Health and economic benefits of single-dose HPV vaccination in a Gavi-eligible country

Structured Literature Review to Identify Human Papillomavirus's Natural History Parameters for Dynamic Population Models of Vaccine Impacts

Human papillomavirus (HPV) is a common sexually transmitted virus that can cause cervical cancer and other diseases. Dynamic transmission models (DTMs) have been developed to evaluate the health and economic impacts of HPV vaccination. These models typically include many parameters, such as natural history of the disease, transmission, demographic, behavioral, and screening. To ensure the accuracy of DTM projections, it is important to parameterize them with the best available evidence. This study aimed to identify and synthesize data needed to parametrize DTMs on the natural history of HPV infection and related diseases. Parameters describing data of interest were grouped by their anatomical location (genital warts, recurrent respiratory papillomatosis, and cervical, anal, vaginal, vulvar, head and neck, and penile cancers), and natural history (progression, regression, death, cure, recurrence, detection), and were identified through a systematic literature review (SLR) and complementary targeted literature reviews (TLRs). The extracted data were then synthesized by pooling parameter values across publications, and summarized using the range of values across studies reporting each parameter and the median value from the most relevant study. Data were extracted and synthesized from 223 studies identified in the SLR and TLRs. Parameters frequently reported pertained to cervical cancer outcomes, while data for other anatomical locations were less available. The synthesis of the data provides a large volume of parameter values to inform HPV DTMs, such as annual progression rates from cervical intraepithelial neoplasia (CIN) 1 to CIN 2+ (median of highest quality estimate 0.0836), CIN 2 to CIN 3+ (0.0418), carcinoma in situ (CIS) 2 to local cancer+ (0.0396), and regional to distant cancer (0.0474). Our findings suggest that while there is a large body of evidence on cervical cancer, parameter values featured substantial heterogeneity across studies, and further studies are needed to better parametrize the non-cervical components of HPV DTMs.

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.

Cost-Effectiveness of Human Papillomavirus Vaccination in the UK: Two Versus Single-Dose of Nonavalent HPV Vaccination

INTRODUCTION

The UK implemented a single-dose HPV vaccination policy in September 2023, aiming for sustained protection, better vaccine coverage, and reduced healthcare costs. This research assesses the cost-effectiveness of both one-dose and two-dose schedules from a healthcare perspective.

METHODS

Using an age-structured dynamic model, the study analyzed long-term health and economic outcomes of these two different vaccination approaches. It focused on the effects of vaccinating 12- to 13-year-olds with the 9-valent HPV vaccine in either single-dose or two-dose regimens from 2023 to 2093. The analysis, conducted in 2023-2024, explored different immunity durations (10, 30 years, or lifetime) and efficacy levels for the single-dose strategy.

RESULTS

The study indicated that in the UK, vaccinating 12- to 13-year-olds with a two-dose regimen is not considered cost-effective compared to the single-dose option, assumed to be 90% as effective for 10 years. The incremental cost-effectiveness ratios for two doses ranged from £230,903 to £1,082,916 per quality-adjusted life year (QALY), significantly exceeding the UK's £20,000/QALY willingness-to-pay threshold. Over 70 years, a switch from a two-dose to a single-dose vaccination schedule could potentially lead to savings of over £1,073 million in the healthcare system. Furthermore, the single-dose regimen was cost-effective compared to no vaccination, with an incremental cost-effectiveness ratio below £2,040/QALY.

CONCLUSIONS

The study affirms the cost-effectiveness of the UK's single-dose HPV vaccine, in sync with its September 2023 policy shift. The shift not only provides financial benefits but also simplifies vaccine administration, strategically reducing HPV's epidemiological and economic impacts.

Enhanced attenuation of chikungunya vaccines expressing antiviral cytokines

Alphaviruses are vector-borne, medically relevant, positive-stranded RNA viruses that cause disease in animals and humans worldwide. Of this group, chikungunya virus (CHIKV) is the most significant human pathogen, responsible for generating millions of infections leading to severe febrile illness and debilitating chronic joint pain. Currently, there are limited treatments to protect against alphavirus disease; thus, there is a tremendous need to generate safe and effective vaccines. Live-attenuated vaccines (LAVs) are cost-effective and potent immunization strategies capable of generating long-term protection in a single dose. However, LAVs often produce systemic viral replication, which can lead to unwanted post-vaccination side effects and pose a risk of reversion to a pathogenic phenotype and transmission to mosquitoes. Here, we utilized a chimeric infectious clone of CHIKV engineered with the domain C of the E2 gene of Semliki Forest virus (SFV) to express IFNγ and IL-21-two potent antiviral and immunomodulatory cytokines-in order to improve the LAV's attenuation while maintaining immunogenicity. The IFNγ- and IL-21-expressing vaccine candidates were stable during passage and significantly attenuated post-vaccination, as mice experienced reduced footpad swelling with minimal systemic replication and dissemination capacity compared to the parental vaccine. Additionally, these candidates provided complete protection to mice challenged with WT CHIKV. Our dual attenuation strategy represents an innovative way to generate safe and effective alphavirus vaccines that could be applied to other viruses.

HPV vaccination in Africa in the COVID-19 era: a cross-sectional survey of healthcare providers' knowledge, training, and recommendation practices

Introduction

Although the burden of cervical cancer in Africa is highest, HPV vaccination coverage remains alarmingly low in this region. Providers' knowledge and recommendation are key drivers of HPV vaccination uptake. Yet, evidence about providers' knowledge and recommendation practices about the HPV vaccine against a backdrop of emerging vaccine hesitancy fueled by the COVID-19 pandemic is lacking in Africa.

Methods

A cross-sectional study was conducted in 2021-2022 among healthcare providers involved in cervical cancer prevention activities in Africa. They were invited to report prior training, the availability of the HPV vaccine in their practice, whether they recommended the HPV vaccine, and, if not, the reasons for not recommending it. Their knowledge about the HPV vaccine was assessed through self-reporting (perceived knowledge) and with three pre-tested knowledge questions (measured knowledge).

Results

Of the 153 providers from 23 African countries who responded to the survey (mean age: 38.5 years, SD: 10.1), 75 (54.0%) were female and 97 (63.4%) were based In countries with national HPV immunization programs. Overall, 57 (43.8%) reported having received prior training on HPV vaccine education/counseling, and 40 (37.4%) indicated that the HPV vaccine was available at the facility where they work. Most respondents (109, 83.2%) reported recommending the HPV vaccine in their practice. Vaccine unavailability (57.1%), lack of effective communication tools and informational material (28.6%), and need for adequate training (28.6%) were the most commonly reported reasons for not recommending the HPV vaccine. While 63 providers (52.9%) reported that their knowledge about HPV vaccination was adequate for their practice, only 9.9% responded correctly to the 3 knowledge questions.

Conclusion

To increase HPV vaccination coverage and counter misinformation about this vaccine in Africa, adequate training of providers and culturally appropriate educational materials are needed to improve their knowledge of the HPV vaccine and to facilitate effective communication with their patients and the community.

Modeling the Health Impact and Cost-Effectiveness of a Combined Schoolgirl HPV Vaccination and Cervical Cancer Screening Program in Guangdong Province, China

Low human papillomavirus (HPV) vaccine uptake is a key barrier to cervical cancer elimination. We aimed to evaluate the health impact and cost-effectiveness of introducing different HPV vaccines into immunization programs and scaling up the screening program in Guangdong. We used a dynamic compartmental model to estimate the impact of intervention strategies during 2023-2100. We implemented the incremental cost-effectiveness ratio (ICER) in costs per averted disability-adjusted life year (DALY) as an indicator to assess the effectiveness of the intervention. We used an age-standardized incidence of 4 cases per 100,000 women as the threshold for the elimination of cervical cancer. Compared with the status quo, scaling up cervical cancer screening coverage alone would prevent 215,000 (95% CI: 205,000 to 227,000) cervical cancer cases and 49,000 (95% CI: 48,000 to 52,000) deaths during 2023-2100. If the coverage of vaccination reached 90%, domestic two-dose 2vHPV vaccination would be more cost-effective than single-dose and two-dose 9vHPV vaccination. If Guangdong introduced domestic two-dose 2vHPV vaccination at 90% coverage for schoolgirls from 2023 and increased the screening coverage, cervical cancer would be eliminated by 2049 (95% CI 2047 to 2051). Introducing two doses of domestic 2vHPV vaccination for schoolgirls and expanding cervical cancer screening is estimated to be highly cost-effective to accelerate the elimination of cervical cancer in Guangdong.

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.

Optimal allocation strategies for HPV vaccination introduction and expansion in China accommodated to different supply and dose schedule scenarios: A modelling study

BACKGROUND

A key barrier to cervical cancer elimination in China is low human papillomavirus (HPV) vaccine uptake, which is limited by supply constraints, high prices, and restriction to two/three-dose schedule. We explored optimal vaccination strategies for maximizing health and economic benefits accommodated to different supply and dose schedules.

METHODS

We evaluated different HPV vaccine strategies under 4 scenarios with different assumptions about vaccine availability and dose schedules. Each strategy involved different vaccine types, target ages, and modes of delivery. We used a previously validated transmission model to assess the health impact (cervical cancer cases averted), efficiency (number of doses needed to be given to prevent one case of cervical cancer [NND]), and value for money (incremental cost-effectiveness ratio [ICER] and return on investment [ROI]) of different strategies in Chinese females over a 100-year time horizon. All costs are expressed in 2021 dollars. We adopted a societal perspective and discounted quality-adjusted life-years (QALYs), costs and benefits by 3% annually for cost-effectiveness analysis and ROI calculation.

FINDINGS

In a supply-constrained and on-label use scenario, compared with no vaccination, two-dose routine vaccination of 14-year-olds would be the optimal, cost-saving strategy for a future national program (NNDs: 150-220, net cost saving: $15 164 million-$22 034 million, ROIs: 7-14, depending on vaccine type). If the one-dose schedule recommended by WHO is permitted in China, then reallocating the second dose from the routine cohorts to add a catch-up vaccination at 20-year-olds would be the most efficient strategy (NNDs: 73-107), and would be cost-saving compared with routine one-dose vaccination only (net cost saving: $4127 million-$6035 million, ROIs: 19-37). When supply constraints are lifted, scaling up vaccination in older females to 26 years could further expand the health benefits and still be cost-saving compared to maintaining the optimal vaccination strategy in the supply-constrained context.

INTERPRETATION

Our study provides timely evidence for the current and future HPV vaccination strategy planning in China, and may also be of value to other countries with supply and dose restrictions.

FUNDING

Bill & Melinda Gates Foundation; CAMS Innovation Fund for Medical Sciences (CIFMS).

Evaluation of immune response to single dose of quadrivalent HPV vaccine at 10-year post-vaccination

BACKGROUND

The recent World Health Organization recommendation supporting single-dose of HPV vaccine will significantly reduce programmatic cost, mitigate the supply shortage, and simplify logistics, thus allowing more low- and middle-income countries to introduce the vaccine. From a programmatic perspective the durability of protection offered by a single-dose will be a key consideration. The primary objectives of the present study were to determine whether recipients of a single-dose of quadrivalent HPV vaccine had sustained immune response against targeted HPV types (HPV 6,11,16,18) at 10 years post-vaccination and whether this response was superior to the natural antibody titres observed in unvaccinated women.

METHODS

Participants received at age 10-18 years either one, two or three doses of the quadrivalent HPV vaccine. Serology samples were obtained at different timepoints up to 10 years after vaccination from a convenience sample of vaccinated participants and from age-matched unvaccinated women at one timepoint. The evolution of the binding and neutralizing antibody response was presented by dose received. 10-year durability of immune responses induced by a single-dose was compared to that after three doses of the vaccine and in unvaccinated married women.

RESULTS

The dynamics of antibody response among the single-dose recipients observed over 120 months show stabilized levels 18 months after vaccination for all four HPV types. Although the HPV type-specific (binding or neutralizing) antibody titres after a single-dose were significantly inferior to those after three doses of the vaccine (lower bounds of GMT ratios < 0.5), they were all significantly higher than those observed in unvaccinated women following natural infections (GMT ratios: 2.05 to 4.04-fold higher). The results correlate well with the high vaccine efficacy of single-dose against persistent HPV 16/18 infections reported by us earlier at 10-years post-vaccination.

CONCLUSION

Our study demonstrates the high and durable immune response in single-dose recipients of HPV vaccine at 10-years post vaccination.

Gender neutral HPV vaccination programs: Reconsidering policies to expand cancer prevention globally

Human papillomavirus (HPV) infection is responsible for many cancers in both women and men. Cervical cancer, caused by HPV, is the fourth most common cancer among women worldwide, even though it is one of the most preventable cancers. Prevention efforts include HPV vaccination, however these programs remain nascent in many countries. In 2020 the World Health Assembly adopted the Global Strategy for cervical cancer elimination including a goal to fully vaccinate 90% of girls with the HPV vaccine by the age of 15. However, very few countries have reached even 70% coverage. Increased vaccine availability in the future may allow the opportunity to vaccinate more people. This could add to the feasibility of introducing gender-neutral HPV vaccination programs. Adopting a gender-neutral HPV vaccine approach will reduce HPV infections transmitted among the population, combat misinformation, minimize vaccine-related stigma, and promote gender equity. We propose approaching programmatic research through a gender-neutral lens to reduce HPV infections and cancers and promote gender equality. In order to design more effective policies and programs, a better understanding of the perspectives of clients, clinicians, community leaders, and policy-makers is needed. A clear, multi-level understanding of these stakeholders' views will facilitate the development of target policy and programs aimed at addressing common barriers and optimizing uptake. Given the benefit of developing gender-neutral HPV vaccination programs to eliminate cervical cancer and address other HPV associated cancers, we must build knowledge through implementation research around this topic to inform policy-makers and funders for future policy shifts.

Key ethical considerations to guide the adjudication of a single-dose HPV vaccine schedule

There is a high burden of human papillomavirus (HPV) associated cancers in low- and middle-income countries (LMICs). Reducing the recommended dosing schedule from two doses to one makes the vaccine schedule logistically simpler and lowers the cost. This could make the distribution of the current vaccine supply more equitable and lead to the protection of more people. However, the clinical trials studying the efficacy of a single-dose schedule have not yet delivered final results. Against this background, the question is whether a single-dose HPV vaccine recommendation is appropriate now, and if so, what are the ethical considerations of such a recommendation? We developed three ethical recommendations: (1) adopt a holistic view of evidence to justify policy decisions; (2) prioritize the reduction in global disparities in decision-making at all levels; and (3) be transparent in the reporting of how key stakeholder interests have shaped the collection and interpretation of the evidence, and ultimate decisions. The complex discussion regarding the HPV single-dose vaccine schedule highlights the need for in-depth engagement globally to improve our understanding of country-specific contexts, and how those contexts influence decisions regarding the HPV vaccine single-dose recommendation.

Stated preferences for human papillomavirus vaccination for adolescents in selected communities in Ibadan, Southwest Nigeria: A discrete choice experiment

Administration of the human papillomavirus (HPV) vaccine in early adolescence is effective in preventing cervical cancer, a common cancer in sub-Saharan Africa. Nigeria is in the pre-introduction era of the HPV vaccine. Understanding the preferences of the population for the vaccine can help design the HPV immunization program to ensure high uptake of the vaccine. This study explored the preferences for the HPV vaccine among stakeholders in selected communities in Ibadan, Nigeria. A discrete choice experiment survey based on six attributes of the HPV vaccine (which were the number of doses, the efficacy of the vaccine, cost of the vaccine, location of the service point, other benefits of the vaccine apart from prevention of cervical cancer and the odds of a side effect from the vaccine) was carried out in five communities. Data were analyzed using conditional and mixed logit models. Seven hundred community members were recruited, 144 (20.7%) were adolescents and 248 (35.4%) were males. In line with expectations, respondents preferred vaccines with higher efficacy, less severe side effects and lower costs. Preference heterogeneity was identified for adolescents that were less price-sensitive and other community members who were less likely to prefer using schools as the service point. The high socioeconomic class preferred a vaccine that also prevents genital warts. There were variabilities in the preferences for the attributes of the HPV vaccine in the study communities. These variabilities need to be considered in the introduction of the HPV vaccine to ensure high uptake of the vaccine.

Now or later: Health impacts of delaying single-dose HPV vaccine implementation in a high-burden setting

We aimed to quantify the health impact of immediate introduction of a single-dose human papillomavirus (HPV) vaccination program in a high-burden setting, as waiting until forthcoming trials are completed to implement single-dose HPV vaccination may result in health losses, particularly for cohorts who would age-out of vaccination eligibility. Two mathematical models fitted to a high-burden setting projected cervical cancer incidence rates associated with (a) immediate implementation of one-dose HPV vaccination vs (b) waiting 5 years for evidence from randomized trials to determine if one- or two-doses should be implemented. We conducted analyses assuming a single dose was either noninferior or inferior to two doses. The models projected that immediate implementation of a noninferior single-dose vaccine led to a 7.2% to 9.6% increase in cancers averted between 2021 to 2120, compared to waiting 5 years. Health benefits remained greater with immediate implementation despite an inferior single-dose efficacy (80%), but revaccination of one-dose recipients became more important assuming vaccine waning. Under most circumstances, immediate vaccination avoided health losses for those aging out of vaccine eligibility, leading to greater health benefits than waiting for more information in 5 years.

Evidence-based impact projections of single-dose human papillomavirus vaccination in India: a modelling study

BACKGROUND

Despite the high burden of cervical cancer, access to preventive measures remains low in India. A single-dose immunisation schedule could facilitate the scale-up of human papillomavirus (HPV) vaccination, contributing to global elimination of cervical cancer. We projected the effect of single-dose quadrivalent HPV vaccination in India in comparison with no vaccination or to a two-dose schedule.

METHODS

In this modelling study, we adapted an HPV transmission model (EpiMetHeos) to Indian data on sexual behaviour (from the Demographic and Health Survey and the Indian National AIDS Control Organisation), HPV prevalence data (from two local surveys, from the states of Tamil Nadu and West Bengal), and cervical cancer incidence data (from Cancer Incidence in Five Continents for the period 2008-12 [volume XI], and the Indian National Centre for Disease Informatics and Research for the period 2012-16). Using the model, we projected the nationwide and state-specific effect of HPV vaccination on HPV prevalence and cervical cancer incidence, and lifetime risk of cervical cancer, for 100 years after the introduction of vaccination or in the first 50 vaccinated birth cohorts. Projections were derived under a two-dose vaccination scenario assuming life-long protection and under a single-dose vaccination scenario with protection duration assumptions derived from International Agency for Research on Cancer (IARC) India vaccine trial data, in combination with different vaccination coverages and catch-up vaccination age ranges. We used two thresholds to define cervical cancer elimination: an age-standardised incidence rate of less than 4 cases per 100 000 woman-years, and standardised lifetime risk of less than 250 cases per 100 000 women born.

FINDINGS

Assuming vaccination in girls aged 10 years, with 90% coverage, and life-long protection by two-dose or single-dose schedule, HPV vaccination could reduce the prevalence of HPV16 and HPV18 infection by 97% (80% UI 96-99) in 50 years, and the lifetime risk of cervical cancer by 71-78% from 1067 cases per 100 000 women born under a no vaccination scenario to 311 (80% UI 284-339) cases per 100 000 women born in the short term and 233 (219-252) cases per 100 000 women born in the long term in vaccinated cohorts. Under this scenario, we projected that the age-standardised incidence rate threshold for elimination could be met across India (range across Indian states: 1·6 cases [80% UI 1·5-1·7] to 4·0 cases [3·8-4·4] per 100 000 woman-years), while the complementary threshold based on standardised lifetime risk was attainable in 17 (68%) of 25 states, but not nationwide (range across Indian states: 207 cases [80% UI 194-223] to 477 cases [447-514] per 100 000 women born). Under the considered assumptions of waning vaccine protection, single-dose vaccination was projected to have a 21-100% higher per-dose efficiency than two-dose vaccination. Single-dose vaccination with catch-up for girls and women aged 11-20 years was more impactful than two-dose vaccination without catch-up, with reduction of 39-65% versus 38% in lifetime risk of cervical cancer across the ten catch-up birth cohorts and the first ten routine vaccination birth cohorts.

INTERPRETATION

Our evidence-based projections suggest that scaling up cervical cancer prevention through single-dose HPV vaccination could substantially reduce cervical cancer burden in India.

FUNDING

The Bill & Melinda Gates Foundation.

Implementation strategies to increase human papillomavirus vaccination uptake for adolescent girls in sub-Saharan Africa: A scoping review protocol

Introduction

The human papillomavirus (HPV) is sexually transmitted and infects approximately 75% of sexually active people early in their sexual life. Persistent infection with oncogenic HPV types can lead to malignant conditions such as cervical cancer. In 2006, the World Health Organisation approved the use of an efficacious HPV vaccine for girls aged 9 to 14 to prevent HPV-related conditions. Despite the HPV vaccine being available for about 15 years, dose completion remains as low as 20% in sub-Saharan African (SSA) countries implementing the vaccination program compared to 77% in Australia and New Zealand. A fraught of barriers to implementation exist which prevent adequate coverage. Achieving success for HPV vaccination in real-world settings requires strategies to overcome implementation bottlenecks. Therefore, a better understanding and mapping of the implementation strategies used in sub-Saharan Africa to increase HPV vaccination uptake is critical. This review aims to identify implementation strategies to increase HPV vaccination uptake for adolescent girls in sub-Saharan Africa and provide a basis for policy and future research, including systematic reviews to evaluate effective strategies as we accelerate the elimination of cervical cancer.

Materials and methods

This scoping review will consider studies pertaining to implementation strategies to increase HPV vaccination uptake for adolescent girls in sub-Saharan Africa. Studies targeted at different stakeholders to increase adolescent vaccine uptake will be included. Studies using interventions not fitting the definition of implementation strategies as defined by the refined compilation of implementation strategies from the Expert Recommendations for Implementing Change project will be excluded. MEDLINE (via PubMed), Embase, CINAHL (via EBSCO), Scopus and Google Scholar will be searched. Two independent reviewers will screen titles and abstracts for studies that meet the review’s inclusion criteria, and the full text of eligible studies will be reviewed. Data will be extracted from eligible studies using a structured data charting table developed by this team for inclusion by two independent reviewers and presented in a table and graphical form with a narrative summary.

Modeling the health and economic implications of adopting a 1-dose 9-valent human papillomavirus vaccination regimen in a high-income country setting: An analysis in the United Kingdom

Although no human papillomavirus (HPV) vaccine is indicated for single-dose administration, some observational evidence suggests that a 1-dose regimen might reduce HPV infection risk to that achieved with 2 doses. This study estimated the potential health and economic outcomes associated with switching from a 2-dose HPV vaccination program for girls and boys aged 13-14 years to an off-label 9-valent (9vHPV), 1-dose regimen, accounting for the uncertainty of the effectiveness and durability of a single dose. A dynamic HPV transmission infection and disease model was adapted to the United Kingdom and included a probabilistic sensitivity analysis using estimated distributions for duration of protection of 1-dose and degree of protection of 1 relative to 2 doses. One-way sensitivity analyses of key inputs were performed. Outcomes included additional cancer and disease cases and the difference in net monetary benefit (NMB). The 1-dose program was predicted to result in 81,738 additional HPV-related cancer cases in males and females over 100 years compared to the 2-dose program, ranging from 36,673 to 134,347 additional cases (2.5% and 97.5% quantiles, respectively), and had a 7.8% probability of being cost-effective at the £20,000/quality-adjusted life years willingness-to-pay (WTP) threshold. In one-way sensitivity analyses, the number of additional cancer cases was sensitive to the median of the duration of protection distribution and coverage rates. The differences in NMBs were sensitive to the median of the duration of protection distribution, dose price and discount rate, but not coverage variations. Across sensitivity analyses, the probability of 1 dose being cost-effective vs 2 doses was < 50% at the standard WTP threshold. Adoption of a 1-dose 9vHPV vaccination program resulted in more vaccine-preventable HPV-related cancer and disease cases in males and females, introduced substantial uncertainty in health and economic outcomes, and had a low probability of being cost-effective compared to the 2-dose program.

Impact of one and two human papillomavirus (HPV) vaccine doses on community-level HPV prevalence in South African adolescent girls: study protocol and rationale for a pragmatic before-after design

INTRODUCTION

Vaccines against human papillomavirus (HPV) are the key to controlling cervical cancer in low/middle-income countries (LMICs) where incidence is highest, but there have been limited data from these settings on programme impact on HPV prevalence, and none in a population with endemic HIV infection. Furthermore, for many LMICs, the currently recommended two-dose schedule is difficult to deliver at scale, so there is mounting interest in a single-dose schedule.

METHODS AND ANALYSIS

The Human Papillomavirus One and Two-Dose Population Effectiveness Study is a hybrid impact evaluation of the national South African HPV vaccination programme, which has targeted grade 4 girls aged at least 9 years in public schools with two doses of vaccine since 2014, and a single-dose vaccine 'catch-up' programme delivered in one district in 2019. Impacts of both schedules on the prevalence of type-specific HPV infection will be measured using repeat cross-sectional surveys in adolescent girls and young women aged 17-18 years recruited at primary healthcare clinics in the four provinces. A baseline survey in 2019 measured HPV prevalence in the cohort who were ineligible for vaccination because they were already above the target age or grade under either the national programme or the single-dose programme in the selected district. HPV prevalence surveys are repeated in 2021 in the selected district, and in 2023 in all four provinces. We will calculate prevalence ratios to compare the prevalence of HPV types 16 and 18 in the single-dose (2021) and two-dose (2023) cohorts, with the vaccine-ineligible (2019) cohort.

ETHICS AND DISSEMINATION

The project was approved by the University of the Witwatersrand Human Research Ethics Committee (HREC #181005), and the University of New South Wales HREC (#181-005). Findings will be disseminated through peer-reviewed journals, scientific meetings, reports and community forums.

The impact of publicly funded immunization programs on human papillomavirus vaccination in boys and girls: An observational study

Background

Reaching and maintaining high global human papillomavirus (HPV) vaccine uptake has been challenging. The impact of publicly funded HPV immunization programs and the interplay of sociodemographic, psychosocial and policy factors in maximizing vaccination is poorly understood. This observational study examined the impact of introducing publicly funded school-based HPV vaccination programs for boys directly on uptake in boys and indirectly on uptake in girls, while concurrently examining other important sociodemographic and psychosocial factors.

Methods

Data were collected from a national, longitudinal sample of Canadian parents of children aged 9-16 years during August-September 2016 (T1) and June-July 2017 (T2). Participants completed an online questionnaire measuring sociodemographic characteristics, vaccine knowledge and attitudes, health care provider recommendation, and HPV vaccine uptake. Analyses were conducted separately for parents of boys and girls using logistic regression analyses at T1 and T2. Jurisdictions with HPV vaccine funding for boys at both time-points were compared to those with funding at neither time-points and those that introduced funding between time-points.

Findings

The sample included parents of boys (n = 716) and girls (n = 843). In multivariable analyses, jurisdictions with funding for boys at both time-points had higher odds of vaccination (adjusted odds ratio, T1 = 10.18, T2 = 11.42; 95% confidence interval, T1 = 3.08-33.58, T2 = 5.61-23.23) than jurisdictions without funding at both time-points; however, funded jurisdictions did not have higher odds of vaccination compared to jurisdictions that newly introduced funding for boys. Vaccination was associated with consistent determinants in boys and girls including child's age, health care provider recommendation, perceived vaccine harms, and perceived vaccine affordability.

Interpretation

This gender-sensitive analysis highlights the interplay of sociodemographic, psychosocial, and policy factors that can improve HPV vaccination. Publicly funded school-based programs are an impactful strategy to increase vaccine uptake.

Funding

This work was supported by the Canadian Cancer Society Research Institute (#704,036). GKS was supported by the Vanier Canada Graduate Scholarship and Queen Elizabeth II Diamond Jubilee Scholarship programs. The funders of this work had no role in the data collection, analysis, or interpretation, or any aspect pertinent to the study.

Inclusion of Additional Unintended Consequences in Economic Evaluation: A Systematic Review of Immunization and Tuberculosis Cost-Effectiveness Analyses

OBJECTIVE

Our objective was to review economic evaluations of immunization and tuberculosis to determine the extent to which additional unintended consequences were taken into account in the analysis and to describe the methodological approaches used to estimate these, where possible.

METHODS

We sourced the vaccine economic evaluations from a previous systematic review by Nymark et al. (2009-2015) and searched PubMed/MEDLINE and Embase from 2015 to 2019 using the same search strategy. For tuberculosis economic evaluations, we extracted studies from 2009 to 2019 that were published in a previous review by Siapka et al. We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance. Studies were classified according to the categories and subcategories (e.g., herd immunity, non-specific effects, and labor productivity) defined in a framework identifying additional unintended consequences by Nymark and Vassall. Where possible, methods for estimating the additional unintended consequences categories and subcategories were described. We evaluated the reporting quality of included studies according to the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) extraction guideline.

RESULTS

We identified 177 vaccine cost-effectiveness analyses (CEAs) between 2009 and 2019 that met the inclusion criteria. Of these, 98 included unintended consequences. Of the total 98 CEAs, overall health consequence categories were included 73 times; biological categories: herd immunity 43 times; pathogen response: resistance 15 times; and cross-protection 15 times. For health consequences pertaining to the supply-side (health systems) categories, side effects were included five times. On the nonhealth demand side (intrahousehold), labor productivity was included 60 times. We identified 29 tuberculosis CEAs from 2009 to 2019 that met the inclusion criteria. Of these, six articles included labor productivity, four included indirect transmission effects, and one included resistance. Between 2009 and 2019, only 34% of tuberculosis CEAs included additional unintended consequences, compared with 55% of vaccine CEAs.

CONCLUSIONS

The inclusion of additional unintended consequences in economic evaluations of immunization and tuberculosis continues to be limited. Additional unintended consequences of economic benefits, such as those examined in this review and especially those that occur outside the health system, offer valuable information to analysts. Further work on appropriate ways to value these additional unintended consequences is still warranted.

Projections of human papillomavirus (HPV) vaccination impact in Ethiopia, India, Nigeria and Pakistan: a comparative modelling study

Introduction

Cervical cancer is the second most common cancer among women in Ethiopia, India, Nigeria and Pakistan. Our study objective was to assess similarities and differences in vaccine-impact projections through comparative modelling analysis by independently estimating the potential health impact of human papillomavirus (HPV) vaccination.

Methods

Using two widely published models (Harvard and Papillomavirus Rapid Interface for Modelling and Economics (PRIME)) to estimate HPV vaccination impact, we simulated a vaccination scenario of 90% annual coverage among 10 cohorts of 9-year-old girls from 2021 to 2030 in Ethiopia, India, Nigeria and Pakistan. We estimated potential health impact in terms of cervical cancer cases, deaths and disability-adjusted life years averted among vaccinated cohorts from the time of vaccination until 2100. We harmonised the two models by standardising input data to comparatively estimate HPV vaccination impact.

Results

Prior to harmonising model assumptions, the range between PRIME and Harvard models for number of cervical cancer cases averted by HPV vaccination was: 262 000 to 2 70 000 in Ethiopia; 1 640 000 to 1 970 000 in India; 330 000 to 3 36 000 in Nigeria and 111 000 to 1 33 000 in Pakistan. When harmonising model assumptions, alignment on HPV type distribution significantly narrowed differences in vaccine-impact estimates.

Conclusion

Despite model differences, the Harvard and PRIME models yielded similar vaccine-impact estimates. The main differences in estimates are due to variation in interpretation around data on cervical cancer attribution to HPV-16/18. As countries make progress towards WHO targets for cervical cancer elimination, continued explorations of underlying differences in model inputs, assumptions and results when examining cervical cancer prevention policy will be critical.

Single-Dose Human Papillomavirus Vaccination in Low- and Middle-Income Countries-Time for Implementation?

Although cervical cancer is becoming a rare disease in high income regions, it is still a major health issue in low- and middle-income countries (LMICs). Cervical cancer develops after infection with a high-risk human papilloma virus (hrHPV), an infection against which vaccination has been possible since 2006. Large population immunization programs have been organized in many higher income countries, and yet they have not been implemented in most of the lower and middle-income nations. The cost of the vaccine, as well as the need for two doses impedes coverage in the most vulnerable groups. Studies are suggesting the efficacy of single dose vaccination, but so far only observational data are available while large, randomized, double-blind studies are still ongoing. In order to prevent and combat this disease, it is essential to inform the population of vaccination benefits and offer accessible programs in higher as well as low-and middle-income countries. In this commentary, we wish to focus our attention on the case for implementing single dose vaccination in lower- and middle-income nations.

A Framework for Cervical Cancer Elimination in Low-and-Middle-Income Countries: A Scoping Review and Roadmap for Interventions and Research Priorities

The World Health Organization announced an ambitious call for cervical cancer elimination worldwide. With existing prevention and treatment modalities, cervical cancer elimination is now within reach for high-income countries. Despite limited financing and capacity constraints in low-and-middle-income countries (LMICs), prevention and control efforts can be supported through integrated services and new technologies. We conducted this scoping review to outline a roadmap toward cervical cancer elimination in LMICs and highlight evidence-based interventions and research priorities to accelerate cervical cancer elimination. We reviewed and synthesized literature from 2010 to 2020 on primary and secondary cervical cancer prevention strategies. In addition, we conducted expert interviews with gynecologic and infectious disease providers, researchers, and LMIC health officials. Using these data, we developed a logic model to summarize the current state of science and identified evidence gaps and priority research questions for each prevention strategy. The logic model for cervical cancer elimination maps the needs for improved collaboration between policy makers, production and supply, healthcare systems, providers, health workers, and communities. The model articulates responsibilities for stakeholders and visualizes processes to increase access to and coverage of prevention methods. We discuss the challenges of contextual factors and highlight innovation needs. Effective prevention methods include HPV vaccination, screening using visual inspection and HPV testing, and thermocoagulation. However, vaccine coverage remains low in LMICs. New strategies, including single-dose vaccination could enhance impact. Loss to follow-up and treatment delays could be addressed by improved same-day screen-and-treat technologies. We provide a practical framework to guide cervical cancer elimination in LMICs. The scoping review highlights existing and innovative strategies, unmet needs, and collaborations required to achieve elimination across implementation contexts.

Human Papillomavirus Vaccination After COVID-19

The current global novel coronavirus disease 2019 (COVID-19) pandemic threatens to derail the uptake of human papillomavirus (HPV) vaccination in low- and lower-middle income countries with major disruptions to routine immunization and the introduction of new vaccines delayed. This has a major impact on the World Health Organization cervical cancer elimination strategy, where it is dependent on HPV vaccination as well as cervical cancer screening and treatment. We discuss current opportunities and barriers to achieve high uptake of HPV vaccination in low- and lower-middle income countries as well as the impact of COVID-19. Implementation of 4 key recommendations for HPV vaccination in low- and lower-middle income countries is needed: increased global financial investment; improved vaccine supply and accelerated use of a single-dose schedule; education and social marketing; and adoption of universal school-based delivery. With the commitment of the global health community, the adoption of these strategies would underpin the effective elimination of cervical cancer.

Efficacy of the bivalent HPV vaccine against HPV 16/18-associated precancer: long-term follow-up results from the Costa Rica Vaccine Trial

BACKGROUND

Oncogenic human papillomavirus (HPV) infections cause most cases of cervical cancer. Here, we report long-term follow-up results for the Costa Rica Vaccine Trial (publicly funded and initiated before licensure of the HPV vaccines), with the aim of assessing the efficacy of the bivalent HPV vaccine for preventing HPV 16/18-associated cervical intraepithelial neoplasia grade 2 or worse (CIN2+).

METHODS

Women aged 18-25 years were enrolled in a randomised, double-blind, controlled trial in Costa Rica, between June 28, 2004, and Dec 21, 2005, designed to assess the efficacy of a bivalent vaccine for the prevention of infection with HPV 16/18 and associated precancerous lesions at the cervix. Participants were randomly assigned (1:1) to receive an HPV 16/18 AS04-adjuvanted vaccine or control hepatitis A vaccine. Vaccines were administered intramuscularly in three 0·5 mL doses at 0, 1, and 6 months and participants were followed up annually for 4 years. After the blinded phase, women in the HPV vaccine group were invited to enrol in the long-term follow-up study, which extended follow-up for 7 additional years. The control group received HPV vaccine and was replaced with a new unvaccinated control group. Women were followed up every 2 years until year 11. Investigators and patients were aware of treatment allocation for the follow-up phase. At each visit, clinicians collected cervical cells from sexually active women for cytology and HPV testing. Women with abnormal cytology were referred to colposcopy, biopsy, and treatment as needed. Women with negative results at the last screening visit (year 11) exited the long-term follow-up study. The analytical cohort for vaccine efficacy included women who were HPV 16/18 DNA-negative at vaccination. The primary outcome of this analysis was defined as histopathologically confirmed CIN2+ or cervical intraepithelial neoplasia grade 3 or worse associated with HPV 16/18 cervical infection detected at colposcopy referral. We calculated vaccine efficacy by year and cumulatively. This long-term follow-up study is registered with ClinicalTrials.gov, NCT00867464.

FINDINGS

7466 women were enrolled in the Costa Rica Vaccine Trial; 3727 received the HPV vaccine and 3739 received the control vaccine. Between March 30, 2009, and July 5, 2012, 2635 women in the HPV vaccine group and 2836 women in the new unvaccinated control group were enrolled in the long-term follow-up study. 2635 women in the HPV vaccine group and 2677 women in the control group were included in the analysis cohort for years 0-4, and 2073 women from the HPV vaccine group and 2530 women from the new unvaccinated control group were included in the analysis cohort for years 7-11. Median follow-up time for the HPV group was 11·1 years (IQR 9·1-11·7), 4·6 years (4·3-5·3) for the original control group, and 6·2 years (5·5-6·9) for the new unvaccinated control group. At year 11, vaccine efficacy against incident HPV 16/18-associated CIN2+ was 100% (95% CI 89·2-100·0); 34 (1·5%) of 2233 unvaccinated women had a CIN2+ outcome compared with none of 1913 women in the HPV group. Cumulative vaccine efficacy against HPV 16/18-associated CIN2+ over the 11-year period was 97·4% (95% CI 88·0-99·6). Similar protection was observed against HPV 16/18-associated CIN3-specifically at year 11, vaccine efficacy was 100% (95% CI 78·8-100·0) and cumulative vaccine efficacy was 94·9% (73·7-99·4). During the long-term follow-up, no serious adverse events occurred that were deemed related to the HPV vaccine. The most common grade 3 or worse serious adverse events were pregnancy, puerperium, and perinatal conditions (in 255 [10%] of 2530 women in the unvaccinated control group and 201 [10%] of 2073 women in the HPV vaccine group). Four women in the unvaccinated control group and three in the HPV vaccine group died; no deaths were deemed to be related to the HPV vaccine.

INTERPRETATION

The bivalent HPV vaccine has high efficacy against HPV 16/18-associated precancer for more than a decade after initial vaccination, supporting the notion that invasive cervical cancer is preventable.

FUNDING

US National Cancer Institute.

Immunogenicity of Alternative Dosing Schedules for HPV Vaccines among Adolescent Girls and Young Women: A Systematic Review and Meta-Analysis

Alternative dosing schedules for licensed human papilloma virus (HPV) vaccines, particularly single dose and extended intervals between doses (>12 months), are being considered to address vaccine shortages and improve operational flexibility. We searched PUBMED/MEDLINE for publications reporting immunogenicity data following administration of one of the licensed HPV vaccines (2vHPV, 4vHPV, and 9vHPV) to females aged 9–26 years. We conducted non-inferiority analyses comparing alternative to standard schedules using mixed effects meta-regression controlling for baseline HPV status and disaggregated by vaccine, subtype, time point, and age group (9–14 and 15–26 years). Non-inferiority was defined as the lower bound of the 95% confidence interval (CI) for the geometric mean titer (GMT) ratio being greater than 0.5. Our search returned 2464 studies, of which 23 were included in data analyses. When evaluated against standard schedules, although robust immunogenicity was demonstrated across all multi-dose groups, non-inferiority of extended interval dosing was mixed across vaccines, subtypes, and time points. Single dose did not meet the criteria for non-inferiority in any comparisons. Sparse data limited the number of possible comparisons, and further research is warranted.

Evaluation of Durability of a Single Dose of the Bivalent HPV Vaccine: The CVT Trial

BACKGROUND

The authors investigated the durability of vaccine efficacy (VE) against human papillomavirus (HPV)16 or 18 infections and antibody response among nonrandomly assigned women who received a single dose of the bivalent HPV vaccine compared with women who received multiple doses and unvaccinated women.

METHODS

HPV infections were compared between HPV16 or 18-vaccinated women aged 18 to 25 years who received one (N = 112), two (N = 62), or three (N = 1365) doses, and age- and geography-matched unvaccinated women (N = 1783) in the long-term follow-up of the Costa Rica HPV Vaccine Trial. Cervical HPV infections were measured at two study visits, approximately 9 and 11 years after initial HPV vaccination, using National Cancer Institute next-generation sequencing TypeSeq1 assay. VE and 95% confidence intervals (CIs) were estimated. HPV16 or 18 antibody levels were measured in all one- and two-dose women, and a subset of three-dose women, using a virus-like particle-based enzyme-linked immunosorbent assay (n = 448).

RESULTS

Median follow-up for the HPV-vaccinated group was 11.3 years (interquartile range = 10.9-11.7 years) and did not vary by dose group. VE against prevalent HPV16 or 18 infection was 80.2% (95% CI = 70.7% to 87.0%) among three-dose, 83.8% (95% CI = 19.5% to 99.2%) among two-dose, and 82.1% (95% CI = 40.2% to 97.0%) among single-dose women. HPV16 or 18 antibody levels did not qualitatively decline between years four and 11 regardless of the number of doses given, although one-dose titers continue to be statistically significantly lower compared with two- and three-dose titers.

CONCLUSION

More than a decade after HPV vaccination, single-dose VE against HPV16 or 18 infection remained high and HPV16 or 18 antibodies remained stable. A single dose of bivalent HPV vaccine may induce sufficiently durable protection that obviates the need for more doses.

Single-dose nonavalent HPV vaccine: Need of the hour

Human Papilloma Virus (HPV) vaccination of the preadolescent (9-14 years) females is the potential solution to eradicate carcinoma cervix. Nonavalent vaccine provides wider coverage than the quadrivalent vaccine. On long-term follow-up, even after single-dose HPV vaccination, the antibody titer remains good. Herd immunity can also be achieved by HPV vaccination. Hence, mass single-dose nonavalent HPV vaccination for sexually naive preadolescent girls can provide almost 100% protections and a cost-effective approach for the developing countries.

Choosing the optimal HPV vaccine: The health impact and economic value of the nonavalent and bivalent HPV vaccines in 48 Gavi-eligible countries

The human papillomavirus (HPV) vaccines may provide some level of cross-protection against high-risk HPV genotypes not directly targeted by the vaccines. We evaluated the long-term health and economic impacts of routine HPV vaccination using either the nonavalent HPV vaccine or the bivalent HPV vaccine in the context of 48 Gavi-eligible countries. We used a multi-modeling approach to compare the bivalent with or without cross-protection and the nonavalent HPV vaccine. The optimal, that is, most cost-effective, vaccine was the vaccine with an incremental cost-effectiveness ratio below the per-capita gross domestic product (GDP) for each country. By 2100 and assuming 70% HPV vaccination coverage, a bivalent vaccine without cross-protection, a bivalent vaccine with favorable cross-protection and the nonavalent vaccine were projected to avert 14.9, 17.2 and 18.5 million cumulative cases of cervical cancer across all 48 Gavi-eligible countries, respectively. The relative value of the bivalent vaccine compared to the nonavalent vaccine increased assuming a bivalent vaccine conferred high cross-protection. For example, assuming a cost-effectiveness threshold of per-capita GDP, the nonavalent vaccine was optimal in 83% (n = 40) of countries if the bivalent vaccine did not confer cross-protection; however, the proportion of countries decreased to 63% (n = 30) if the bivalent vaccine conferred high cross-protection. For lower cost-effectiveness thresholds, the bivalent vaccine was optimal in a greater proportion of countries, under both cross-protection assumptions. Although the nonavalent vaccine is projected to avert more cases of cervical cancer, the bivalent vaccine with favorable cross-protection can prevent a considerable number of cases and would be considered a high-value vaccine for many Gavi-eligible countries.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Mortality impact of achieving WHO cervical cancer elimination targets: a comparative modelling analysis in 78 low-income and lower-middle-income countries

BACKGROUND

WHO is developing a global strategy towards eliminating cervical cancer as a public health problem, which proposes an elimination threshold of four cases per 100 000 women and includes 2030 triple-intervention coverage targets for scale-up of human papillomavirus (HPV) vaccination to 90%, twice-lifetime cervical screening to 70%, and treatment of pre-invasive lesions and invasive cancer to 90%. We assessed the impact of achieving the 90-70-90 triple-intervention targets on cervical cancer mortality and deaths averted over the next century. We also assessed the potential for the elimination initiative to support target 3.4 of the UN Sustainable Development Goals (SDGs)-a one-third reduction in premature mortality from non-communicable diseases by 2030.

METHODS

The WHO Cervical Cancer Elimination Modelling Consortium (CCEMC) involves three independent, dynamic models of HPV infection, cervical carcinogenesis, screening, and precancer and invasive cancer treatment. Reductions in age-standardised rates of cervical cancer mortality in 78 low-income and lower-middle-income countries (LMICs) were estimated for three core scenarios: girls-only vaccination at age 9 years with catch-up for girls aged 10-14 years; girls-only vaccination plus once-lifetime screening and cancer treatment scale-up; and girls-only vaccination plus twice-lifetime screening and cancer treatment scale-up. Vaccination was assumed to provide 100% lifetime protection against infections with HPV types 16, 18, 31, 33, 45, 52, and 58, and to scale up to 90% coverage in 2020. Cervical screening involved HPV testing at age 35 years, or at ages 35 years and 45 years, with scale-up to 45% coverage by 2023, 70% by 2030, and 90% by 2045, and we assumed that 50% of women with invasive cervical cancer would receive appropriate surgery, radiotherapy, and chemotherapy by 2023, which would increase to 90% by 2030. We summarised results using the median (range) of model predictions.

FINDINGS

In 2020, the estimated cervical cancer mortality rate across all 78 LMICs was 13·2 (range 12·9-14·1) per 100 000 women. Compared to the status quo, by 2030, vaccination alone would have minimal impact on cervical cancer mortality, leading to a 0·1% (0·1-0·5) reduction, but additionally scaling up twice-lifetime screening and cancer treatment would reduce mortality by 34·2% (23·3-37·8), averting 300 000 (300 000-400 000) deaths by 2030 (with similar results for once-lifetime screening). By 2070, scaling up vaccination alone would reduce mortality by 61·7% (61·4-66·1), averting 4·8 million (4·1-4·8) deaths. By 2070, additionally scaling up screening and cancer treatment would reduce mortality by 88·9% (84·0-89·3), averting 13·3 million (13·1-13·6) deaths (with once-lifetime screening), or by 92·3% (88·4-93·0), averting 14·6 million (14·1-14·6) deaths (with twice-lifetime screening). By 2120, vaccination alone would reduce mortality by 89·5% (86·6-89·9), averting 45·8 million (44·7-46·4) deaths. By 2120, additionally scaling up screening and cancer treatment would reduce mortality by 97·9% (95·0-98·0), averting 60·8 million (60·2-61·2) deaths (with once-lifetime screening), or by 98·6% (96·5-98·6), averting 62·6 million (62·1-62·8) deaths (with twice-lifetime screening). With the WHO triple-intervention strategy, over the next 10 years, about half (48% [45-55]) of deaths averted would be in sub-Saharan Africa and almost a third (32% [29-34]) would be in South Asia; over the next 100 years, almost 90% of deaths averted would be in these regions. For premature deaths (age 30-69 years), the WHO triple-intervention strategy would result in rate reductions of 33·9% (24·4-37·9) by 2030, 96·2% (94·3-96·8) by 2070, and 98·6% (96·9-98·8) by 2120.

INTERPRETATION

These findings emphasise the importance of acting immediately on three fronts to scale up vaccination, screening, and treatment for pre-invasive and invasive cervical cancer. In the next 10 years, a one-third reduction in the rate of premature mortality from cervical cancer in LMICs is possible, contributing to the realisation of the 2030 UN SDGs. Over the next century, successful implementation of the WHO elimination strategy would reduce cervical cancer mortality by almost 99% and save more than 62 million women's lives.

FUNDING

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

Potential health impact and cost-effectiveness of bivalent human papillomavirus (HPV) vaccination in Afghanistan

INTRODUCTION

Human papillomavirus (HPV) vaccination has not been introduced in many countries in South-Central Asia, including Afghanistan, despite the sub-region having the highest incidence rate of cervical cancer in Asia. This study estimates the potential health impact and cost-effectiveness of HPV vaccination in Afghanistan to inform national decision-making.

METHOD

An Excel-based static cohort model was used to estimate the lifetime costs and health outcomes of vaccinating a single cohort of 9-year-old girls in the year 2018 with the bivalent HPV vaccine, compared to no vaccination. We also explored a scenario with a catch-up campaign for girls aged 10-14 years. Input parameters were based on local sources, published literature, or assumptions when no data was available. The primary outcome measure was the discounted cost per disability-adjusted life-year (DALY) averted, evaluated from both government and societal perspectives.

RESULTS

Vaccinating a single cohort of 9-year-old girls against HPV in Afghanistan could avert 1718 cervical cancer cases, 125 hospitalizations, and 1612 deaths over the lifetime of the cohort. The incremental cost-effectiveness ratio was US$426 per DALY averted from the government perspective and US$400 per DALY averted from the societal perspective. The estimated annual cost of the HPV vaccination program (US$3,343,311) represents approximately 3.53% of the country's total immunization budget for 2018 or 0.13% of total health expenditures.

CONCLUSION

In Afghanistan, HPV vaccine introduction targeting a single cohort is potentially cost-effective (0.7 times the GDP per capita of $586) from both the government and societal perspective with additional health benefits generated by a catch-up campaign, depending on the government's willingness to pay for the projected health outcomes.

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

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

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General modelling guidelines are insufficient for reporting HPV models.

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

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The framework has seven domains consisting of distinct reporting standards.

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

Costs associated with delivering HPV vaccination in the context of the first year demonstration programme in southern Mozambique

Background

In Mozambique cervical cancer is a public health threat, due to its high incidence and limited access to early diagnosis of precancerous lesions. International organisations are supporting the introduction of human papillomavirus (HPV) vaccines in low- and middle-income countries. Some of these countries recently conducted demonstration programmes, which included evaluation of acceptability, coverage, and practicality of implementation and of integration in existing programmes. Information on costs of delivering the vaccine is needed to overcome the challenges of reaching vaccine potential recipients in rural and remote areas.

Methods

We estimated the financial and economic costs of delivering HPV vaccination to ten-year-old girls at schools for the first vaccination cycle of the demonstration programme in the Manhiça district (southern Mozambique), delivered throughout 2014. We also estimated costs of an alternative scenario with a reduced number of doses and personnel, which was analogous to the second vaccination cycle delivered throughout 2015. Cost estimates followed a micro-costing approach and included interviews with key informants at different administrative levels through the administration of standard questionnaires developed by the World Health Organisation.

Results

Considering only data from the first vaccination cycle (2014), which consisted in the administration of three doses, the average economic cost was US$17.59 per dose and US$52.29 per fully-immunised girl (FIG). Financial cost per dose (US$6.07) and per FIG (US$17.95) were substantially lower. The economic cost was US$15.53 per dose and US$31.14 per FIG when estimating an alternative cost scenario with reduced number of doses and personnel.

Conclusions

The average economic cost per dose was lower than the ones recently reported for low- and middle-income countries. However, our estimation of the financial cost per FIG was higher than the ones observed elsewhere (ranging from US$2.49 in India to US$20.36 in Vietnam) due to the high percentage of out-of-school girls which, reduced vaccine coverage and, therefore, reduced the denominator. Due to budget constraints, if Mozambique is to implement nation-wide HPV vaccination targeted to ten-year-old girls at schools, a reduction in personnel costs should be operated either by restricting the outreach vaccinator team or the number of supervision visits.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-7338-4) contains supplementary material, which is available to authorized users.