Comparative evaluation of the potential impact of rotavirus versus HPV vaccination in GAVI-eligible countries: a preliminary analysis focused on the relative disease burden

Efficacy, Immunogenicity, and Safety of a 9-Valent Human Papillomavirus Vaccine: Subgroup Analysis of Participants From Asian Countries

Background

A 9-valent human papillomavirus-6/11/16/18/31/33/45/52/58 (9vHPV) vaccine extends coverage to 5 next most common oncogenic types (31/33/45/52/58) in cervical cancer versus quadrivalent HPV (qHPV) vaccine. We describe efficacy, immunogenicity, and safety in Asian participants (India, Hong Kong, South Korea, Japan, Taiwan, and Thailand) from 2 international studies: a randomized, double-blinded, qHPV vaccine-controlled efficacy study (young women aged 16–26 years; NCT00543543; Study 001); and an immunogenicity study (girls and boys aged 9–15 years; NCT00943722; Study 002).

Methods

Participants (N = 2519) were vaccinated at day 1 and months 2 and 6. Gynecological samples (Study 001 only) and serum were collected for HPV DNA and antibody assessments, respectively. Injection-site and systemic adverse events (AEs) were monitored. Data were analyzed by country and vaccination group.

Results

9vHPV vaccine prevented HPV-31/33/45/52/58–related persistent infection with 90.4%–100% efficacy across included countries. At month 7, ≥97.9% of participants seroconverted for each HPV type. Injection-site AEs occurred in 77.7%–83.1% and 81.9%–87.5% of qHPV and 9vHPV vaccine recipients in Study 001, respectively, and 62.4%–85.7% of girls/boys in Study 002; most were mild to moderate.

Conclusions

The 9vHPV vaccine is efficacious, immunogenic, and well tolerated in Asian participants. Data support 9vHPV vaccination programs in Asia.

Clinical Trials Registration

NCT00543543; NCT00943722.

Effectiveness of varying number of doses and timing between doses of quadrivalent HPV vaccine against severe cervical lesions

BACKGROUND

Based on immunogenicity studies, a 2 dose HPV vaccination-schedule was recently recommended for girls younger than 15 years. We aimed to investigate the effectiveness of quadrivalent HPV (qHPV) vaccination against CIN2 or worse (CIN2+), by age at vaccination, number of doses, and to test whether optimal timing of 2 doses of qHPV vaccine can confer the same level of protection as the originally recommended three dose-schedule.

METHODS

A population-based cohort of all women aged 13-30 years, living in Denmark or Sweden during 2006-2013, was followed for qHPV vaccination status and first occurrence of CIN2+.

RESULTS

The study cohort comprised 2,253,561 women, of which 33% were vaccinated during follow-up, and 1.7% were diagnosed with CIN2+. Vaccination at ages 13-16 and 17-19 was associated with a reduced risk of CIN2+ after 3 doses (IRR = 0.23, 95% CI 0.11-0.49, and IRR = 0.65, 95% CI 0.41-1.03, respectively), compared to being unvaccinated. After 1 and 2 doses there was a reduced risk, but not statistically significant. Women vaccinated ages 13-16 with 2 doses, where time between first and second dose was 5 months or longer showed no difference in risk compared to 3 doses.

CONCLUSIONS

Women vaccinated with 3 doses of qHPV showed a reduced risk of CIN2+ if they were vaccinated before age 20, with a further reduced risk if vaccinated before age 17. Vaccination with 2 doses, with the second dose 5 months or longer after the first dose, did not yield an increased risk of CIN2+, compared to 3 doses.

Operations research in global health: a scoping review with a focus on the themes of health equity and impact

BACKGROUND

Operations research (OR) is a discipline that uses advanced analytical methods (e.g. simulation, optimisation, decision analysis) to better understand complex systems and aid in decision-making. Herein, we present a scoping review of the use of OR to analyse issues in global health, with an emphasis on health equity and research impact. A systematic search of five databases was designed to identify relevant published literature. A global overview of 1099 studies highlights the geographic distribution of OR and common OR methods used. From this collection of literature, a narrative description of the use of OR across four main application areas of global health - health systems and operations, clinical medicine, public health and health innovation - is also presented. The theme of health equity is then explored in detail through a subset of 44 studies. Health equity is a critical element of global health that cuts across all four application areas, and is an issue particularly amenable to analysis through OR. Finally, we present seven select cases of OR analyses that have been implemented or have influenced decision-making in global health policy or practice. Based on these cases, we identify three key drivers for success in bridging the gap between OR and global health policy, namely international collaboration with stakeholders, use of contextually appropriate data, and varied communication outlets for research findings. Such cases, however, represent a very small proportion of the literature found.

CONCLUSION

Poor availability of representative and quality data, and a lack of collaboration between those who develop OR models and stakeholders in the contexts where OR analyses are intended to serve, were found to be common challenges for effective OR modelling in global health.

Challenges in Cost-Effectiveness Analysis Modelling of HPV Vaccines in Low- and Middle-Income Countries: A Systematic Review and Practice Recommendations

BACKGROUND

Low- and middle-income countries (LMICs) face a number of challenges in implementing cervical cancer prevention programmes that do not apply in high-income countries.

OBJECTIVE

This review assessed how context-specific challenges of implementing cervical cancer prevention strategies in LMICs were accounted for in existing cost-effectiveness analysis (CEA) models of human papillomavirus (HPV) vaccination.

METHODS

The databases of MEDLINE, EMBASE, NHS Economic Evaluation Database, EconLit, Web of Science, and the Center for the Evaluation of Value and Risk in Health (CEA) Registry were searched for studies published from 2006 to 2015. A descriptive, narrative, and interpretative synthesis of data was undertaken.

RESULTS

Of the 33 studies included in the review, the majority acknowledged cost per vaccinated girl (CVG) (26 studies) and vaccine coverage rate (21 studies) as particular challenges for LMICs, while nine studies identified screening coverage rate as a challenge. Most of the studies estimated CVG as a composite of different cost items. However, the basis for the items within this composite cost was unclear. The majority used an assumption rather than an observed rate to represent screening and vaccination coverage rates. CVG, vaccine coverage and screening coverage were shown by some studies through sensitivity analyses to reverse the conclusions regarding cost-effectiveness, thereby significantly affecting policy recommendations.

CONCLUSIONS

While many studies recognized aspects of the particular challenges of HPV vaccination in LMICs, greater efforts need to be made in adapting models to account for these challenges. These include adapting costings of HPV vaccine delivery from other countries, learning from the outcomes of cervical cancer screening programmes in the same geographical region, and taking into account the country's previous experience with other vaccination programmes.

Cervical cancer prevention and treatment research in Africa: a systematic review from a public health perspective

BACKGROUND

Women living in Africa experience the highest burden of cervical cancer. Research and investment to improve vaccination, screening, and treatment efforts are critically needed. We systematically reviewed and characterized recent research within a broader public health framework to organize and assess the range of cervical cancer research in Africa.

METHODS

We searched online databases and the Internet for published articles and cervical cancer reports in African countries. Inclusion criteria included publication between 2004 and 2014, cervical cancer-related content pertinent to one of the four public health categories (primary, secondary, tertiary prevention or quality of life), and conducted in or specifically relevant to countries or regions within the African continent. The study design, geographic region/country, focus of research, and key findings were documented for each eligible article and summarized to illustrate the weight and research coverage in each area. Publications with more than one focus (e.g. secondary and tertiary prevention) were categorized by the primary emphasis of the paper. Research specific to HIV-infected women or focused on feasibility issues was delineated within each of the four public health categories.

RESULTS

A total of 380 research articles/reports were included. The majority (54.6 %) of cervical cancer research in Africa focused on secondary prevention (i.e., screening). The number of publication focusing on primary prevention (23.4 %), particularly HPV vaccination, increased significantly in the past decade. Research regarding the treatment of precancerous lesions and invasive cervical cancer is emerging (17.6 %), but infrastructure and feasibility challenges in many countries have impeded efforts to provide and evaluate treatment. Studies assessing aspects of quality of life among women living with cervical cancer are severely limited (4.1 %). Across all categories, 11.3 % of publications focused on cervical cancer among HIV-infected women, while 17.1 % focused on aspects of feasibility for cervical cancer control efforts.

CONCLUSIONS

Cervical cancer research in African countries has increased steadily over the past decade, but more is needed. Tertiary prevention (i.e. treatment of disease with effective medicine) and quality of life of cervical cancer survivors are two severely under-researched areas. Similarly, there are several countries in Africa with little to no research ever conducted on cervical cancer.

Charting the evolution of approaches employed by the Global Alliance for Vaccines and Immunizations (GAVI) to address inequities in access to immunization: a systematic qualitative review of GAVI policies, strategies and resource allocation mechanisms through an equity lens (1999-2014)

BACKGROUND

GAVI's focus on reducing inequities in access to vaccines, immunization, and GAVI funds, - both between and within countries - has changed over time. This paper charts that evolution.

METHODS

A systematic qualitative review was conducted by searching PubMed, Google Scholar and direct review of available GAVI Board papers, policies, and program guidelines. Documents were included if they described or evaluated GAVI policies, strategies, or programs and discussed equity of access to vaccines, utilization of immunization services, or GAVI funds in countries currently or previously eligible for GAVI support. Findings were grouped thematically, categorized into time periods covering GAVI's phases of operations, and assessed depending on whether the approaches mediated equity of opportunity or equity of outcomes between or within countries.

RESULTS

Serches yielded 2816 documents for assessment. After pre-screening and removal of duplicates, 552 documents underwent detailed evaluation and pertinent information was extracted from 188 unique documents. As a global funding mechanism, GAVI responded rationally to a semi-fixed funding constraint by focusing on between-country equity in allocation of resources. GAVI's predominant focus and documented successes have been in addressing between-country inequities in access to vaccines comparing lower income (GAVI-eligible) countries with higher income (ineligible) countries. GAVI has had mixed results at addressing between-country inequities in utilization of immunization services, and has only more recently put greater emphasis and resources towards addressing within-country inequities in utilization to immunization services. Over time, GAVI has progressively added vaccines to its portfolio. This expansion should have addressed inter-country, inter-regional, inter-generational and gender inequities in disease burden, however, evidence is scant with respect to final outcomes.

CONCLUSION

In its next phase of operations, the Alliance can continue to demonstrate its strength as a highly effective multi-partner enterprise, capable of learning and innovating in a world that has changed much since its inception. By building on its successes, developing more coherent and consistent approaches to address inequities between and within countries and by monitoring progress and outcomes, GAVI is well-positioned to bring the benefits of vaccination to previously unreached and underserved communities towards provision of universal health coverage.

Are current cost-effectiveness thresholds for low- and middle-income countries useful? Examples from the world of vaccines

The World Health Organization's CHOosing Interventions that are Cost Effective (WHO-CHOICE) thresholds for averting a disability-adjusted life-year of one to three times per capita income have been widely cited and used as a measure of cost effectiveness in evaluations of vaccination for low- and middle-income countries (LMICs). These thresholds were based upon criteria set out by the WHO Commission on Macroeconomics and Health, which reflected the potential economic returns of interventions. The CHOICE project sought to evaluate a variety of health interventions at a subregional level and classify them into broad categories to help assist decision makers, but the utility of the thresholds for within-country decision making for individual interventions (given budgetary constraints) has not been adequately explored. To examine whether the 'WHO-CHOICE thresholds' reflect funding decisions, we examined the results of two recent reviews of cost-effectiveness analyses of human papillomavirus and rotavirus vaccination in LMICs, and we assessed whether the results of these studies were reflected in funding decisions for these vaccination programmes. We found that in many cases, programmes that were deemed cost effective were not subsequently implemented in the country. We consider the implications of this finding, the advantages and disadvantages of alternative methods to estimate thresholds, and how cost perspectives and the funders of healthcare may impact on these choices.

Systematic review of the economic value of diarrheal vaccines

Diarrheal disease is a leading cause of child mortality in low-income settings and morbidity across a range of settings. A growing number of studies have addressed the economic value of new and emerging vaccines to reduce this threat. We conducted a systematic review to assess the economic value of diarrheal vaccines targeting a range of pathogens in different settings. The majority of studies focused on the economic value of rotavirus vaccines in different settings, with most of these concluding that vaccination would provide significant economic benefits across a range of vaccine prices. There is also evidence of the economic benefits of cholera vaccines in specific contexts. For other potential diarrheal vaccines data are limited and often hypothetical. Across all target pathogens and contexts, the evidence of economic value focuses the short-term health and economic gains. Additional information is needed on the broader social and long-term economic value of diarrhea vaccines.

Systematic review of studies on rotavirus disease cost-of-illness and productivity loss in Latin America and the Caribbean

BACKGROUND

Rotavirus is the most common cause of severe acute diarrhea among children in both developed and developing countries. Vaccination can reduce the disease burden and its incorporation into health care systems should consider future costs and benefits.

OBJECTIVES

To systematically review studies on costs due to rotavirus infection in Latin America and Caribbean (LAC) region, considering their methods and results.

METHODS

A search of relevant databases including the Cochrane Central Register of Controlled Trials, Embase, MEDLINE via PubMed, the Latin American and Caribbean Health Sciences Literature database (LILACS), and the Brazilian Thesis Databank was performed. Inclusion criteria for studies were: (a) economic evaluation or cost-of-illness studies; (b) conducted in the LAC region; (c) assess economic burden of rotavirus disease or the economic impact of rotavirus vaccination programs. Two authors independently screened the studies for eligibility.

RESULTS

Of 444 studies initially retrieved, 21 met the eligibility criteria and were included (14 cost-effectiveness analyses of vaccination programs and 7 cost-of-illness studies). Direct medical costs were assessed in all 21 studies, but only 10 also investigated indirect and non-medical direct costs. The most commonly observed methods for cost estimation were retrospective database analysis and hospital-based surveillance study. Only one study was a household-based survey.A wide cost range was identified (e.g., inpatient care US$79.91 to US$858.40 and outpatient care US$13.06 to US$64.10), depending on the methods, study perspective, and type of costs included.

CONCLUSION

Rotavirus-associated costs were assessed in 21 studies across the Latin America and Caribbean region. The majority of studies were made alongside economic evaluations of vaccination programs. Methods are broadly different among studies but administrative databases seem to be the most employed source of data.

Human papillomavirus (HPV) vaccine implementation in low and middle-income countries (LMICs): health system experiences and prospects

Prophylactic vaccines for human papillomavirus (HPV) are being introduced in many countries for the prevention of cervical cancer, the second most important cause of cancer-related death in women globally. This is likely to have a significant impact on the future burden of cervical cancer, particularly where screening is non-existent or limited in scale. Previous research on the challenges of vaccinating girls with the HPV vaccine has focused on evidence from developed countries. We conducted a systematic search of the literature in order to describe the barriers and challenges to implementation of HPV vaccine in low- and middle-income countries. We identified literature published post-2006 to September 2012 from five major databases. We validated the findings of the literature review with evidence from qualitative key informant interviews. Three key barriers to HPV vaccine implementation were identified: sociocultural, health systems and political. A linked theme, the sustainability of HPV vaccines programmes in low- and middle-income countries, cuts across these three barriers. Delivering HPV vaccine successfully will require multiple barriers to be addressed. Earlier research in developed countries emphasised sociocultural issues as the most significant barriers for vaccine roll-out. Our evidence suggests that the range of challenges for poorer countries is significantly greater, not least the challenge of reaching girls for three doses in settings where school attendance is low and/or irregular. Financial and political barriers to HPV vaccine roll-out continue to be significant for many poorer countries. Several demonstration and pilot projects have achieved high rates of acceptability and coverage and lessons learned should be documented and shared.

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

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

Costs of delivering human papillomavirus vaccination to schoolgirls in Mwanza Region, Tanzania

BACKGROUND

Cervical cancer is the leading cause of female cancer-related deaths in Tanzania. Vaccination against human papillomavirus (HPV) offers a new opportunity to control this disease. This study aimed to estimate the costs of a school-based HPV vaccination project in three districts in Mwanza Region (NCT ID: NCT01173900), Tanzania and to model incremental scaled-up costs of a regional vaccination program.

METHODS

We first conducted a top-down cost analysis of the vaccination project, comparing observed costs of age-based (girls born in 1998) and class-based (class 6) vaccine delivery in a total of 134 primary schools. Based on the observed project costs, we then modeled incremental costs of a scaled-up vaccination program for Mwanza Region from the perspective of the Tanzanian government, assuming that HPV vaccines would be delivered through the Expanded Programme on Immunization (EPI).

RESULTS

Total economic project costs for delivering 3 doses of HPV vaccine to 4,211 girls were estimated at about US$349,400 (including a vaccine price of US$5 per dose). Costs per fully-immunized girl were lower for class-based delivery than for age-based delivery. Incremental economic scaled-up costs for class-based vaccination of 50,290 girls in Mwanza Region were estimated at US$1.3 million. Economic scaled-up costs per fully-immunized girl were US$26.41, including HPV vaccine at US$5 per dose. Excluding vaccine costs, vaccine could be delivered at an incremental economic cost of US$3.09 per dose and US$9.76 per fully-immunized girl. Financial scaled-up costs, excluding costs of the vaccine and salaries of existing staff were estimated at US$1.73 per dose.

CONCLUSIONS

Project costs of class-based vaccination were found to be below those of age-based vaccination because of more eligible girls being identified and higher vaccine uptake. We estimate that vaccine can be delivered at costs that would make HPV vaccination a very cost-effective intervention. Potentially, integrating HPV vaccine delivery with cost-effective school-based health interventions and a reduction of vaccine price below US$5 per dose would further reduce the costs per fully HPV-immunized girl.

Potential benefits of second-generation human papillomavirus vaccines

Background

Current prophylactic vaccines against human papillomavirus (HPV) target two oncogenic types (16 and 18) that contribute to 70% of cervical cancer cases worldwide. Our objective was to quantify the range of additional benefits conferred by second-generation HPV prophylactic vaccines that are expected to expand protection to five additional oncogenic types (31, 33, 45, 52 and 58).

Methods

A microsimulation model of HPV and cervical cancer calibrated to epidemiological data from two countries (Kenya and Uganda) was used to estimate reductions in lifetime risk of cervical cancer from the second-generation HPV vaccines. We explored the independent and joint impact of uncertain factors (i.e., distribution of HPV types, co-infection with multiple HPV types, and unidentifiable HPV types in cancer) and vaccine properties (i.e., cross-protection against non-targeted HPV types), compared against currently-available vaccines.

Results

Assuming complete uptake of the second-generation vaccine, reductions in lifetime cancer risk were 86.3% in Kenya and 91.8% in Uganda, representing an absolute increase in cervical cancer reduction of 26.1% in Kenya and 17.9% in Uganda, compared with complete uptake of current vaccines. The range of added benefits was 19.6% to 29.1% in Kenya and 14.0% to 19.5% in Uganda, depending on assumptions of cancers attributable to multiple HPV infections and unidentifiable HPV types. These effects were blunted in both countries when assuming vaccine cross-protection with both the current and second-generation vaccines.

Conclusion

Second-generation HPV vaccines that protect against additional oncogenic HPV types have the potential to improve cervical cancer prevention. Co-infection with multiple HPV infections and unidentifiable HPV types can influence vaccine effectiveness, but the magnitude of effect may be moderated by vaccine cross-protective effects. These benefits must be weighed against the cost of the vaccines in future analyses.