (low estimate) to 53.3% (high estimate) for LSIL, and from 56.9% to 81,0% for HSIL. The proportion of additional cases potentially prevented by the nonavalent vaccine was 14.4%-23.8% for LSIL, and 19.0%-32.8% for HSIL. The benefit of the nonavalent vaccine compared to the quadrivalent vaccine was more than 80% for both low and high impact estimates for LSIL and more than 50% for both low and high impact estimates for HSIL. The present study confirms that the switch from a first generation HPV vaccines to a nonavalent vaccine would increase the prevention of cervical HSIL in up to 90% of cases.

Mechanistic mathematical models: An underused platform for HPV research

Health economic modeling has become an invaluable methodology for the design and evaluation of clinical and public health interventions against the human papillomavirus (HPV) and associated diseases. At the same time, relatively little attention has been paid to a different yet complementary class of models, namely that of mechanistic mathematical models. The primary focus of mechanistic mathematical models is to better understand the intricate biologic mechanisms and dynamics of disease. Inspired by a long and successful history of mechanistic modeling in other biomedical fields, we highlight several areas of HPV research where mechanistic models have the potential to advance the field. We argue that by building quantitative bridges between biologic mechanism and population level data, mechanistic mathematical models provide a unique platform to enable collaborations between experimentalists who collect data at different physical scales of the HPV infection process. Through such collaborations, mechanistic mathematical models can accelerate and enhance the investigation of HPV and related diseases.

Health economic evaluation of Human Papillomavirus vaccines in women from Venezuela by a lifetime Markov cohort model

Background

Cervical cancer (CC) and genital warts (GW) are a significant public health issue in Venezuela. Our objective was to assess the cost-effectiveness of the two available vaccines, bivalent and quadrivalent, against Human Papillomavirus (HPV) in Venezuelan girls in order to inform decision-makers.

Methods

A previously published Markov cohort model, informed by the best available evidence, was adapted to the Venezuelan context to evaluate the effects of vaccination on health and healthcare costs from the perspective of the healthcare payer in an 11-year-old girls cohort of 264,489. Costs and quality-adjusted life years (QALYs) were discounted at 5%. Eight scenarios were analyzed to depict the cost-effectiveness under alternative vaccine prices, exchange rates and dosing schemes. Deterministic and probabilistic sensitivity analyses were performed.

Results

Compared to screening only, the bivalent and quadrivalent vaccines were cost-saving in all scenarios, avoiding 2,310 and 2,143 deaths, 4,781 and 4,431 CCs up to 18,459 GW for the quadrivalent vaccine and gaining 4,486 and 4,395 discounted QALYs respectively. For both vaccines, the main determinants of variations in the incremental costs-effectiveness ratio after running deterministic and probabilistic sensitivity analyses were transition probabilities, vaccine and cancer-treatment costs and HPV 16 and 18 distribution in CC cases. When comparing vaccines, none of them was consistently more cost-effective than the other. In sensitivity analyses, for these comparisons, the main determinants were GW incidence, the level of cross-protection and, for some scenarios, vaccines costs.

Conclusions

Immunization with the bivalent or quadrivalent HPV vaccines showed to be cost-saving or cost-effective in Venezuela, falling below the threshold of one Gross Domestic Product (GDP) per capita (104,404 VEF) per QALY gained. Deterministic and probabilistic sensitivity analyses confirmed the robustness of these results.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4064-7) contains supplementary material, which is available to authorized users.