Do we fully understand the economic value of vaccines?

Recognizing the Broader Value of Meningococcal Vaccination: A Matter of Evidence, Ability, or Willingness?

OBJECTIVES

It is widely argued that the value of meningococcal vaccination extends beyond the narrow value elements traditionally considered in health technology assessment. Nevertheless, measuring broader value presents challenges, whereas assessment methods and outcomes vary widely. This article investigates the extent to which the broader value of meningococcal vaccination is recognized, considering the available evidence and decision maker's methodological ability and willingness.

METHODS

A targeted literature review informed the classification of broader value elements according to their relevance to meningococcal vaccination and the quality of existing evidence. Focusing on relevant value elements with good evidentiary standards, decision makers' perspectives and methodological ability to consider them were assessed through case studies of health technology assessment of meningococcal B vaccination in England and The Netherlands.

RESULTS

Value elements of high relevance to meningococcal vaccination with good quality evidence include caregivers' health gains, patients' lifetime productivity gains, and disease severity. The willingness and methodological ability to incorporate them into value assessments have been mixed. This is attributable to the scope of the value assessment perspective and the use of evaluation methods that do not fully capture broader value. For other broader value elements, evidence gaps are another potential barrier to value demonstration and recognition.

CONCLUSIONS

The current evidence base confirms that the value of meningococcal vaccination spans beyond healthcare sector effects to health-related externalities, allocative value, and societal economic benefits. To ensure that the most efficient resource allocation outcomes are achieved, countries should consider how to improve their perspective and methodological ability to assess broader value elements accurately.

Does Early Childhood BCG Vaccination Improve Survival to Midlife in a Population With a Low Tuberculosis Prevalence? Quasi-experimental Evidence on Nonspecific Effects From 32 Swedish Birth Cohorts

The Bacillus Calmette-Guérin (BCG) vaccine for tuberculosis (TB) is widely used globally. Many high-income countries discontinued nationwide vaccination policies starting in the 1980s as the TB prevalence decreased. However, there is continued scientific interest in whether the general childhood immunity boost conferred by the BCG vaccination impacts adult health and mortality in low-TB contexts (known as nonspecific effects). While recent studies have found evidence of an association between BCG vaccination and survival to ages 34-45, it is unclear whether these associations are causal or driven by the unobserved characteristics of those who chose to voluntarily vaccinate. We use the abrupt discontinuation of mandatory BCG vaccination in Sweden in 1975 as a natural experiment to estimate the causal nonspecific effect of the BCG vaccine on cohort survival to midlife. Applying two complementary study designs, we find no evidence that survival to age 40 was affected by the discontinuation of childhood BCG vaccination. The results are consistent among both males and females and are robust to several sensitivity tests. Overall, despite prior correlational studies suggesting large nonspecific effects, we do not find any population-level evidence for a nonspecific effect of the BCG vaccine discontinuation on survival to age 40 in Sweden.

Return on Investment (ROI) of Three Vaccination Programmes in Italy: HPV at 12 Years, Herpes Zoster in Adults, and Influenza in the Elderly

The calculation of the return on investment (ROI) allows the estimation of the opportunity cost of a series of interventions and can therefore help to make allocative choices. The objective of this study is to estimate the ROI of three vaccinations (HPV for adolescents, HZ for adults, and influenza for the elderly) in the Italian context, considering the impact of increasing vaccination coverage based on target objectives of the National Immunization Plan (PNPV) 2017-2019 and accounting for different eligibility criteria of each vaccination. Three separate static cohort models were constructed, including the eligible population for these vaccinations on the basis of the PNPV 2017-2019 and following this population until death (lifetime horizon) or until vaccination waning. Each model compares the level of investment at current vaccine coverage rates (current VCRs scenario) with that of optimal NIP target VCRs with a non-vaccination scenario. The ROI for HPV vaccination was the highest among the programs compared and was always above 1 (range: 1.4-3.58), while lower values were estimated for influenza vaccination in the elderly (range 0.48-0.53) and for vaccination against HZ (range: 0.09-0.27). Our analysis showed that a significant proportion of savings generated by vaccination programs occurred outside the NHS perspective and might often not be estimated with other forms of economic evaluation.

A Case Series and Literature Review of Telogen Effluvium and Alopecia Universalis after the Administration of a Heterologous COVID-19 Vaccine Scheme

COVID-19 vaccines have positively changed the course of the pandemic. They entered the market after only one year of the initial trials, which that yielded positive results in terms of safety and efficacy. However, after inoculating billions of people in the most extensive vaccination campaign worldwide, mild but common and some rare but potentially fatal adverse events have been reported. Among several self-reported adverse events, hair loss and alopecia have been linked to COVID-19 mRNA or viral vector vaccines. We tracked and followed a series of five cases with post-vaccine telogen effluvium and alopecia development in Ecuador. Here, we reported the clinical presentation of two women and three men with the diagnosis of post-vaccine hair loss. All patients received a heterologous vaccination scheme (mRNA and attenuated virus vaccine) with an additional viral vector booster associated with the apparition of telogen effluvium and alopecia universalis between 3 and 17 days after the vaccine was administered.

A Comparative Analysis of a Self-Reported Adverse Events Analysis after Receiving One of the Available SARS-CoV-2 Vaccine Schemes in Ecuador

The COVID-19 pandemic has put a lot of pressure on health systems worldwide. Mass vaccination against SARS-CoV-2 has reduced morbidity and mortality worldwide. Despite their safety profiles, vaccines, as with any other medical product, can cause adverse events. Yet, in countries with poor epidemiological surveillance and monitoring systems, reporting vaccine-related adverse events is a challenge. The objective of this study was to describe self-reported vaccine adverse events after receiving one of the available COVID-19 vaccine schemes in Ecuador. A cross-sectional analysis based on an online, self-reported, 32-item questionnaire was conducted in Ecuador from 1 April to 15 July 2021. Participants were invited by social media, radio, and TV to voluntarily participate in our study. A total of 6654 participants were included in this study. Furthermore, 38.2% of the participants reported having at least one comorbidity. Patients received AstraZeneca, Pfizer, and Sinovac vaccines, and these were distributed 38.4%, 31.1%, and 30.5%, respectively. Overall, pain or swelling at the injection site 17.2% (n = 4500) and headache 13.3% (n = 3502) were the most reported adverse events. Women addressed events supposedly attributable to vaccination or immunization [ESAVIs] (66.7%), more often than men (33.2%). After receiving the first dose of any available COVID-19 vaccine, a total of 19,501 self-reported ESAVIs were informed (87.0% were mild, 11.5% moderate, and 1.5% severe). In terms of the vaccine type and brand, the most reactogenic vaccine was AstraZeneca with 57.8%, followed by Pfizer (24.9%) and Sinovac (17.3%). After the second dose, 6776 self-reported ESAVIs were reported (87.1% mild, 10.9% moderate, and 2.1% severe). AstraZeneca vaccine users reported a higher proportion of ESAVIs (72.2%) in comparison to Pfizer/BioNTech (15.9%) and Sinovac Vaccine (11.9%). Swelling at the injection site, headache, muscle pain, and fatigue were the most common ESAVIs for the first as well as second doses. In conclusion, most ESAVIs were mild. AstraZeneca users were more likely to report adverse events. Participants without a history of COVID-19 infection, as well as those who received the first dose, were more prone to report ESAVIs.

Capturing the value of vaccination within health technology assessment and health economics: Literature review and novel conceptual framework

BACKGROUND

Vaccination provides significant health gains to individuals and society and can potentially improve health equity, healthcare systems and national economies. Policy decisions, however, are rarely informed by comprehensive economic evaluations (EE) including vaccination's wide-ranging value. The objective of this analysis was to focus on health technology assessment systems to identify relevant value concepts in order to improve current EE of non-pandemic vaccines.

METHODS

Following a literature review, a novel Value of Vaccination (VoV) framework was developed with experts in vaccine EE from developed countries with established health technology assessment systems.

RESULTS

Forty-four studies presenting value frameworks or concepts applicable to vaccination were included. Eighteen unique value concepts relevant to EE were identified and defined. These were categorised within the VoV framework using three dimensions, moving from a narrow payer perspective to a more expansive and societal perspective. The dimensions were: (I) conventional payer perspective concepts (e.g., health gains in vaccinees, direct medical costs); (II) conventional societal perspective concepts (e.g., indirect health/economic gains to caregivers/households, productivity in vaccinees); and (III) novel societal concepts (e.g., financial risk protection, peace of mind, societal health gains, healthcare systems security, political stability, social equity and macroeconomic gains). While good quality evidence and methods are available to support concepts in Dimensions I and II, further work is needed to generate the required evidence for vaccination impact on Dimension III concepts.

CONCLUSIONS

The devastating effect on nations of the COVID-19 pandemic has helped to highlight the potential far-reaching benefits that many vaccination programmes can offer. This VoV framework is particularly relevant to policy decisions considering EE, and the potential future expansion of non-pandemic vaccination value considerations. The framework helps to understand and compare current value considerations across countries and payer versus societal perspectives. It provides decision-makers with a transparent and logical path to broaden consideration of VoV in EE.

Towards a Broader Assessment of Value in Vaccines: The BRAVE Way Forward

BACKGROUND

The COVID-19 pandemic shows that the impact of effective vaccines can extend well beyond vaccinated individuals and healthcare systems. Yet, these broader value elements are not typically considered in Health Technology Assessment (HTA) which may underestimate vaccines' broader value.

OBJECTIVES

This study aimed to (1) describe the gap between broader value elements identified in value frameworks for vaccines and those recognised in HTA of vaccines in nine developed markets, and (2) develop expert-informed, consensus-based recommendations on how hurdles for broader value recognition could be overcome.

METHODS

We used a four-step modified Delphi method consisting of literature research (phase I, pearl-growing approach using PubMed Web of Science and Google covering the years 2000-2019), two consecutive phases of expert elicitation (phase II and III, including two email surveys and one virtual round table with 10 experts from 9 countries) and synthesis of recommendations (phase IV).

RESULTS

Results show that about half of the broader value elements relevant to vaccines are not (consistently) considered in HTA processes of multiple higher-income countries. Experts identified five priority areas for broader value recognition, including considering (1) more comprehensive cost offsets within the health care system, (2) carer quality of life, (3) transmission value, (4) prevention of antimicrobial resistance and (5) macroeconomic effects.

CONCLUSION

To achieve a broader recognition of the value of vaccines, a three-pronged approach was recommended, focusing on (1) Evidence: proactively steering generation of high-quality evidence to quantify the broader value of vaccines to society; (2) Ability: leveraging and further developing existing methodological and analytic expertise to appropriately recognise the broad value of vaccines within HTA processes; (3) Willingness: Stimulating stakeholder engagement to change the status quo and move towards more transparent and comprehensive value assessment processes for vaccines globally.

Realising the broader value of vaccines in the UK

Many health technology assessment (HTA) agencies limit their assessments of vaccines to the health benefits for the vaccinated individual, the costs associated with vaccine administration and the disease avoided. However, because the value of vaccines tends to accrue to a large extent beyond the vaccinated individual, they are systematically undervalued in many current HTA processes. This is also the case in the UK, where the Joint Committee on Vaccination and Immunisation (JCVI) is in charge of assessing preventative vaccines, while therapeutic vaccines fall in the realm of the National Institute for Clinical Excellence (NICE).

To contribute to a forward-looking perspective, we designed a framework to capture the broader value of vaccination. We reviewed the current state of the global vaccines pipeline and selected seven preventative and three therapeutic vaccines that are likely to enter the UK market within five years. We assessed on which value elements the selected vaccines would potentially generate value, and compared those against the novel broader value framework. A review of the current value elements considered by the JCVI and NICE allowed identifying the critical gaps between potential value generation and value recognition.

To our knowledge, this is the first time that the broader value of vaccination has been pro-actively assessed for pipeline vaccinations. Our findings show that the existing narrow evaluation frameworks are likely to systematically undervalue the value of potential future vaccines coming to the UK market. This is particularly relevant, where their impact on AMR and other health interventions, and on the productivity of the workforce is of concern. Recommendations to overcome this include an explicit and more consistent inclusion of, and data collection on, the impact of vaccines on AMR and other health interventions by JCVI and NICE; the consideration of a societal perspective and the fiscal impact of vaccines to societies.

Use of Cost-Effectiveness Analyses for Decisions About Vaccination Programs for Meningococcal Disease in the United States, United Kingdom, The Netherlands, and Canada

INTRODUCTION

Meningococcal vaccines to protect against invasive meningococcal disease (IMD) vary in terms of vaccine technology and serogroup coverage (Polysaccharide MnACWY, conjugated C and ACWY, outer membrane vesicle-based or protein-based B vaccines), and the national recommendations for each of them vary in terms of target population and number of doses. We sought to understand factors associated with the evolution of meningococcal vaccination program recommendations in four countries with formal evaluation processes: the UK, US, the Netherlands, and Canada.

AREAS COVERED

A targeted review of published literature and internet sources for the four countries relating to meningococcal vaccination decision-making was conducted. The review focused on the impact of cost-effectiveness analyses on vaccine policy decisions and the extent to which variation in incidence of IMD and its potential catastrophic consequences influenced policy decisions.The evolution of meningococcal vaccine recommendations in the four countries was mainly driven by changes in vaccine availability and changes in serogroup incidence. Public pressure due to the catastrophic nature of IMD influenced recommendations. The role of cost-effectiveness analyses varied across the 4 countries.

EXPERT OPINION

The value of implementing meningococcal vaccination programs should be assessed using factors beyond those included in traditional cost-effectiveness analyses.

Evaluating Vaccination Programs That Prevent Diseases With Potentially Catastrophic Health Outcomes: How Can We Capture the Value of Risk Reduction?

In the last 5 years, guidelines have been developed for performing cost-effectiveness analyses (CEAs) for the economic evaluation of vaccination programs against infectious diseases. However, these cost-effectiveness guidelines do not provide specific guidance for including the value of reducing the risk of rare but potentially catastrophic health outcomes, such as mortality or long-term sequelae. Alternative economic evaluation methods, including extended CEA, the impact inventory, cost-benefit analyses, willingness to pay or the value of a statistical life, to capture the value of this risk reduction could provide more complete estimates of the value of vaccination programs for diseases with potentially catastrophic health and nonhealth outcomes. In this commentary, using invasive meningococcal disease as an example, we describe these alternative approaches along with examples to illustrate how the benefits of vaccination in reducing risk of catastrophic health outcomes can be valued. These benefits are not usually captured in CEAs that only include population benefits estimated as the quality-adjusted life-years gained and reduced costs from avoided cases.

Health Technology Assessment for Vaccines Against Rare, Severe Infections: Properly Accounting for Serogroup B Meningococcal Vaccination's Full Social and Economic Benefits

The high price of new generations of vaccines relative to their predecessors has become an important consideration in debates over whether the benefits of the new vaccines justify their costs. An increasingly central line of inquiry in the literature on valuing vaccination surrounds accounting for the full social and economic benefits of vaccination. This paper applies this emerging perspective to the particular case of vaccination against serogroup B meningococcal disease (MenB). We explore key issues involved in health technology assessments of MenB vaccination, which have led to pronounced heterogeneity in evaluation methods and recommendation outcomes across countries such as France, Germany, the US, and the UK. Accounting for typically neglected sources of socioeconomic benefit could potentially impact recommendation and reimbursement decisions. We propose a taxonomy of such benefits built around four dimensions: (i) internalized health benefits, (ii) internalized non-health benefits, (iii) externalized health benefits, and (iv) externalized non-health benefits. This approach offers a systematic, comprehensive evaluation framework that can be used in future assessment of MenB vaccines as well as other health technologies.

Economic evaluation of meningococcal vaccines: considerations for the future

In 2018, a panel of health economics and meningococcal disease experts convened to review methodologies, frameworks, and decision-making processes for economic evaluations of vaccines, with a focus on evaluation of vaccines targeting invasive meningococcal disease (IMD). The panel discussed vaccine evaluation methods across countries; IMD prevention benefits that are well quantified using current methods, not well quantified, or missing in current cost-effectiveness methodologies; and development of recommendations for future evaluation methods. Consensus was reached on a number of points and further consideration was deemed necessary for some topics. Experts agreed that the unpredictability of IMD complicates an accurate evaluation of meningococcal vaccine benefits and that vaccine cost-effectiveness evaluations should encompass indirect benefits, both for meningococcal vaccines and vaccines in general. In addition, the panel agreed that transparency in the vaccine decision-making process is beneficial and should be implemented when possible. Further discussion is required to ascertain: how enhancing consistency of frameworks for evaluating outcomes of vaccine introduction can be improved; reviews of existing tools used to capture quality of life; how indirect costs are considered within models; and whether and how the weighting of quality-adjusted life-years (QALY), application of QALY adjustment factors, or use of altered cost-effectiveness thresholds should be used in the economic evaluation of vaccines.

Commentary: Why Has Uptake of Pneumococcal Vaccines for Children Been So Slow? The Perils of Undervaluation

Pediatric pneumococcal disease exacts a substantial burden on global health, much of which is vaccine-preventable. Despite this considerable burden and the demonstrably high efficacy of pneumococcal conjugate vaccines (PCVs), the overall level of PCV uptake remains concerningly low, especially compared with that of other childhood-recommended vaccines, such as tuberculosis and polio. A broad set of plausible explanations exists for this low uptake, including logistical challenges, psychosocial factors and affordability. One additional and systematic cause of low uptake, which is the focus of our discussion, is economists' and policymakers' tendency to undervalue vaccination in general by adopting a narrow health sector perspective when performing economic evaluations of vaccines. We present an alternative, societal framework for economic evaluations that encompasses a broader set of socioeconomic benefits in addition to health benefits. Quantifying a more comprehensive taxonomy of PCV's benefits will help to address potential undervaluation and may be sufficient not only to justify recommendation and reimbursement but also to stimulate efforts and investment toward closing coverage gaps.

Cost-effectiveness of alternative strategies for vaccination of adolescents against serogroup B IMD with the MenB-FHbp vaccine in Canada

OBJECTIVE

Serogroup B meningococci (MnB) are now the largest cause of invasive meningococcal disease (IMD) in Canada. We assessed the clinical and economic impact of 3 adolescent MenB-FHbp immunization strategies.

METHODS

A population-based dynamic transmission model was developed to simulate the transmission of MnB among the entire Canadian population over a 30-year time horizon. Age group-based IMD incidence, bacterial carriage and transmission, disease outcomes, costs, and impact on quality of life were obtained from Canadian surveillance data and published literature. The vaccine was assumed to provide 85% protection against IMD and 26.6% against carriage acquisition. The model estimated the impact of routine vaccination with MenB-FHbp in 3 strategies: (1) age 14, along with existing school-based programs, with 75% uptake; (2) age 17 with 75% uptake, assuming school vaccination; and (3) age 17 with 30% uptake, assuming vaccination outside of school. Costs were calculated from the Canadian societal perspective.

RESULTS

With no vaccination, an estimated 3974 MnB cases would be expected over 30 years. Vaccination with strategies 1-3 were estimated to avert 688, 1033, and 575 cases, respectively. These outcomes were associated with incremental costs per quality-adjusted life-year of $976,000, $685,000, and $490,000.

CONCLUSIONS

Our model indicated that if the vaccine reduces risk of carriage acquisition, vaccination of older adolescents, even at lower uptake, could have a significant public health impact. Due to low disease incidence, MnB vaccination is unlikely to meet widely accepted cost-effectiveness thresholds, but evaluations of new programs should consider the overall benefits of the vaccination.

A review of the cost-effectiveness of adult influenza vaccination and other preventive services

The Centers for Disease Control and Prevention recommend annual influenza vaccination of persons ≥6 months old. However, in 2016-17, only 43.3% of U.S. adults reported receiving an influenza vaccination. Limited awareness about the cost-effectiveness (CE) or the economic value of influenza vaccination may contribute to low vaccination coverage. In 2017, we conducted a literature review to survey estimates of the CE of influenza vaccination of adults compared to no vaccination. We also summarized CE estimates of other common preventive interventions that are recommended for adults by the U.S. Preventive Services Task Force. Results are presented as costs in US$2015 per quality-adjusted life-year (QALY) saved. Among adults aged 18-64, the CE of influenza vaccination ranged from $8000 to $39,000 per QALY. Assessments for adults aged ≥65 yielded lower CE ratios, ranging from being cost-saving to $15,300 per QALY. Influenza vaccination was cost-saving to $85,000 per QALY for pregnant women in moderate or severe influenza seasons and $260,000 per QALY in low-incidence seasons. For other preventive interventions, CE estimates ranged from cost-saving to $170,000 per QALY saved for breast cancer screening among women aged 50-74, from cost-saving to $16,000 per QALY for colorectal cancer screening, and from $27,000 to $600,000 per QALY for hypertension screening and treatment. Influenza vaccination in adults appears to have a similar CE profile as other commonly utilized preventive services for adults. Efforts to improve adult vaccination should be considered by adult-patient providers, healthcare systems and payers given the health and economic benefits of influenza vaccination.

Analytic Considerations in Applying a General Economic Evaluation Reference Case to Gene Therapy

The concept of a reference case, first proposed by the US Panel on Cost-Effectiveness in Health and Medicine, has been used to specify the required methodological features of economic evaluations of healthcare interventions. In the case of gene therapy, there is a difference of opinion on whether a specific methodological reference case is required. The aim of this article was to provide a more detailed analysis of the characteristics of gene therapy and the extent to which these characteristics warrant modifications to the methods suggested in general reference cases for economic evaluation. We argue that a completely new reference case is not required, but propose a tailored checklist that can be used by analysts and decision makers to determine which aspects of economic evaluation should be considered further, given the unique nature of gene therapy.

Towards a more comprehensive approach for a total economic assessment of vaccines?: 1. The building blocks for a health economic assessment of vaccination

​Since we were born, we all take preventative actions to avoid unpredictable adverse conditions. Some actions are done automatically. Others require a conscious choice , either for personal or social benefit. A distinction can therefore be drawn between non-active and active prevention, and between individual and social prevention. Active prevention requires making a choice in time, effort, and cost. We call it an economic choice. Vaccines belong to the group of active and social prevention. Because a vaccination program is an economic social choice, how should it be valued, and what cost should we pay for? To date, the economic evaluations developed for treatment have been applied to vaccines. However, over 25 different characteristics differentiate vaccines from treatment. For example, the benefit of vaccination is measured at the population level not at the individual level, the main effect of prevention is societal and not an individual-based gain only, and the biggest hurdle to implement a new vaccine is the initial budget investment and not so much its estimated 'value for money'. This makes the current application of incremental cost-utility analysis difficult for vaccines for a comprehensive evaluation. New approaches may be needed to capture the full economic benefit of vaccines.​.

2. How is the economic assessment of vaccines performed today?

This paper describes how the economic assessment of vaccines is performed today. It discusses why it may be incomplete and explores potential approaches to adjust the analysis to be more comprehensive. Besides helping protect against serious disease, vaccines also help avoid mild disease episodes that may not receive medical attention but which have important societal consequences. They also benefit unvaccinated individuals by reducing disease transmission. Wider societal benefits may extend beyond a decrease in disease incidence, as lower transmission rates reduce the risk of epidemics, which in turn reduces the pressure on healthcare providers, and may improve the quality of care for patients with unrelated diseases. Vaccines also lower the use of antibiotics leading to less pressure on anti-microbial resistance. Conventional ICUA focuses on individual health benefits, like increased survival. Therefore, this approach may not adequately capture the wider vaccination benefits. We discuss differences between treatment and vaccine prevention in the economic assessment, and how ICUA has been adapted to cope with the inconsistencies. Although such adaptations may fulfil the demand of one specific stakeholder, they may not meet the needs of other stakeholders who operate at the societal level, such as ministries other than healthcare, employers, caregivers, and insurers.

Measurement and valuation of health providers' time for the management of childhood pneumonia in rural Malawi: an empirical study

BACKGROUND

Human resources are a major cost driver in childhood pneumonia case management. Introduction of 13-valent pneumococcal conjugate vaccine (PCV-13) in Malawi can lead to savings on staff time and salaries due to reductions in pneumonia cases requiring admission. Reliable estimates of human resource costs are vital for use in economic evaluations of PCV-13 introduction.

METHODS

Twenty-eight severe and twenty-four very severe pneumonia inpatients under the age of five were tracked from admission to discharge by paediatric ward staff using self-administered timesheets at Mchinji District Hospital between June and August 2012. All activities performed and the time spent on each activity were recorded. A monetary value was assigned to the time by allocating a corresponding percentage of the health workers' salary. All costs are reported in 2012 US$.

RESULTS

A total of 1,017 entries, grouped according to 22 different activity labels, were recorded during the observation period. On average, 99 min (standard deviation, SD = 46) were spent on each admission: 93 (SD = 38) for severe and 106 (SD = 55) for very severe cases. Approximately 40 % of activities involved monitoring and stabilization, including administering non-drug therapies such as oxygen. A further 35 % of the time was spent on injecting antibiotics. Nurses provided 60 % of the total time spent on pneumonia admissions, clinicians 25 % and support staff 15 %. Human resource costs were approximately US$ 2 per bed-day and, on average, US$ 29.5 per severe pneumonia admission and US$ 37.7 per very severe admission.

CONCLUSIONS

Self-reporting was successfully used in this context to generate reliable estimates of human resource time and costs of childhood pneumonia treatment. Assuming vaccine efficacy of 41 % and 90 % coverage, PCV-13 introduction in Malawi can save over US$ 2 million per year in staff costs alone.

Hitting the Optimal Vaccination Percentage and the Risks of Error: Why to Miss Right

OBJECTIVE

To determine the optimal level of vaccination coverage defined as the level that minimizes total costs and explore how economic results change with marginal changes to this level of coverage.

METHODS

A susceptible-infected-recovered-vaccinated model designed to represent theoretical infectious diseases was created to simulate disease spread. Parameter inputs were defined to include ranges that could represent a variety of possible vaccine-preventable conditions. Costs included vaccine costs and disease costs. Health benefits were quantified as monetized quality adjusted life years lost from disease. Primary outcomes were the number of infected people and the total costs of vaccination. Optimization methods were used to determine population vaccination coverage that achieved a minimum cost given disease and vaccine characteristics. Sensitivity analyses explored the effects of changes in reproductive rates, costs and vaccine efficacies on primary outcomes. Further analysis examined the additional cost incurred if the optimal coverage levels were not achieved.

RESULTS

Results indicate that the relationship between vaccine and disease cost is the main driver of the optimal vaccination level. Under a wide range of assumptions, vaccination beyond the optimal level is less expensive compared to vaccination below the optimal level. This observation did not hold when the cost of the vaccine cost becomes approximately equal to the cost of disease.

DISCUSSION AND CONCLUSION

These results suggest that vaccination below the optimal level of coverage is more costly than vaccinating beyond the optimal level. This work helps provide information for assessing the impact of changes in vaccination coverage at a societal level.

Response of immune response genes to adjuvants poly [di(sodium carboxylatoethylphenoxy)phosphazene] (PCEP), CpG oligodeoxynucleotide and emulsigen at intradermal injection site in pigs

Understanding the mechanisms by which adjuvants mediate their effects provide critical information on how innate immunity influences the development of adaptive immunity. Despite being a critical vaccine component, the mechanisms by which adjuvants mediate their effects are not fully understood and this is especially true when they are used in large animals. This lack of understanding limits our ability to design effective vaccines. In the present study, we administered polyphosphazene (PCEP), CpG oligodeoxynucleotides (CpG), emulsigen or saline via an intradermal injection into pigs and assessed the impact on the expression of reported 'adjuvant response genes' over time. CpG induced a strong upregulation of the chemokine CXL10 several 'Interferon Response Genes', as well as TNFα, and IL-10, and a down-regulation of IL-17 genes. Emulsigen upregulated expression of chemokines CCL2 and CCL5, proinflammatory cytokines IL-6 and TNFα, as well as TLR9, and several IFN response genes. PCEP induced the expression of chemokine CCL2 and proinflammatory cytokine IL-6. These results suggest that emulsigen and CpG may promote recruitment of innate immune cells and Th1 type cytokine production but that PCEP may promote a Th-2 type immune response through the induction of IL-6, an inducer of B cell activity and differentiation.

Methods for Health Economic Evaluation of Vaccines and Immunization Decision Frameworks: A Consensus Framework from a European Vaccine Economics Community

BACKGROUND

Incremental cost-effectiveness and cost-utility analyses [health economic evaluations (HEEs)] of vaccines are routinely considered in decision making on immunization in various industrialized countries. While guidelines advocating more standardization of such HEEs (mainly for curative drugs) exist, several immunization-specific aspects (e.g. indirect effects or discounting approach) are still a subject of debate within the scientific community.

OBJECTIVE

The objective of this study was to develop a consensus framework for HEEs of vaccines to support the development of national guidelines in Europe.

METHODS

A systematic literature review was conducted to identify prevailing issues related to HEEs of vaccines. Furthermore, European experts in the field of health economics and immunization decision making were nominated and asked to select relevant aspects for discussion. Based on this, a workshop was held with these experts. Aspects on 'mathematical modelling', 'health economics' and 'decision making' were debated in group-work sessions (GWS) to formulate recommendations and/or--if applicable--to state 'pros' and 'contras'.

RESULTS

A total of 13 different aspects were identified for modelling and HEE: model selection, time horizon of models, natural disease history, measures of vaccine-induced protection, duration of vaccine-induced protection, indirect effects apart from herd protection, target population, model calibration and validation, handling uncertainty, discounting, health-related quality of life, cost components, and perspectives. For decision making, there were four aspects regarding the purpose and the integration of HEEs of vaccines in decision making as well as the variation of parameters within uncertainty analyses and the reporting of results from HEEs. For each aspect, background information and an expert consensus were formulated.

CONCLUSIONS

There was consensus that when HEEs are used to prioritize healthcare funding, this should be done in a consistent way across all interventions, including vaccines. However, proper evaluation of vaccines implies using tools that are not commonly used for therapeutic drugs. Due to the complexity of and uncertainties around vaccination, transparency in the documentation of HEEs and during subsequent decision making is essential.

Valuing vaccines: deficiencies and remedies

Current evaluation models for the value of vaccines typically account for a small subset of the full social and economic benefits of vaccination. Health investments yield positive economic benefits via several channels at the household, community, and national levels. Underestimating, or worse, not considering these benefits can lead to ill-founded recommendations regarding the introduction of vaccines into immunization programs. The clear and strong links between health and wealth suggest the need to redesign valuation frameworks for vaccination so that the full costs may be properly weighed against the full benefits of vaccines.

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.

Mind the gaps: what's missing from current economic evaluations of universal HPV vaccination?

BACKGROUND

Since the original licensing of human papilloma virus (HPV) vaccination for women, evidence is accumulating of its effectiveness in preventing HPV-related conditions in men, and universal vaccination (vaccinating men and women) is now recommended in some countries. Several models of the cost-effectiveness of universal HPV vaccination have been published, but results have been mixed. This article assesses the extent to which economic studies have captured the range of values associated with universal HPV vaccination, and how this influences estimates of its cost-effectiveness.

METHODS

Eight published economic evaluations of universal HPV vaccination were reviewed to identify which of the values associated with universal HPV vaccination were included in each analysis.

RESULTS

Studies of the cost-effectiveness of universal HPV vaccination capture only a fraction of the values generated. Most studies focused on impacts on health and health system cost, and only captured these partially. A range of values is excluded from most studies, including impacts on productivity, patient time and costs, carers and family costs, and broader social values such as the right to access treatment. Further, those studies that attempted to capture these values only did so partially.

DISCUSSION

Decisions to invest in universal HPV vaccination need to be based on a complete assessment of the value that it generates. This is not provided by existing economic evaluations. Further work is required to understand this value. First, research is required to understand how HPV-related health outcomes impact on society including, for instance, their impact on productivity. Second, consideration should be given to alternative approaches to capture this broader set of values in a manner useful to decisions-makers, such as multi-criteria decision analysis.

[Vaccination coverage in German adults: results of the German Health Interview and Examination Survey for Adults (DEGS1)]

In the absence of an immunisation register, vaccination coverage in Germany must be estimated. Ten years after the German National Health Interview and Examination Survey 1998 (GNHIES98), the population survey DEGS1 is one of the data sources to be used for monitoring vaccination coverage. In the survey, data on vaccination history were obtained from vaccination cards and self-reports. The prevalence of immunisation for tetanus and diphtheria was higher compared to the prevalence estimated ten years previously in GNHIES98. Nonetheless, 28.6 % of adults have not been vaccinated against tetanus and 42.9 % have not been vaccinated against diphtheria within the last ten years. Vaccination is especially low among the elderly, among adults with low socio-economic status and in western Germany. During the last ten years, only 11.8 % of women and 9.4 % of men were vaccinated against pertussis in western Germany; vaccination coverage was twice as high in eastern Germany. In 2009, recommendations were published to combine the next tetanus immunisation with a pertussis immunisation; therefore pertussis vaccination coverage might improve in the coming years. The lifetime prevalence of influenza vaccination obtained in DEGS1 is higher than the annual vaccination rate for influenza. However, the lifetime prevalence among adults aged 60 years or older is still below the annual rate of 75 % recommended by the WHO. An English full-text version of this article is available at SpringerLink as supplemental.

A critical review of cost-effectiveness analyses of vaccinating males against human papillomavirus

A critical review of cost-effectiveness analyses of HPV vaccination in males was conducted and nine studies were identified in different countries. Due to the heterogeneity among these studies in terms of modeling approach, vaccination strategies, health outcomes considered, assumptions and parameters, limited conclusions can be drawn with regard to the absolute cost-effectiveness. Nevertheless, key drivers were identified. More favorable cost-effectiveness appeared when all HPV-related diseases outcomes were considered, a suboptimal vaccine coverage among girls and/or lower vaccine prices were assumed. There was a general lack of transparency to fully describe the details of the methodological approach of modeling and calibration. Further research should be conducted to generate robust evidence-based data sets (HPV-related diseases epidemiology, costs and quality of life). The best modeling practice for HPV vaccination and how to better capture the true economic value of vaccination beyond cost-effectiveness in a broader policy context need to be investigated.

Economic evaluations of hepatitis A vaccination in middle-income countries

Economic evaluations of hepatitis A vaccination are important to assist national and international policy makers in different jurisdictions on making effective decisions. Up to now, a comprehensive review of the potential health and economic benefits on hepatitis A vaccination in middle-income countries (MICs) has not been performed yet. In this study, we reviewed the literature on the cost-effectiveness of hepatitis A vaccination in MICs. Most of the studies confirmed that hepatitis A vaccination was cost effective or even cost saving under certain conditions. We found that vaccine price, medical costs, incidence and discount rate were the most influential parameters on the sensitivity analyses. Vaccine price has been shown as a barrier for MICs in implementing universal vaccination of hepatitis A. Given their relatively limited financial resources, implementation of single-dose vaccination could be considered. Despite our findings, we argue that further economic evaluations in MICs are still required in the near future.

Economic evaluation of vaccines: specificities and future challenges illustrated by recent European examples

This study reviews the current challenges in the economic evaluation of vaccines with a focus on European countries. In particular, the type of clinical evidence generally available, the impact of discounting for time preference and the use of modeling to derive valid cost-effectiveness assessments are considered. First, the characteristics of evidence for vaccines are discussed, as well as potential difficulties faced when using evidence-based medicine applied to curative drugs to interpret vaccine evidence. Then, discounting is considered and specific examples illustrating issues with different types of discounting are described, taking HPV as the example. Finally, the need for sometimes complex dynamic models for vaccines is explored, and specific types of models are reviewed, keeping into consideration the adage "complex when needed, straightforward if allowed."

Health economic evaluation of vaccination strategies for the prevention of herpes zoster and postherpetic neuralgia in Germany

BACKGROUND

Herpes zoster (HZ) is a self-limiting painful skin rash affecting mostly individuals from 50 years of age. The main complication is postherpetic neuralgia (PHN), a long-lasting pain after rash has resolved. A HZ-vaccine has recently been licensed in Europe for individuals older than 50 years. To support an informed decision-making for a potential vaccination recommendation, we conducted a health economic evaluation to identify the most cost-effective vaccination strategy.

METHODS

We developed a static Markov-cohort model, which compared a vaccine-scenario with no vaccination. The cohort entering the model was 50 years of age, vaccinated at age 60, and stayed over life-time in the model. Transition probabilities were based on HZ/PHN-epidemiology and demographic data from Germany, as well as vaccine efficacy (VE) data from clinical trials. Costs for vaccination and HZ/PHN-treatment (in Euros; 2010), as well as outcomes were discounted equally with 3% p.a. We accounted results from both, payer and societal perspective. We calculated benefit-cost-ratio (BCR), number-needed-to-vaccinate (NNV), and incremental cost-effectiveness ratios (ICERs) for costs per HZ-case avoided, per PHN-case avoided, and per quality-adjusted life-year (QALY) gained. Different target age-groups were compared to identify the most cost-effective vaccination strategy. Base-case-analysis as well as structural, descriptive-, and probabilistic-sensitivity-analyses (DSA, PSA) were performed.

RESULTS

When vaccinating 20% of a cohort of 1 million 50 year old individuals at the age of 60 years, approximately 20,000 HZ-cases will be avoided over life-time. The NNV to avoid one HZ (PHN)-case was 10 (144). However, with a BCR of 0.34 this vaccination-strategy did not save costs. The base-case-analysis yielded an ICER of 1,419 (20,809) Euros per avoided HZ (PHN)-case and 28,146 Euros per QALY gained. Vaccination at the age of 60 was identified in most (sensitivity) analyses to be the most cost-effective vaccination strategy. In DSA, vaccine price and VE were shown to be the most critical input-data.

CONCLUSIONS

According to our evaluation, HZ-vaccination is expected to avoid HZ/PHN-cases and gain QALYs to higher costs. However, the vaccine price had the highest impact on the ICERs. Among different scenarios, targeting individuals aged 60 years seems to represent the most cost-effective vaccination-strategy.

A novel method to value real options in health care: the case of a multicohort human papillomavirus vaccination strategy

BACKGROUND

A large number of economic evaluations have already confirmed the cost-effectiveness of different human papillomavirus (HPV) vaccination strategies. Standard analyses might not capture the full economic value of novel vaccination programs because the cost-effectiveness paradigm fails to take into account the value of active management. Management decisions can be seen as real options, a term used to refer to the application of option pricing theory to the valuation of investments in nonfinancial assets in which much of the value is attributable to flexibility and learning over time.

OBJECTIVE

The aim of this article was to discuss the potential advantages shown by using the payoff method in the valuation of the cost-effectiveness of competing HPV immunization programs.

METHODS

This was the first study, to the best of our knowledge, to use the payoff method to determine the real option values of 4 different HPV vaccination strategies targeting female subjects aged 12, 15, 18, and 25 years. The payoff method derives the real option value from the triangular payoff distribution of the project's net present value, which is treated as a triangular fuzzy number. To inform the real option model, cost-effectiveness data were derived from an empirically calibrated Bayesian model designed to assess the cost-effectiveness of a multicohort HPV vaccination strategy in the context of the current cervical cancer screening program in Italy. A net health benefit approach was used to calculate the expected fuzzy net present value for each of the 4 vaccination strategies evaluated.

RESULTS

Costs per quality-adjusted life-year gained seemed to be related to the number of cohorts targeted: a single cohort of girls aged 12 years (€10,955 [95% CI, -1,021 to 28,212]) revealed the lowest cost among the 4 alternative strategies evaluated. The real option valuation challenged the cost-effectiveness dominance of a single cohort of 12-year-old girls. The simultaneous vaccination of 2 cohorts of girls aged 12 and 15 years yielded a real option value (€17,723) equivalent to that attributed to a single cohort of 12-year-old girls (€17,460).

CONCLUSIONS

The payoff method showed distinctive advantages in the valuation of the cost-effectiveness of competing health care interventions, essentially determined by the replacement of the nonfuzzy numbers that are commonly used in cost-effectiveness analysis models, with fuzzy numbers as an input to inform the real option pricing method. The real option approach to value uncertainty makes policy making in health care an evolutionary process and creates a new "space" for decision-making choices.

Meningococcal serogroup A, C, W₁₃₅ and Y conjugated vaccine: a cost-effectiveness analysis in the Netherlands

Background

In 2002, vaccination with a serogroup C meningococcal conjugate vaccine (MenC) was introduced in the Netherlands for all children aged 14 months. Despite its success, herd immunity may wane over time. Recently, a serogroup A,C,W135,Y meningococcal conjugate vaccine (MenACWY) was licensed for use in subjects of 12 months of age and above.

Objectives

To evaluate the cost-effectiveness of meningococcal vaccination at 14 months and an additional vaccination at the age of 12 years, both with the MenACWY vaccine.

Methods

A decision analysis cohort model, with 185,000 Dutch newborns, was used to evaluate the cost-effectiveness of different immunization strategies. For strategies including a vaccination at 12 years of age, an additional cohort with adolescents aged 12 years was followed. The incremental cost-effectiveness ratio (ICER) was estimated for the current disease incidence and for a scenario when herd immunity is lost.

Results

Vaccination with MenACWY at 14 months is cost-saving. Vaccinating with MenACWY at 14 months and at 12 years would prevent 7 additional cases of meningococcal serogroup A,C,W135,Y disease in the birth cohort and adolescent cohort followed for 99 years compared to the current vaccine schedule of a single vaccination with MenC at 14 months. With the current incidence, this strategy resulted in an ICER of €635,334 per quality adjusted life year. When serogroup C disease incidence returns to pre-vaccination levels due to a loss of vaccine-induced herd-immunity, vaccination with MenACWY at 14 months and at 12 years would be cost-saving.

Conclusions

Routine vaccination with MenACWY is cost-saving. With the current epidemiology, a booster-dose with MenACWY is not likely cost-effective. When herd immunity is lost, a booster-dose has the potential of being cost-effective. A dynamic model should be developed for more precise estimation of the cost-effectiveness of the prevention of disappearance of herd immunity.

Economics of vaccines revisited

Performing a total health economic analysis of a vaccine newly introduced into the market today is a challenge when using the conventional cost-effectiveness analysis we normally apply on pharmaceutical products. There are many reasons for that, such as: the uncertainty in the total benefit (direct and indirect) to be measured in a population when using a cohort model; (1) appropriate rules about discounting the long-term impact of vaccines are absent jeopardizing therefore their value at the initial investment; (2) the presence of opposite contexts when introducing the vaccine in developed vs. the developing world with high benefits, low initial health care investment for the latter vs. marginal benefit and high cost for the former; with a corresponding paradox for the vaccine becoming very cost-effective in low income countries but rather medium in middle low to high middle income countries; (3) and the type of trial assessment for the newer vaccines is now often performed with immunogenicity reaction instead of clinical endpoints which still leaves questions on their real impact and their head-to-head comparison. (4.)

Categorization of methods used in cost-effectiveness analyses of vaccination programs based on outcomes from dynamic transmission models

The aim of this study is to categorize methods used to estimate the cost-effectiveness of vaccination programs using dynamic transmission models, and assess value to decision-makers. A targeted literature search of PubMed has been carried out for this purpose. A review of 43 articles presenting cost-effectiveness analyses of vaccination programs based on dynamic transmission models identified four methods for the estimation of a cost-effectiveness ratio: cumulative population values over a fixed time horizon; population values for a steady-state year; cohort values from time of program initiation; and cohort values at steady state. Cost-effectiveness estimates are sensitive to the choice of time horizon or number of cohorts included. Estimates at steady state are the most comparable to estimates for other healthcare interventions but do not account for pre-steady-state periods. Population values provide estimates of budget impact. In conclusion, four different methods were identified for converting clinical outcomes from a dynamic transmission model to cost-effectiveness estimates. Sensitivity analyses for time horizon or number of cohorts considered should be routinely performed.

On discounting of health gains from human papillomavirus vaccination: effects of different approaches

OBJECTIVES

Discounting has long been a matter of controversy in the field of health economic evaluations. How to weigh future health effects has resulted in ongoing discussions. These discussions are imminently relevant for health care interventions with current costs but future benefits. Different approaches to discount health effects have been proposed. In this study, we estimated the impact of different approaches for discounting health benefits of human papillomavirus (HPV) vaccination.

METHODS

An HPV model was used to estimate the impact of different discounting approaches on the present value of health effects. For the constant discount approaches, we varied the discount rate for health effects ranging from 0% to 4%. Next, the impact of relevant alternative discounting approaches was estimated, including hyperbolic, proportional, stepwise, and time-shifted discounting.

RESULTS

The present value of health effects gained through HPV vaccination varied strongly when varying discount rates and approaches. The application of the current Dutch guidelines resulted in a present value of health effects that was eight or two times higher than that produced when using the proportional discounting approach or when using the internationally more common 4% discount rate for health effects, respectively. Obviously, such differences translate into large variations in corresponding incremental cost-effectiveness ratios.

CONCLUSION

The exact discount rate and approach chosen in an economic evaluation importantly impact the projected value of health benefits of HPV vaccination. Investigating alternative discounting approaches in health-economic analysis is important, especially for vaccination programs yielding health effects far into the future. Our study underlines the relevance of ongoing discussions on how and at what rates to discount.

The pharmacoeconomics of pneumococcal conjugate vaccines in Latin America

Streptococcus pneumoniae continues to be the most important causative agent of invasive bacterial infections in children and is the most common cause of vaccine-preventable deaths in children less than 5 years of age. Due to some conditions in the Latin America region, economic assessments of pneumococcal conjugate vaccines (PCVs) have unique characteristics. First, distribution of S. pneumoniae serotypes, and thus coverage by vaccines that incorporate certain serotypes, varies within the region and compared with other parts of the world. Second, the mortality rate of pneumococcal infections in developing countries is significantly higher than in the US and Europe. Third, the economies of the Latin American region are very different from those of developed countries. For these reasons, the Pan American Health Organization (PAHO) is promoting the need for economic valuation studies of the impact of pneumococcal vaccines Latin America. Given the importance of pneumonia in the burden of pneumococcal disease in Latin America, the number of pneumonia cases prevented by the vaccine has a large impact on the economic valuation of PCVs, due to a strong correlation with numbers of deaths averted, quality-adjusted life-years (QALYs) gained or disability-adjusted life-years (DALYs) avoided. In terms of cost, analysis of impact on acute otitis media (short-term) and sequelae (long-term) show a significant and important expenditure avoided by vaccination. Cost-effectiveness is significantly modified by vaccine cost, mortality due to pneumonia, vaccine efficacy/effectiveness and herd immunity. Finally the validity of certain assumptions based on the uncertainty of the data should be considered in economic assessments of new PCVs. These include assumptions related to the impact on otitis media, estimates of efficacy/effectiveness based on measured antibody levels and the extrapolation to PCV10 and PCV13 of previous experience with PCV7.

Respiratory and gastrointestinal epithelial modulation of the immune response during viral infection

Respiratory and enteric viral infections cause significant morbidity and mortality world-wide and represent a major socio-economic burden. Many of these viruses have received unprecedented public and media interest in recent years. A popular public misconception is that viruses are a threat to which the human body has only limited defences. However, the majority of primary and secondary exposures to virus are asymptomatic or induce only minor symptoms. The mucosal epithelial surfaces are the main portal of entry for viral pathogens and are centrally involved in the initiation, maintenance and polarisation of the innate and adaptive immune response to infection. This review describes the defences employed by the epithelium of the respiratory and gastrointestinal tracts during viral infections with focus on epithelial modulation of the immune response at the innate/adaptive interface.

Dynamic versus static models in cost-effectiveness analyses of anti-viral drug therapy to mitigate an influenza pandemic

Conventional (static) models used in health economics implicitly assume that the probability of disease exposure is constant over time and unaffected by interventions. For transmissible infectious diseases this is not realistic and another class of models is required, so-called dynamic models. This study aims to examine the differences between one dynamic and one static model, estimating the effects of therapeutic treatment with antiviral (AV) drugs during an influenza pandemic in the Netherlands. Specifically, we focus on the sensitivity of the cost-effectiveness ratios to model choice, to the assumed drug coverage, and to the value of several epidemiological factors. Therapeutic use of AV-drugs is cost-effective compared with non-intervention, irrespective of which model approach is chosen. The findings further show that: (1) the cost-effectiveness ratio according to the static model is insensitive to the size of a pandemic, whereas the ratio according to the dynamic model increases with the size of a pandemic; (2) according to the dynamic model, the cost per infection and the life-years gained per treatment are not constant but depend on the proportion of cases that are treated; and (3) the age-specific clinical attack rates affect the sensitivity of cost-effectiveness ratio to model choice.

Mitigation of pandemic influenza: review of cost-effectiveness studies

We conducted a review of economic evaluations of pandemic influenza control measures. In the studies found, we detected various interventions being investigated: antiviral stockpiling and treatment, prophylaxis, vaccination, school closure and restricting international travel. Cost-effectiveness varied but often showed potentials for the favorable economic profiles of these measures. Both static and dynamic models were used. We conclude that the choice of an appropriate model - in particular, a dynamic model - is crucial to arrive at valid cost-effectiveness ratios. Yet, of the economic evaluations considered here, only a few were based on dynamic modeling. We recommend that further research is directed toward linking dynamic epidemiological models for pandemic spread with economic outcomes by considering the full impacts on national economies, including direct, indirect, medical and nonmedical costs.

Methodological concerns with economic evaluations of meningococcal vaccines

The evolution of meningococcal vaccines illustrates nicely the incremental technological process that is common to much medical innovation and particularly appropriate to economic analysis. However, the economic evaluation of vaccines is complicated by several features unique to vaccines, including the possibility of indirect (herd immunity) benefits and the shear breadth of vaccination strategies available to decision makers. As with the vaccines themselves, the modelling approaches applied to the economic evaluation of meningococcal vaccines have evolved to become increasingly complex. Despite such innovation, concerns remain about the quality of economic studies of meningococcal vaccines. This article reviews evaluations of meningococcal vaccine strategies in developed countries and provides recommendations for future work in this area. Four potentially problematic areas in the existing literature are identified - indirect costs, herd immunity, quality of life and comparison programmes - and approaches to these issues are discussed. Recommendations for reporting a 'minimum analysis profile' case are also made. Although comparisons across studies are difficult at best, recent work shows that incorporating the indirect benefits and costs of vaccination substantially improves cost effectiveness.