Public health impact and cost effectiveness of routine and catch-up vaccination of girls and women with a nine-valent HPV vaccine in Japan: a model-based study

A cost-effectiveness analysis of adult human papillomavirus vaccination strategies in Italy

Vaccination can reduce the public health and economic burden of human papillomavirus (HPV)-associated diseases. In 2023, the Italian national immunization program (NIP) was updated to include HPV vaccination of females ≤26 and males ≤18 years. However, the cost-effectiveness of this update along with proposals to include additional cohorts is unknown. This study evaluates the cost-effectiveness of different HPV vaccination strategies in Italy over a 100-year period, using a published dynamic transmission model with Italy-specific input data. We modeled vaccination of the primary cohort (11 years of age) for 100 years, alone and supplemented with vaccination of additional cohorts for 5-100 years. We found that vaccination of the primary adolescent cohort resulted in substantial, sustained decreases in the incidence and mortality rates of all HPV-related cancers, but smaller, transient decreases in genital warts and recurrent respiratory papillomatosis. Adding supplementary vaccination of additional cohorts for 5-10 years had minor additional public health benefits, while continuing any of the modeled supplementary vaccination strategies for 100 years resulted in more substantial incremental benefits. For example, implementing the 2023-2025 NIP strategy for 100 years averted an additional 21,495 cases of cervical cancer compared to vaccination of the primary cohort alone. All supplementary vaccination strategies that were continued for 10 or 100 years were cost-effective compared to vaccination of the primary cohort alone at a willingness-to-pay threshold of €40,000 per quality-adjusted life year (QALY) gained. The benefits deriving from vaccinating additional cohorts should be considered when developing and updating NIPs.

Cost-effectiveness analysis of 9-valent human papillomavirus vaccine combined with screening for cervical cancer in Japan

OBJECTIVE

In Japan, the current coverage rate of human papillomavirus (HPV) vaccination is only 30%, and the rate of biennial cervical screening is 40%. The Japanese Government has attempted to increase the coverage of HPV vaccination and cervical screening. We analyzed the cost-effectiveness of the 9-valent HPV vaccine and cervical screening in Japan.

METHODS

A yearly cycle Markov model with 15 health states was created to evaluate the cost-effectiveness of the 9-valent HPV vaccination and cervical screening in women aged 12-75 years. We considered four scenarios: 30% coverage of vaccination with 40% coverage of biennial screening (Scenario 1 representing the current Japanese situation), 70% (the highest proportion in 2013 in Japan) and 90% coverage of vaccination with 40% coverage of biennial screening (Scenarios 2 and 3, respectively), and 90% coverage of vaccination with 70% coverage of biennial screening (Scenarios 4). The incremental cost-effectiveness ratio (ICER) was calculated as costs per quality-adjusted life year (QALY) based on the perspective of the healthcare payer and compared with the benchmark for willingness to pay in Japan (41 700 USD per QALY). The cumulative morbidity and mortality in each scenario were analyzed using the Markov model.

RESULTS

Compared with Scenario 1, the ICERs of Scenarios 2, 3, and 4 were 5382, 5321, and 8524 USD/QALY, respectively, which were lower than the benchmark for willingness to pay. As the coverage of HPV vaccination and cervical screening increased, the cumulative morbidity and mortality decreased.

CONCLUSION

Increasing the coverage of the 9-valent HPV vaccination and cervical screening is cost-effective in Japan.

Validating the predicted impact of HPV vaccination on HPV prevalence, cervical lesions, and cervical cancer: A systematic review of population level data and modelling studies

BACKGROUND

We compared model predictions with independently published primary data from population-based studies on the impact of HPV vaccination on HPV prevalence, cervical cancer and its precursors.

METHODS

We searched Cochrane Library, EMBASE, MEDLINE, Web of Science for studies concerning high-income countries published between 2005 to June 2, 2023. Relative risk (RR) for HPV-related outcomes comparing the pre-vaccination and post-vaccination periods were collected from observational and modelling studies. The relationship between vaccination coverage and observed relative reductions was determined using meta-regressions, and we compared model prediction to observations.

FINDINGS

We identified a total of 5649 potential articles, of which one systematic review, 14 observational studies and 32 modelling studies met our inclusion criteria. A clear relation was found between the RR of HPV diseases related outcomes in the pre- versus post-vaccination era and the vaccination coverage, with 23 out of 28 data points and 19 out of 20 data points showing significant reductions in HPV prevalence and CIN2+ prevalence respectively. Around 67 % (n/N = 12/18) of model predictions were more optimistic on HPV prevalence reductions compared to the 95 % CI of the meta-regression derived from observational studies. For CIN2+ lesions, 48 % (n/N = 31/64) of model predictions for CIN2+ outcomes fell within the 95 % CI.

INTERPRETATION

Model predictions and observational data agree that HPV vaccination can have a substantial impact on HPV related outcomes on a population level. Despite large heterogeneity in observational data and modelling studies, it is particularly encouraging that model predictions on the impact of HPV vaccination on CIN2+ model lesions align with observational studies.

FUNDING

Ontario Health (formerly known as Cancer Care Ontario).

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.

Burden of HPV-induced diseases and cost effectiveness of catch-up vaccination in Czech Republic: a model-based study

OBJECTIVES

Human papillomavirus (HPV) infections are highly prevalent sexually transmitted infections, notably associated with various cancers. This study analyses the health and economic impacts of HPV-associated diseases in the Czech Republic and evaluates the cost-effectiveness of a catch-up vaccination program.

METHODS

Utilizing a Markov multistate model, the study assesses the lifetime impacts and costs related to HPV infections. Cohorts of ages 15-21 were simulated to assess the impact of catch-up vaccination outside the 11-year-old age group.

RESULTS

The total quality-adjusted life years (QALYs) for the female and male cohorts (together 119,362 individuals) were higher in the vaccination scenario compared to the non-vaccination scenario. The increase in QALYs was 122,246 and 200,852 respectively, when considering the actual vaccination rates. Across both cohorts, 329 cancer-related deaths were prevented. In the probabilistic sensitivity analysis for the female population, vaccination was the dominant strategy in 99.3% of iterations. In the male population, vaccination was the dominant strategy in 80.3% of iterations. The implementation of catch-up vaccination for the 15-21 age group significantly increased QALY gains and reduced life-years-lost (LYLs). In the female cohort, all analysed rates of catch-up vaccination were the dominant strategy, while in the male cohort, the incremental cost-effectiveness ratios (ICERs) remained consistently below 42,000 CZK/QALY.

CONCLUSIONS

The catch-up vaccination program for 15-21-year-olds is cost-effective and can prevent a significant number of HPV-related cancers in both men and women.

Cost-effectiveness analysis of single-dose or 2-dose of bivalent, quadrivalent, or nonavalent HPV vaccine in a low/middle-income country setting

OBJECTIVE

To compare the health impact and economic benefits among individuals who did not receive the human papillomavirus (HPV) vaccine to those who received a single dose, or 2 doses. The comparison was stratified by 4 types of vaccine in conjunction with primary HPV screening in a low/middle-income country setting.

METHODS

A Markov model was employed to simulate HPV infection and cervical cancer in a cohort of 100,000 12-year-old girls free of HPV. The study scrutinized 9 strategies: 1 dose and 2 doses of 2vHPV (Cervarix®), 2vHPV (Cecolin®), 4vHPV (Gardasil®), 9vHPV vaccine (Gardasil9®), and no vaccination. The primary outcome measure was the quality-adjusted life year (QALY) of each strategy. Incremental cost-effectiveness ratios were estimated over a lifetime horizon, accompanied by sensitivity analyses conducted.

RESULTS

All vaccination programs yielded 41,298-71,057 QALYs gained accompanied by cost savings of 14,914,186-19,821,655 USD compared to no vaccination. Administering 2 doses of 9vHPV vaccine emerged as the most cost-effective strategy, boasting 406 USD/QALY, within a lower willingness to pay threshold. Sensitivity analysis demonstrated an 80% probability of the cost-effectiveness of the 2 doses of 9vHPV vaccine regimen. Furthermore, uncertainty around the costs of vaccination and vaccine efficacy exerted the most substantial influence on the cost-effectiveness findings.

CONCLUSION

Oping for 2 doses of 9vHPV vaccine in conjunction with a primary HPV screening represents the most cost-effective option for implementing a school-based HPV vaccination program targeting 12-year-old girls in Thailand. Such findings provide valuable insights for policymakers in the realm of cervical cancer prevention.

Effectiveness of bivalent HPV vaccination against genital HPV DNA-positivity of a catch-up campaign at age 13-16 years compared to routine vaccination at age 12 years: a biennial repeated cross-sectional study

BACKGROUND

The Netherlands is one of few countries worldwide which has used the bivalent HPV vaccine for girls-only for over a decade. This allows assessment of vaccine effectiveness (VE) against female genital HPV DNA-positivity of this vaccine in an observational post-licencing real-world setting. Additionally, it is unclear whether catch-up vaccination campaigns result in similar VE as routine vaccination. Therefore, type-specific and grouped VE were assessed and compared for women who had been eligible for catch-up vaccination at 13-16 years with those who had been eligible for routine vaccination at 12 years.

METHODS

PASSYON is a Dutch biennial repeated cross-sectional (2011-2021) study among sexual health clinic clients aged 16-24 years old. Women provided self-collected vaginal samples, questionnaires on demographics and sexual behaviour were administered, and women self-reported HPV vaccination status. Samples were analysed using a PCR-based assay (SPF10-LiPA25). Type-specific and grouped VE estimates, adjusted with propensity score stratification, were assessed against genital positivity for 14 HPV types. VE for targeted and non-targeted genotypes were compared between women who had been eligible for the catch-up and those who had been eligible for routine vaccination.

RESULTS

The study included 4488 female participants who had been eligible for HPV vaccination and provided genital swabs (1561 eligible for catch-up, 2927 for routine vaccination). Very high VE against genital HPV-16 and HPV-18 was observed (resp. 93.5% and 89.5%) and significant cross-protection against six other genotypes (HPV-31/33/35/45/52/58), varying from 18.0% (HPV-52) to 79.6% (HPV-45). VE estimates were comparable between women who had been eligible for the catch-up campaign and those eligible for routine vaccination: VE HPV-16/HPV-18: 92.2% (95%CI: 87.9-94.9) vs. 91.8% (95%CI: 86.0-95.2).

CONCLUSIONS

In real-world settings, the VE of bivalent vaccine is high against targeted genotypes, with cross-protection against 6 other genotypes. Catch-up campaigns up to age 16 years can be as effective as routine vaccination at age 12, although it is recommendable to provide HPV vaccination at an age at which most are likely not sexually active yet. This may inform countries considering catch-up campaigns when introducing or extending the use of HPV vaccination within their national immunisation programmes.

Forecasting Disease Burden with a Dynamic Transmission Model of Human Papillomavirus and Recurrent Respiratory Papillomatosis in the United States

Juvenile- and adult-onset recurrent respiratory papillomatosis (JORRP and AORRP) are rare but serious conditions that are caused by oral human papillomavirus (HPV) infections. The proliferation of wart-like growths throughout the respiratory tract can result in medical problems, including death. The current treatment scheme is surgery, though prevention of HPV infection through vaccination is available. A previously developed model for JORRP and AORRP was adapted to the United States using data on disease burden and HPV infection. The model was validated against post-vaccination reductions in disease and used to forecast the future burden of JORRP and AORRP, estimating the impact that HPV vaccination will have on these diseases. Between 2007 (the beginning of HPV vaccination in the US) and 2021, this model estimates that approximately 1393 lives, 22,867 Quality-Adjusted-Life-Years, and over USD 672 million in treatment costs have been saved by HPV vaccination. There is also a substantial reduction in JORRP and AORRP burden, with a 95% reduction in incidence by 2040. Moreover, between 2040 and 2121, the model predicts 3-11 total cases of HPV6/11-related JORRP in the US, and 36-267 total cases of HPV6/11-related AORRP. HPV vaccination in the United States has driven, and will continue to drive, substantial reductions in the public health and economic burden of HPV6/11-related JORRP and AORRP.

Screening for High-Risk Human Papillomavirus Reveals HPV52 and HPV58 among Pediatric and Adult Patient Saliva Samples

Previous research has demonstrated that the human papillomavirus (HPV) can infect a wide range of human tissues, including those within the oral cavity. High-risk oral HPV strains have been associated with the development and progression of oral cancers, including oral squamous cell carcinomas. Although many studies have examined the prevalence of the high-risk strains HPV16 and HPV18, far fewer have assessed the prevalence of other high-risk HPV strains. An approved study protocol was used to identify HPV52 and HPV58 among clinical samples (n = 87) from a saliva biorepository. Quantitative polymerase chain reaction (qPCR) and validated primers for HPV52 and HPV58 were used to facilitate this screening. This screening demonstrated that a total of n = 4/45 or 8.9% of adult saliva samples harbored high-risk HPV52, and n = 2/45 or 4.4% tested positive for high-risk HPV58. In addition, a total of n = 6/42 or 14.3% of the pediatric saliva samples tested positive for high-risk HPV, including n = 5/42 or 11.9% with HPV52 and n = 3/42 or 7.1% for HPV58. These data demonstrate the presence of the high-risk oncogenic HPV52 and HPV58 strains among both adult and pediatric clinical patient samples. More detailed longitudinal research must be conducted to determine whether this prevalence may be increasing or decreasing over time. In addition, these data strongly support public health prevention efforts, such as knowledge and awareness of the nine-valent HPV vaccine covering additional high-risk strains, including HPV52 and HPV58.

Evaluating the cost-effectiveness of HPV vaccination for adolescent girls in Japan: A comparison of 2-valent, 4-valent, and 9-valent HPV vaccines with consideration of cross-protection

OBJECTIVE

In April 2023, the Japanese Health Ministry panel approved the inclusion of the 9-valent human papillomavirus (9vHPV) vaccine in the National Immunization Program, alongside the 2-valent (2vHPV) and 4-valent HPV (4vHPV) vaccines. In response to this, we evaluated the cost-effectiveness of these three vaccines for routine immunization of girls aged 12-16 in Japan, considering the cross-protection of 2vHPV and 4vHPV vaccines.

METHODS

We constructed an age-structured mathematical model for HPV transmission, aiming to quantify the economic and epidemiological effects of various HPV vaccination strategies over a 70-year period in Japan. We determined incremental costs and quality-adjusted life years (QALYs) for each strategy, applying a 3% annual discount. Univariate and probabilistic sensitivity analyses were conducted to assess the uncertainty of our model results, with all evaluations done in 2023.

RESULTS

Our projections indicate that the HPV vaccination program in Japan will significantly reduce the incidence of HPV-related diseases. All HPV vaccination strategies, using the 2vHPV, 4vHPV, and 9vHPV vaccines, were found to be cost-effective compared to no vaccination, with incremental cost-effectiveness ratios of ¥971,447/QALY, ¥1,237,297/QALY, and ¥742,084/QALY, respectively. Direct comparisons between vaccines demonstrated that the 9vHPV vaccination was more cost-effective than the 2vHPV vaccination, whereas 4vHPV vaccination was dominated by 2vHPV vaccination.

CONCLUSIONS

Our study validates the cost-effectiveness of implementing the 9vHPV vaccine as the primary option over the 2vHPV or 4vHPV vaccine for girls in Japan. These findings underscore the need to improve the acceptance rate and coverage of HPV vaccinations in the country.

Cost-effectiveness of nonavalent HPV vaccination in the Netherlands

BACKGROUND

A bivalent human papillomavirus vaccine (2vHPV) is currently used in the Netherlands; a nonavalent vaccine (9vHPV) is also licensed.

RESEARCH DESIGN AND METHODS

We compared the public health and economic benefits of 2vHPV- and 9vHPV-based vaccination strategies in the Netherlands over 100 years using a validated deterministic dynamic transmission metapopulation model.

RESULTS

Compared to 2vHPV, the 9vHPV strategy averted an additional 3,245 cases of and 825 deaths from 9vHPV-strain-attributable cancers, 4,247 cases of and 190 deaths from recurrent respiratory papillomatosis (RRP), and 1,009,637 cases of anogenital warts (AGWs), with an incremental cost-effectiveness ratio (ICER) of €4,975 per quality-adjusted life year (QALY) gained. The ICER increased in a scenario with increased HPV vaccination coverage rates and was relatively robust to one-way deterministic sensitivity analyses, with variation in the disease utility parameter having the most impact. When catch-up vaccination for individuals ≤26 years of age was added to the model, vaccinating with 9vHPV averted additional cancers and AGWs compared to 2vHPV vaccination.

CONCLUSION

Our analyses predict that transitioning from a 2vHPV- to a 9vHPV-based vaccination strategy would be cost-effective in the Netherlands.

Head-to-head immunogenicity comparison of an Escherichia coli-produced 9-valent human papillomavirus vaccine and Gardasil 9 in women aged 18-26 years in China: a randomised blinded clinical trial

BACKGROUND

An Escherichia coli-produced human papillomavirus (HPV) 16 and 18 bivalent vaccine (Cecolin) was prequalified by WHO in 2021. This study aimed to compare the immunogenicity of the E coli-produced HPV 9-valent vaccine Cecolin 9 (against HPV 6, 11, 16, 18, 31, 33, 45, 52, and 58) with Gardasil 9.

METHODS

This was a randomised, single-blind trial conducted in China. Healthy non-pregnant women aged 18-26 years, who were not breastfeeding and with no HPV vaccination history, were enrolled in the Ganyu Centre for Disease Control and Prevention (Lianyungang City, Jiangsu Province, China). Women were stratified by age (18-22 years and 23-26 years) and randomly assigned (1:1) using a permutated block size of eight to receive three doses of Cecolin 9 or Gardasil 9 at day 0, day 45, and month 6. All participants, as well as study personnel without access to the vaccines, were masked. Neutralising antibodies were measured by a triple-colour pseudovirion-based neutralisation assay. The primary outcomes, seroconversion rates and geometric mean concentrations (GMCs) at month 7, were analysed in the per-protocol set for immunogenicity (PPS-I). Non-inferiority was identified for the lower limit of the 95% CI of the GMC ratio (Cecolin 9 vs Gardasil 9) at a margin of 0·5 and a seroconversion rate difference (Cecolin 9-Gardasil 9) at a margin of -5%. This study was registered at ClinicalTrials.gov (NCT04782895) and is completed.

FINDINGS

From March 14 to 18, 2021, a total of 553 potential participants were screened, of which 244 received at least one dose of Cecolin 9 and 243 received at least one dose of Gardasil 9. The seroconversion rates for all HPV types in both groups were 100% in the PPS-I, with the values of the lower limits of 95% CIs for seroconversion rate differences ranging between -1·8% and -1·7%. The GMC ratios of five types were higher than 1·0, with the highest ratio, for HPV 58, at 1·65 (95% CI 1·38-1·97), and those of four types were lower than 1·0, with the lowest ratio, for HPV 11, at 0·79 (0·68-0·93). The incidence of adverse reactions in both groups was similar (43% [104/244] vs 47% [115/243]).

INTERPRETATION

Cecolin 9 induced non-inferior HPV type-specific immune responses compared with Gardasil 9 and is a potential candidate to accelerate the elimination of cervical cancer by allowing for global accessibility to 9-valent HPV vaccinations, especially in low-income and middle-income countries.

FUNDING

National Natural Science Foundation, Fujian Provincial Natural Science Foundation, Xiamen Science and Technology Plan Project, Fundamental Research Funds for the Central Universities, CAMS Innovation Fund for Medical Sciences of China, and Xiamen Innovax.

Public health impact of 2-, 4-, and 9-valent HPV vaccination in females on cervical and noncervical diseases in men and women under different coverage scenarios in China: A simulation study

The high prevalence of human papillomavirus (HPV) infection in China suggests there would be a substantial positive health impact of widespread vaccination against HPV. We adapted a previously described dynamic transmission model of the natural history of HPV infection and related diseases to the Chinese setting to estimate the public health impact in China of 2-valent (with and without cross-protection), 4-valent, and 9-valent HPV vaccination strategies. The model predicted the incidence and mortality associated with HPV-related diseases, including cervical and noncervical cancers, genital warts, and recurrent respiratory papillomatosis (RRP), based on the various vaccination coverage rate (VCR) scenarios, over a 100-year time horizon. The public health impact of the 4 vaccination strategies was estimated in terms of cases and deaths averted compared to a scenario with no vaccination. Under the assumption of various primary and catch-up VCR scenarios, all 4 vaccination strategies reduced the incidence of cervical cancer in females and noncervical cancers in both sexes, and the 4-valent and 9-valent vaccines reduced the incidence of genital warts and RRP in both sexes. The 9-valent vaccination strategy was superior on all outcomes. The number of cervical cancer cases averted over 100 years ranged from ~ 1 million to ~ 5 million while the number of cervical cancer deaths averted was ~ 345,000 to ~ 1.9 million cases, depending on the VCR scenario. The VCR for primary vaccination was the major driver of cases averted.

Accounting for Adverse Events Following Immunization in Economic Evaluation: Systematic Review of Economic Evaluations of Pediatric Vaccines Against Pneumococcus, Rotavirus, Human Papillomavirus, Meningococcus and Measles-Mumps-Rubella-Varicella

OBJECTIVES

Economic evaluations of vaccines should accurately represent all relevant economic and health consequences of vaccination, including losses due to adverse events following immunization (AEFI). We investigated to what extent economic evaluations of pediatric vaccines account for AEFI, which methods are used to do so and whether inclusion of AEFI is associated with study characteristics and the vaccine's safety profile.

METHODS

A systematic literature search (MEDLINE, EMBASE, Cochrane Systematic Reviews and Trials, Database of the Centre for Reviews and Dissemination of the University of York, EconPapers, Paediatric Economic Database Evaluation, Tufts New England Cost-Effectiveness Analysis Registry, Tufts New England Global Health CEA, International Network of Agencies for Health Technology Assessment Database) was performed for economic evaluations published between 2014 and 29 April 2021 (date of search) pertaining to the five groups of pediatric vaccines licensed in Europe and the United States since 1998: the human papillomavirus (HPV) vaccines, the meningococcal vaccines (MCV), the measles-mumps-rubella-varicella (MMRV) combination vaccines, the pneumococcal conjugate vaccines (PCV) and the rotavirus vaccines (RV). Rates of accounting for AEFI were calculated, stratified by study characteristics (e.g., region, publication year, journal impact factor, level of industry involvement) and triangulated with the vaccine's safety profile (Advisory Committee on Immunization Practices [ACIP] recommendations and information on safety-related product label changes). The studies accounting for AEFI were analyzed in terms of the methods used to account for both cost and effect implications of AEFI.

RESULTS

We identified 112 economic evaluations, of which 28 (25%) accounted for AEFI. This proportion was significantly higher for MMRV (80%, four out of five evaluations), MCV (61%, 11 out of 18 evaluations) and RV (60%, nine out of 15 evaluations) compared to HPV (6%, three out of 53 evaluations) and PCV (5%, one out of 21 evaluations). No other study characteristics were associated with a study's likelihood of accounting for AEFI. Vaccines for which AEFI were more frequently accounted for also had a higher frequency of label changes and a higher level of attention to AEFI in ACIP recommendations. Nine studies accounted for both the cost and health implications of AEFI, 18 studies considered only costs and one only health outcomes. While the cost impact was usually estimated based on routine billing data, the adverse health impact of AEFI was usually estimated based on assumptions.

DISCUSSION

Although (mild) AEFI were demonstrated for all five studied vaccines, only a quarter of reviewed studies accounted for these, mostly in an incomplete and inaccurate manner. We provide guidance on which methods to use to better quantify the impact of AEFI on both costs and health outcomes. Policymakers should be aware that the impact of AEFI on cost-effectiveness is likely to be underestimated in the majority of economic evaluations.

Human papillomavirus in cancer: Infection, disease transmission, and progress in vaccines

Human papillomaviruses (HPVs) infect epithelial cells of human beings, and their replication cycle is associated with epithelial differentiation. More than 200 genotypes of HPVs were identified, and each of these HPVs shows distinct specificity for tissues and infection. HPV infection was involved in the development of lesions on the feet, genital warts and hands. The evidence of HPV infection revealed the role of HPVs in neck and head squamous cell carcinoma, esophageal cancer, cervical cancer, head and neck cancer, brain and lung tumours. The independent traditional risk factors, various clinical outcomes, and increased prevalence among certain populations and geographical regions have led increasing interest in HPV infection. The mode of HPVs transmission remains unclear. Moreover, in recent years, vertical transmission of HPVs was reported. This review concludes present knowledge about HPV infection, virulence strains, clinical significance of HPVs, and mode of transmission, and vaccination strategies.

Vaccinating women previously treated for human papillomavirus-related cervical precancerous lesions is highly cost-effective in China

Background

The 2021 Chinese Expert Consensus on the Clinical Application of the Human Papillomavirus (HPV) Vaccine recommended vaccination for women who previously received ablative or excisional treatment for high-grade squamous intraepithelial lesion (HSIL). This study evaluates the cost-effectiveness of HPV vaccination in women previously treated for cervical precancerous lesions.

Methods

We used a Markov model to simulate the disease progression of both low- and high-risk HPV subtypes. We followed a cohort of 100,000 women aged 18-45 years who received treatment for cervical precancerous lesions for a lifetime (80 years). We used the Incremental Cost-Effectiveness Ratios (ICER) with a 5% discount rate to measure the cost-effectiveness of nine vaccination strategies, including a combination of HPV bivalent (HPV-2), quadrivalent (HPV-4) and nonavalent vaccine (HPV-9), each with three vaccination doses (one-, two- and three-dose). We conducted one-way sensitivity analysis and probabilistic sensitivity analysis. We followed the CHEERS 2022 guidelines.

Results

Compared to the status quo, the nine vaccination strategies would result in $3.057-33.124 million incremental cost and 94-1,211 incremental quality-adjusted life-years (QALYs) in 100,000 women previously treated for cervical precancerous lesions. Three vaccination strategies were identified on the cost-effectiveness frontier. In particular, ICER for one-dose HPV-4 vaccination was US$10,025/QALY compared to the status quo (no vaccination); ICER for two-dose HPV-4 vaccination was US$17,641//QALY gained compared to one-dose HPV-4 vaccination; ICER for three-dose HPV-4 vaccination was US$27,785/QALY gained compared with two-dose HPV-4 vaccination. With a willingness-to-pay of three times gross domestic product per capita (US$37655), three-dose HPV-4 vaccination was the most cost-effective vaccination strategy compared with the lower-cost non-dominated strategy on the cost-effectiveness frontier. A probabilistic sensitivity analysis confirmed a 99.1% probability of being cost-effective. If the cost of the HPV-9 is reduced to 50% of the current price, three-dose HPV-9 vaccination would become the most cost-effective strategy.

Discussion

Three-dose HPV-4 vaccination is the most cost-effective vaccination strategy for women treated for precancerous cervical lesions in the Chinese setting.

Assessment of Human Papillomavirus Vaccination in Primary Care Among Swiss University Students

IMPORTANCE

Human papillomavirus vaccination coverage rates lie below desired thresholds in Switzerland. Because general practitioners are the main contact for the relatively rare health issues of many Swiss young adults, primary care offers an important opportunity to provide catch-up human papillomavirus vaccination.

OBJECTIVE

To examine the knowledge, experiences, and attitudes of Swiss university students in the context of receiving human papillomavirus vaccination during primary care visits.

DESIGN, SETTING, AND PARTICIPANTS

This self-administered, cross-sectional, web-based survey study was conducted among students of 3 universities and 1 educational institution for health professions in the Swiss Canton of Zurich. Specific questions about human papillomavirus vaccination experience were directed to respondents who had received at least 1 dose administered by a general practitioner. Responses were collected during 12-week intervals between November 11, 2020, and April 7, 2021, and data were analyzed from August 3 to August 30, 2022.

MAIN OUTCOMES AND MEASURES

The primary outcome was whether human papillomavirus vaccination had been administered on the patient's or the general practitioner's initiative.

RESULTS

The responses of 5524 participants (median [IQR] age, 23 [21-25] years; 3878 women [70.2%]) were analyzed. The survey completion rate was 90.9% (5524 of 6076 students who consented to participate). A total of 2029 respondents (1792 women [46.2%] and 237 men [14.6%]) reported having received at least 1 human papillomavirus vaccination dose, of whom 740 (36.5%) had received at least 1 dose administered by a general practitioner. Among these, 190 respondents (25.7%) reported that vaccine administration had occurred on their request rather than on their general practitioner's initiative. Among all respondents, 4778 (86.5%) wanted to obtain more information about human papillomavirus vaccination at a general practitioner's office, and 2569 (55.3%) rated acute consultations in general practice as inappropriate for addressing human papillomavirus vaccination.

CONCLUSIONS AND RELEVANCE

The findings of this survey study of Swiss university students suggest that primary care shows a high potential for increasing human papillomavirus vaccination coverage rates in Switzerland. However, there was room for improvement in the proactivity of general practitioners, especially with men, and in the attitudes of students toward the appropriateness of acute consultations in general practice for addressing human papillomavirus vaccination.

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%).

Public health impact and cost-effectiveness of switching from bivalent to nonavalent vaccine for human papillomavirus in Norway: incorporating the full health impact of all HPV-related diseases

AIM

The objective of this study was to estimate and compare the cost-effectiveness of switching from a bivalent to a nonavalent human papillomavirus (HPV) vaccination program in Norway, incorporating all nonavalent vaccine-preventable HPV-related diseases and in the context of the latest cervical cancer screening program.

METHODS

A well-established dynamic transmission model of the natural history of HPV infection and disease was adapted to the Norwegian population. We determined the number of cases of HPV-related diseases and subsequent number of deaths, and the economic burden of HPV-related disease under the current standard of care conditions of bivalent and nonavalent vaccinations of girls and boys aged 12 years.

RESULTS

Compared to bivalent vaccination, nonavalent vaccination averted an additional 4,357 cases of HPV-related cancers, 421,925 cases of genital warts, and 543 cases of recurrent respiratory papillomatosis (RRP) over a 100-year time horizon. Nonavalent vaccination also averted an additional 1,044 deaths over the 100-year time horizon when compared with bivalent vaccination. Total costs were higher for the nonavalent strategy (10.5 billion NOK [€1.03 billion] vs. 9.3-9.4 billion NOK [€915-925 million] for bivalent vaccination). A switch to nonavalent vaccination had a higher vaccination cost (4.4 billion NOK [€433 million] vs. 2.7 billion NOK [€266 million] for bivalent vaccination) but resulted in a savings of 627-694 million NOK [€62-68 million] in treatment costs. A switch to nonavalent vaccination demonstrated an incremental cost-effectiveness ratio of 102,500 NOK (€10,086) per QALY versus bivalent vaccination.

CONCLUSIONS

Using a model that incorporated the full range of HPV-related diseases, and the latest cervical cancer screening practices, we found that switching from bivalent to nonavalent vaccination would be considered cost-effective in Norway.

The impact of the COVID-19 pandemic on the national HPV immunization program in Malaysia

In Malaysia, the HPV immunization program has been introduced since 2010 as part of the national immunization plan for female students aged 13 years old. It was a very successful immunization program with good responses from students and parents until the start of COVID-19 pandemic in 2020. The COVID-19 pandemic caused the schools to be closed and resulted about 225000 female students aged 13 years old either missed their vaccination or have incomplete doses of HPV vaccination in 2020 and 2021. This could possibly lead to an increase in cases of cervical cancer and genital warts in the upcoming years. Hence, a wellorganized catch-up HPV vaccination program is vital in ensuring the aim of achieving zero HPV-related infections in the future.

The impact of vaccination on human papillomavirus infection with disassortative geographical mixing: a two-patch modeling study

Human papillomavirus (HPV) infection can spread between regions. What is the impact of disassortative geographical mixing on the dynamics of HPV transmission? Vaccination is effective in preventing HPV infection. How to allocate HPV vaccines between genders within each region and between regions to reduce the total infection? Here we develop a two-patch two-sex model to address these questions. The control reproduction number [Formula: see text] under vaccination is obtained and shown to provide a critical threshold for disease elimination. Both analytical and numerical results reveal that disassortative geographical mixing does not affect [Formula: see text] and only has a minor impact on the disease prevalence in the total population given the vaccine uptake proportional to the population size for each gender in the two patches. When the vaccine uptake is not proportional to the population size, sexual mixing between the two patches can reduce [Formula: see text] and mitigate the consequence of disproportionate vaccine coverage. Using parameters calibrated from the data of a case study, we find that if the two patches have the same or similar sex ratios, allocating vaccines proportionally according to the new recruits in two patches and giving priority to the gender with a smaller recruit rate within each patch will bring the maximum benefit in reducing the total prevalence. We also show that a time-variable vaccination strategy between the two patches can further reduce the disease prevalence. This study provides some quantitative information that may help to develop vaccine distribution strategies in multiple regions with disassortative mixing.

A two-sex model of human papillomavirus infection: Vaccination strategies and a case study

Vaccination is effective in preventing human papillomavirus (HPV) infection. It still remains debatable whether males should be included in a vaccination program and unclear how to allocate the vaccine in genders to achieve the maximum benefits. In this paper, we use a two-sex model to assess HPV vaccination strategies and use the data from Guangxi Province in China as a case study. Both mathematical analysis and numerical simulations show that the basic reproduction number, an important indicator of the transmission potential of the infection, achieves its minimum when the priority of vaccination is given to the gender with a smaller recruit rate. Given a fixed amount of vaccine, splitting the vaccine evenly usually leads to a larger basic reproduction number and a higher prevalence of infection. Vaccination becomes less effective in reducing the infection once the vaccine amount exceeds the smaller recruit rate of the two genders. In the case study, we estimate the basic reproduction number is 1.0333 for HPV 16/18 in people aged 15-55. The minimal bivalent HPV vaccine needed for the disease prevalence to be below 0.05% is 24050 per year, which should be given to females. However, with this vaccination strategy it would require a very long time and a large amount of vaccine to achieve the goal. In contrast with allocating the same vaccine amount every year, we find that a variable vaccination strategy with more vaccine given in the beginning followed by less vaccine in later years can save time and total vaccine amount. The variable vaccination strategy illustrated in this study can help to better distribute the vaccine to reduce the HPV prevalence. Although this work is for HPV infection and the case study is for a province in China, the model, analysis and conclusions may be applicable to other sexually transmitted diseases in other regions or countries.

The impact and cost-effectiveness of 9-valent human papillomavirus vaccine in adolescent females in Hong Kong

Introduction

In Hong Kong (HK), a single-cohort vaccination program for 10–12-year-old girls with the 9-valent human papillomavirus (HPV) vaccine (9vHPV; types 6/11/16/18/31/33/45/52/58) has been launched. This study assessed the public health impact and cost-effectiveness of implementing routine 9vHPV vaccination (12-year-olds) with or without catch-up 9vHPV vaccination (13–18-year-olds) in HK.

Methods

The health impact and costs of implementing routine 9vHPV vaccination with or without catch-up vaccination over a 100-year time horizon were evaluated using a validated HPV-type transmission dynamic model adapted to the HK population; analyses were performed from a healthcare payer perspective. Routine vaccination (12-year-old girls) and catch-up vaccination (13–18 years) assumed vaccine coverage rates of 70% (base case) and 30%, respectively. The model also assumed herd immunity, lifelong vaccine protection, a discount rate of 3%, and a cost per dose of HK dollars (HKD) 858 [United States dollars (USD) 110] and HKD 1390 (USD 179) for the 2-valent HPV (2vHPV) and 9vHPV vaccines, respectively. HPV disease-related incidence and the incremental cost-effectiveness ratio (ICER) per quality-adjusted-life-year (QALY) were estimated. Cost-effectiveness was determined at a ceiling threshold of HK dollars (HKD) 382,046 (USD 49,142) or 1.0 times the gross domestic product per capita of HK.

Results

Compared with routine 9vHPV alone, routine plus catch-up 9vHPV is projected to reduce cervical cancer incidence by 3.4%. Routine plus catch-up 9vHPV will also reduce genital warts incident cases for males/females by 2.6%/5.4%. The incremental cost-effectiveness ratios were HKD 29,911 (USD 3847)/quality-adjusted life-year (QALY) for routine plus catch-up 9vHPV versus routine 9vHPV alone and HKD 25,524 (USD 3283)/QALY for routine 9vHPV alone versus screening only. Sensitivity analyses indicated that routine plus catch-up 9vHPV compared with routine 9vHPV alone remained cost-effective at coverage rates of 30% and 90%.

Conclusions

This analysis predicts that the current HK vaccination strategy can be considered cost-effective and will provide maximum health benefit. These results support addition of the routine 9vHPV vaccine with or without catch-up 9vHPV vaccination to the regional vaccination program in HK.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12962-021-00328-x.

Risk-benefit analysis of 9-valent HPV vaccination for adolescent boys from an individual perspective

Japan recently approved quadrivalent human papillomavirus (HPV) vaccine for males, but 9-valent vaccine is only approved for females. Given the low female vaccination rate due to a concern of adverse events in Japan, quantifying the risk and benefit of the HPV vaccination for male may help the decision making to vaccinate adolescent boys in Japan. Using quality-adjusted life years, the risk-benefit ratio for an adolescent boy to get the 9-valent HPV vaccination was calculated. The male HPV vaccination reduced the QALY gain due to head and neck cancer, anal cancer, penile cancer, genital warts and recurrent respiratory papillomatosis by 401.63, 20.38, 9.40, 28.79 and 69.13/100,000 vaccinated persons, respectively. The total risk of the vaccination was 11.85. The risk-benefit ratio for a 12-year old boy to receive the HPV vaccination series is calculated as 0.022 (the benefit-risk ratio 44.67). In the sensitivity analysis the risk-benefit ratio ranged from 0.0001 to 0.11. for all scenarios. The much larger benefit compared with the risk for the male HPV vaccination was observed from an individual perspective. The result supports the inclusion of sex-neutral HPV vaccination into the national immunization program as well as the decision making for adolescent boys to get the vaccination.