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

Incremental net monetary benefit of herpes zoster vaccination: a systematic review and meta-analysis of cost-effectiveness evidence

OBJECTIVES

To perform a systematic review and meta-analysis to pool the incremental net benefit (INB) of each herpes zoster vaccine [i.e. Zoster Vaccine Live (ZVL) and Recombinant Zoster Vaccine (RZV)].

METHODS

We initially identified individual studies by hand-searching reference lists of the relevant systematic review articles. An updated comprehensive search was performed in Medline, Scopus, and Embase until June 2020 for additional studies. Studies were eligible if they assessed the cost-effectiveness/utility of any pair among ZVL and RZV, and no vaccine and reported economic outcomes. Details of the study characteristics, economic model inputs, costs, and outcomes were extracted. INB was calculated with monetary units adjusting for purchasing power parity for 2019 US dollars and pooled by meta-analysis.

RESULTS

A total of 37 studies were pooled for meta-analysis stratified by perspectives [i.e. societal (SP) and third-party payer (TPP)] and vaccine types. In SP, ZVL was cost-effective compared to no vaccine when vaccinated at ages of 50-59 and 70-79 years with INBs (95% CI) of $0.61 (0.37, 0.85) and $9.67 (5.20, 14.14), respectively. RZV was cost-effective for those aged 60-69 and 70-79 years with INBs of $75.61 (17.98, 133.23) and $85.01 (30.02, 140.01), respectively. In TPP, ZVL was cost-effective compared to no vaccine when vaccinated at age 70-79 years with INB of $7.57 (0.27, 14.86) and RZV was cost-effective at 60-69 years with INB $220.87 (47.80, 393.93). The cost-effectiveness of RZV was robust across a series of sensitivity analyses, but ZVL differs on different vaccination ages.

CONCLUSIONS

RZV may be cost-effective for vaccination in ages of 60-79 years for both SP and TPP perspectives, while ZVL might be cost-effective in some age groups, but results are not robust.

The Number Needed to Vaccinate (NNV) against herpes zoster: a systematic review with meta-analysis

OBJECTIVES

The number needed to vaccinate (NNV) quantifies the effectiveness of vaccination programs. We summarised the published data on NNV against herpes zoster to inform vaccination policies.

METHODS

We systematically identified studies based on a priori established and registered methods. The main outcomes were the NNV against herpes zoster infection, hospitalisation and mortality. Where appropriate, we conducted meta-analyses using inverse variance, random-effects models, pooling estimated NNV with associated 95% confidence interval (CI). Statistical heterogeneity between pooled estimates was calculated using the I² statistic.

RESULTS

Out of 229 unique citations, we included eight nonrandomized studies. Among 50+ year-olds, the NNV against herpes zoster infection using the recombinant subunit vaccine was 11 (95%CI 8-14; I² = 0%; 3 studies) and variable (I² = 94.4%; 7 studies) using live attenuated vaccine, ranging from 10 (95%CI 1-19) to 58 (95%CI 49-67). Among 65+ year-olds, the NNV against herpes zoster infection using the recombinant subunit vaccine was 12 (95%CI: 9-15; I² = 0%; 2 studies) and variable (I² = 98.5%; 4 studies) using live attenuated vaccine, ranging from 14 (95%CI 5-23) to 75 (95%CI 66-84). The NNV against herpes zoster hospitalisation among 65+ year-olds using the live attenuated vaccine was 280 (95%CI 209-352; I² = 0%; 2 studies). There was a paucity of data to inform other meta-analyses.

CONCLUSION

Evidence on the NNV against herpes zoster is scarce. Vaccination with the recombinant subunit herpes zoster vaccine may be more effective than with the live attenuated vaccine in preventing infection among 50+ year-olds. More studies are needed for a stronger evidence base for decision-making.

Vaccination for quality of life: herpes-zoster vaccines

Current vaccination policy in most high-income countries aims to counteract the decline in cell-mediated immunity to varicella zoster virus that occurs with advancing age or immunosuppression. The aim of this review was to describe the burden of illness associated with herpes zoster (HZ) and post-herpetic neuralgia (PHN) risks and their impact on the social and common life in infected people. The effectiveness/efficacy and cost effectiveness of the immunization strategy will be presented through the review of the literature relevant to the live attenuated HZ vaccine (ZLV) licensed in 2006 and the recombinant HZ vaccine (RZV). The latter has very recently been approved to protect aged people aged ≥ 50 years against HZ morbidity including its complications, and associated health-care costs. Finally, this review also provides data with respect of precautions of using and safety of ZVL and RVZ.

The Impact of Reactogenicity After the First Dose of Recombinant Zoster Vaccine on the Physical Functioning and Quality of Life of Older Adults: An Open-Label, Phase III Trial

BACKGROUND

Herpes zoster and its related complications are associated with significant medical burden, which negatively affects quality of life and daily functioning of the patients. The recently licensed recombinant zoster vaccine (RZV) offers high efficacy but is associated with local and systemic reactions. This study assessed the impact of RZV on the quality of life and daily functioning of participants and implications for caregivers.

METHODS

Four hundred and one adults aged 50 years or older received single RZV doses at 0 and 2 months in this open-label, single-arm, multicenter study (NCT02979639). Change in mean SF-36 Physical Functioning score following first-dose administration, quality of life, reactogenicity, safety, productivity loss, and health care resource utilization was assessed. The current analysis was performed post-vaccine dose-1; safety follow-up will continue until 1 year post-dose-2.

RESULTS

The most common solicited local symptoms were injection-site pain (77.5%), redness (23.0%), and swelling (13.3%); the most frequent solicited systemic reactions were fatigue (33.5%), headache (28.3%), and myalgia (26.8%). Grade 3 reactogenicity occurred in 9.5% of participants and was associated with a transient clinically important decrease in SF-36 Physical Functioning score (affecting activities such as walking, carrying groceries, climbing stairs) on Days 1 and 2 post-first vaccination. No clinically meaningful reductions in mean SF-36 Physical Functioning scale scores from pre- to post-RZV dose-1 were observed (mean +1.9 points, primary end point), and no overall quality-adjusted-life-year loss was recorded post-dose-1. Five participants reported lost workdays; caregiver workload was not increased.

CONCLUSIONS

Overall, the physical functioning and quality of life of older adults were not affected by a first RZV dose. The observed reactogenicity was consistent with previous studies.

Cost-Effectiveness of Herpes Zoster Vaccination: A Systematic Review

BACKGROUND

Herpes zoster (HZ) is one of the most common diseases among adults. Its reactivation is characterized by a severe and painful complication. In addition to the existing herpes zoster vaccine (ZVL), the FDA approved a new adjuvanted subunit zoster vaccine (RZV) in 2017 for use in adults aged 50 years and older. Several studies have assessed the cost-effectiveness of ZVL, many of which were conducted before the long-term vaccine  efficacy data was available in 2014.

OBJECTIVE

Our objectives were to (i) summarize and compare the cost-effectiveness analyses (CEAs) of ZVL conducted before and after 2014, (ii) summarize the CEAs of RZV, and (iii) critically assess the cost-effectiveness models and identify key parameters to consider for future CEAs of RZV.

METHODS

We searched PubMed and two other databases from inception to March 2018 for original cost-effectiveness, cost-utility, or cost-benefit analyses of HZ vaccines. Three investigators independently reviewed and assessed full-text articles after screening the titles and abstracts to determine eligibility. For all included studies, we assessed study quality using the Drummond and Jefferson's checklist and extracted study characteristics, model structure, vaccine characteristics, incidence of HZ and complications, incremental cost-effectiveness ratio, and sensitivity analyses. We summarized data by type of vaccine, year of publication, and funding sources.

RESULTS

Twenty-seven studies met eligibility criteria. All studies were from high-income countries and were of moderate-to-high or high quality. Twenty studies repeatedly used four cost-effectiveness models. The assumption on long-term efficacy of ZVL was not based on clinical trial data in > 50% of studies. Fifteen out of 25 studies concluded that ZVL was cost-effective compared with no vaccine at a vaccine price ranging between US$93 and US$236 per dose (2018 US$), 40% of which were published after 2014. All industry-funded studies favored the use of ZVL. The single study assessing RZV found it to be more effective and less costly than ZVL, and cost-effective compared with no vaccination. More studies conducted after 2014 included various efficacy endpoints for ZVL, adverse reactions, and productivity loss compared with those conducted before 2014.

CONCLUSIONS

A majority of studies of ZVL found it to be cost-effective compared with no vaccine using the authors' chosen willingness-to-pay thresholds. RZV was dominant in the single study comparing the two vaccines, but the finding needs to be confirmed with further studies in different settings. Future studies should assume vaccine efficacy in line with clinical data, account for more efficacy endpoints for ZVL, and include other HZ long-term complications, vaccine adverse reactions, and productivity loss.

Impact of herpes zoster and postherpetic neuralgia on the quality of life of Germans aged 50 or above

Background

Herpes zoster (HZ) is a painful dermatomal rash caused by reactivation of latent varicella zoster virus surviving in the patient’s sensory ganglia after a previous episode of varicella. The incidence of HZ increases markedly with age as does the proportion of HZ patients who develop postherpetic neuralgia (PHN) with often severe and debilitating pain persisting for months and even years.

This prospective study aimed to assess the impact of HZ and PHN on the quality of life (QoL) of individuals aged ≥ 50 years in Germany.

Methods

Patients were recruited when consulting primary care physicians for a first HZ episode. PHN was defined as a ‘worst’ pain score ≥ 3 on the Zoster Brief Pain Inventory (ZBPI) scale persisting or appearing 90 days or more after rash onset. PHN-cases were followed for up to nine months after rash onset. The interference of pain with patients’ ability to carry out normal activities was assessed by the ZBPI activities of daily living (ADL) scale and QoL by the EuroQoL five-dimension scale (EQ-5D) utility score.

Results

Of 513 patients enrolled, 61 (11.9%) developed PHN. At HZ onset, the mean ZBPI worst pain score of all patients was 5.1, the least square (LS)means estimates of the ZBPI ADL and EQ-5D utility scores were 2.970 and 0.740, respectively. Over three months follow-up, the pain scores decreased and the QoL increased monotonically across all age groups. At Day 90, the mean ZBPI worst pain score of the PHN patients was 4.4, while the LSmeans estimates of the ZBPI ADL and EQ-5D utility scores were 2.899 and 0.826, respectively. For patients with PHN persisting at nine months, the pain scores and QoL remained unchanged over the six months following the development of PHN.

Conclusion

HZ and PHN had a substantial impact on the patients’ QoL and ability to function in their normal activities. There was a clear association in time between the evolution of pain and estimated QoL. The impact on ADL and QoL did not vary with age.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3395-z) contains supplementary material, which is available to authorized users.

Cost-effectiveness of the recombinant zoster vaccine in the German population aged ≥60 years old

Each year, around 300,000 Herpes Zoster (HZ) cases are observed in the German population, resulting in costs over €182 million to society. The objective of this study was to estimate the potential public health and economic impact of the new Adjuvanted Recombinant Zoster Vaccine (RZV, Shingrix) in the German population ≥ 60 years of age (YOA) and to identify the optimal age of vaccination. We used a static, multi-cohort Markov model that followed a hypothetical cohort of 1 million people ≥ 60 YOA life-long after vaccination using German-specific inputs. Both costs and outcomes were discounted at 3%, the incremental cost-effectiveness ratio (ICER) was calculated based on the societal perspective. The coverage of RZV was set at 40% with a second-dose compliance of 70%. Vaccinating the population aged ≥ 60 YOA would result in 45,000 HZ cases avoided, 1,713 quality-adjusted life years (QALYs) gained at a total cost of approximately €63 million compared to 38,000 cases avoided, 1,545 QALYs gained at a total cost of approximately €68 million in the population ≥ 70 YOA. This would result in an ICER of approximately €37,000 and €44,000/QALY, for the age cohort ≥ 60 and ≥ 70 YOA, respectively. Scenario analyses demonstrated that vaccinating at age 60 or 65 YOA would show greater public health impact and would result in the lowest observed ICER compared to vaccinating at 70 YOA. In conclusion, starting vaccination with RZV in the German population ≥ 60 YOA would demonstrate the best value from a public health and economic standpoint.

Sponsorship Bias in Base-Case Values and Uncertainty Bounds of Health Economic Evaluations? A Systematic Review of Herpes Zoster Vaccination

BACKGROUND

New health technologies are more likely adopted when they have lower incremental cost-effectiveness ratios (ICERs) and/or when their ICER is presented with more certainty. Industry-funded (IF) health economic evaluations use often more favorable base-case values, leading to more favorable conclusions.

PURPOSE

To study whether IF health economic evaluations of varicella-zoster virus vaccination in the elderly use more favorable base-case values and account for less uncertainty than non-industry-funded (NIF) evaluations.

METHODS

DATA SOURCE

PubMed. Data extracted: funding source; incremental cost per quality-adjusted life year (QALY) gained; vaccine price; study quality score; base-case values, uncertainty ranges, and data sources for influential parameters: duration of vaccine protection, utility loss due to herpes zoster (HZ) disease, percentage of HZ patients developing postherpetic neuralgia (PHN), and duration of PHN.

DATA SYNTHESIS

qualitative comparisons; Fisher exact test for differences in study quality score and 1-sided Mann-Whitney U tests for differences in base-case values and uncertainty ranges.

RESULTS

Despite using the same data sources, IF studies ( n = 10) assume a longer duration of vaccine protection ( U = 56, P = 0.03), have a higher percentage of HZ patients developing PHN ( U = 22/33, P = 0.02/0.03 for ages 60-64/65-69), and tend to use higher HZ utility loss than NIF studies ( n = 11) for their baseline. IF studies show lower ICERs given similar or even higher vaccine prices than NIF studies, consider less uncertainty around the duration of vaccine protection ( U = 8, P < 0.001), and tend to use less uncertainty around the duration of PHN. Yet their quality has been rated equally well, using current standard quality rating tools.

CONCLUSION

Researchers and decision makers should be aware of potential sponsorship bias in health economic evaluations, especially in the way source data are used to specify base-case values and uncertainty ranges.

The Potential Public Health Impact of Herpes Zoster Vaccination of People Aged ≥ 50 Years in Japan: Results of a Markov Model Analysis

INTRODUCTION

The aim of this study was to compare the public health impact of introducing two herpes zoster (HZ) vaccines into the vaccination programs for the Japanese population aged ≥ 50 years: a single-dose Varicella Vaccine Live (VVL) or a two-dose adjuvanted Recombinant Zoster Vaccine (RZV).

METHODS

A multi-cohort static Markov model was developed to follow age cohorts (50-59, 60-69, 70-79 and ≥ 80 years) over their remaining lifetime. Japan-specific data inputs for the model were obtained from Japanese data sources. Age-stratified vaccine efficacy and waning rates were based on published clinical trial data. In the base-case analysis, vaccine coverage was assumed to be 40% for both vaccines, and compliance with second-dose of the RZV vaccine was set to 95%.

RESULTS

Vaccination with RZV was projected to prevent approximately 3.3 million HZ cases, 692,000 cases of postherpetic neuralgia (PHN), and 281,000 cases of other complications, compared with the prevention of 0.8 million HZ cases, 216,000 PHN cases, and 57,000 other complications with vaccination with VVL. The number of individuals needed to vaccinate in order to prevent one HZ case ranged from 6 to 14 using RZV (depending on age and assumed second-dose compliance) and from 21 to 138 depending on age using VVL. By preventing a higher number of HZ cases and its complications, RZV vaccination led to fewer outpatient visits and hospitalizations than vaccination with VVL.

CONCLUSION

Both vaccines had a positive public health impact compared to no vaccination, but due to its higher vaccine efficacy, RZV demonstrated a superior public health impact compared with VVL.

FUNDING

GlaxoSmithKline Biologicals SA.

Cost Effectiveness of a Shingles Vaccine Booster for Currently Vaccinated Adults in the U.S

INTRODUCTION

The Advisory Committee on Immunization Practices recommends a single dose of the live attenuated herpes zoster vaccine in people aged ≥60 years. Because vaccine-induced protection decreases to zero after 10 years, many vaccinated people will soon be subject to an increased risk of the disease. The study objective was to determine the cost effectiveness of a herpes zoster vaccine booster and its optimal timing among immunocompetent adults first vaccinated at aged ≥60 years.

METHODS

A Markov model was built to follow vaccinated individuals for a lifetime. From the societal perspective, costs and quality-adjusted life years were compared between no booster versus booster options. A booster was given any time between 1 and 20 years after the first dose, and for those who had the first dose at different ages: 60, 70, and 80 years. Because people entered the model already vaccinated, costs and side effects of the first dose were not included. The booster was assumed to have the same efficacy and waning rate as the initial vaccination. Model inputs were based on published literature. A cost effectiveness threshold of $100,000/quality-adjusted life year was used. The analysis was conducted in 2016.

RESULTS

Cost effectiveness of a booster varied by age and time since vaccination. The booster cost <$100,000/quality-adjusted life year if given >5 years after the initial dose, but was most cost effective at around 10 years. The finding was robust to wide variations in model inputs.

CONCLUSIONS

Under current assumptions, a booster dose of herpes zoster vaccine would be cost effective for all vaccinated people 10 years after initial vaccination.

Assessment of the potential public health impact of Herpes Zoster vaccination in Germany

The aim of this study was to compare the public health impact of introducing 2 Herpes Zoster (HZ) vaccines, Zoster Vaccine Live (ZVL) versus a non-live adjuvanted subunit candidate vaccine (HZ/su), in the German population aged 50+ years split into 3 age cohorts, i.e. 50–59, 60–69 and 70+ years, respectively. A multi-cohort static Markov model was developed following age cohorts over their lifetime. Demographic data were obtained from the German federal statistical office. HZ incidence and the proportion of HZ individuals developing post-herpetic neuralgia (PHN) were derived from German specific sources. Age-specific vaccine efficacy and waning rates were based on published clinical trial data. Vaccine coverage for both vaccines was assumed to be 40%, with compliance of the second dose of the HZ/su vaccine of 70%. Sensitivity analyses were performed to assess the robustness of the results. It was estimated that, over the remaining lifetime since vaccination, the HZ/su vaccine would reduce the number of HZ cases by 725,233, 533,162 and 486,794 in the 3 age cohorts, respectively, compared with 198,477, 196,000 and 104,640, using ZVL. The number needed to vaccinate (NNV) to prevent one HZ case ranged from 8 to 11 using the HZ/su vaccine compared with 20 to 50 using ZVL. Corresponding NNV to prevent one PHN case ranged from 39 to 53 using the HZ/su vaccine compared with 94 to 198 using ZVL. Due to the higher, sustained vaccine efficacy, the candidate HZ/su vaccine demonstrated superior public health impact compared with ZVL.

Cost-effectiveness of 13-valent pneumococcal conjugate vaccine (PCV13) in older Australians

BACKGROUND

The 23-valent pneumococcal polysaccharide vaccine (PPV23) has been funded under the Australia National Immunisation Program (NIP) since January 2005 for those aged >65years and other risk groups. In 2016, PCV13 was accepted by the Pharmaceutical Benefits Advisory Committee (PBAC) as a replacement for a single dose of PPV23 in older Australian adults.

METHODS

A single-cohort deterministic multi-compartment (Markov) model was developed describing the transition of the population between different invasive and non-invasive pneumococcal disease related health states. We applied a healthcare system perspective with costs (Australian dollars, A$) and health effects (measured in quality adjusted life-years, QALYs) attached to model states and discounted at 5% annually. We explored replacement of PPV23 with PCV13 at 65years as well as other age based vaccination strategies. Parameter uncertainty was explored using deterministic and probabilistic sensitivity analysis.

RESULTS

In a single cohort, we estimated PCV13 vaccination at the age of 65years to cost ∼A$11,120,000 and prevent 39 hospitalisations and 6 deaths from invasive pneumococcal disease and 180 hospitalisations and 10 deaths from community acquired pneumonia. The PCV13 program had an incremental cost-effectiveness ratio of ∼A$88,100 per QALY gained when compared to a no-vaccination, whereas PPV23 was ∼A$297,200 per QALY gained. To fall under a cost-effectiveness threshold of A$60,000 per QALY, PCV13 would have to be priced below ∼A$46 per dose. The cost-effectiveness of PCV13 in comparison to PPV23 was ∼A$35,300 per QALY gained.

CONCLUSION

In comparison to no-vaccination, we found PCV13 use in those aged 65years was unlikely to be cost-effective unless the vaccine price was below A$46 or a longer duration of protection can be established. However, we found that in comparison to the PPV23, vaccination with PCV13 was cost-effective. This partly reflects the poor value for money estimated for PPV23 use in Australia.

Determining the Optimal Vaccination Schedule for Herpes Zoster: a Cost-Effectiveness Analysis

BACKGROUND

The Advisory Committee on Immunization Practices recommends a single dose of herpes zoster (HZ) vaccine in persons aged 60 years or older, but the efficacy decreases to zero after approximately 10 years. A booster dose administered after 10 years might extend protection, but the cost-effectiveness of a booster strategy has not been examined.

OBJECTIVE

We aimed to determine the optimal schedule for HZ vaccine DESIGN: We built a Markov model to follow patients over their lifetime. From the societal perspective, we compared costs and quality-adjusted life years (QALYs) saved of 11 strategies to start and repeat HZ vaccine at different ages.

SUBJECTS

Adults aged 60 years.

INTERVENTION

HZ vaccine.

MAIN MEASURES

Costs, quality-adjusted life years (QALYs), and incremental costs per QALY saved.

KEY RESULTS

At a $100,000/QALY threshold, "vaccination at 70 plus one booster" was the most cost-effective strategy, with an incremental cost-effectiveness ratio (ICER) of $36,648/QALY. "Vaccination at 60 plus two boosters" was more effective, but had an ICER of $153,734/QALY. In deterministic sensitivity analysis, "vaccination at 60 plus two boosters" cost < $100,000/QALY if compliance rate was > 67 % or vaccine cost was < $156 per dose. In probabilistic sensitivity analysis, "vaccination at 70 plus one booster" was preferred at a willingness-to-pay of up to $135,000/QALY.

CONCLUSIONS

Under current assumptions, initiating HZ vaccine at age 70 years with one booster dose 10 years later appears optimal. Future data regarding compliance with or efficacy of a booster could affect these conclusions.

Shingles (Herpes Zoster) Vaccine (Zostavax(®)): A Review in the Prevention of Herpes Zoster and Postherpetic Neuralgia

Zostavax(®) is a live attenuated shingles (herpes zoster) vaccine approved in the EU for the prevention of herpes zoster (HZ) and postherpetic neuralgia (PHN) in adults aged ≥50 years. Zoster vaccine protected against HZ in adults aged 50-59 years (ZEST trial) and ≥60 years [Shingles Prevention Study (SPS)], and also reduced the burden of illness associated with HZ and the risk of PHN in adults aged ≥60 years (SPS). A large amount of real-world data also supports the efficacy of zoster vaccine. Results of the SPS Short- and Long-Term Persistence Substudies and real-world studies indicate that zoster vaccine provided continued benefit in the longer term, albeit with a gradual decline in vaccine efficacy over time; long-term effectiveness studies are ongoing. The need for a booster dose is still unknown, but a study showed that, if necessary, a booster dose administered to adults aged ≥70 years who received their first dose of zoster vaccine ≥10 years previously was immunogenic. Zoster vaccine had a favourable safety and tolerability profile, with the most commonly reported adverse events being non-severe injection-site reactions. In conclusion, zoster vaccine reduces the incidence of HZ and PHN, thereby reducing the burden of illness associated with HZ; improved uptake of zoster vaccine is needed.

Clinical and economic impact of herpes zoster vaccination in elderly in Italy

Herpes zoster (HZ) is a very relevant pathology among elderly people (≥ 60 years of age), with a considerable disease burden and loss of quality of life. In the last years a new vaccine against HZ became available in Italy. Therefore, the Italian decision makers are now confronted with the decision whether that vaccination should be implemented. Pharmaco-economic analyses represent useful tools to value the feasibility of new immunization programs and their sustainability. To this aim, an ad hoc population model was developed in order to value the clinical and economic impact of HZ vaccination program for the elderly in Italy. Particularly, different immunization scenarios were modeled: vaccination of 60 years-old subjects (single cohort strategy), simultaneous vaccination of people aged 60 and 65 years (double cohort strategy) and, lastly, immunization of people aged 60, 65 and 70 years (triple cohort strategy), thus leading to the vaccination of 5, 10 and 15 cohorts during the first 5 years of the program. The mathematical model valued the clinical impact of vaccination on the number of HZ, post-herpetic neuralgia (PHN) and ophthalmic HZ. The results of the analysis show that, in Italy, a cohort-based HZ vaccination program in elderly could have a relevant impact on the reduction of clinical cases and a favorable economic profile for the National Health Service (NHS), as already foreseen in other countries. In addition, further benefits could be obtained when extending the study period beyond the 5-year horizon of our analysis.

Economic Evaluation of Vaccination Programmes in Older Adults and the Elderly: Important Issues and Challenges

High-income countries are undergoing demographic transitions towards populations with substantial larger proportions of older adults. Due to the increased susceptibility of older adults to infectious diseases and their consequences, vaccination programmes are an important health intervention to help maintain healthy ageing. While much of the existing literature suggests that current vaccination programmes targeted at older adults and the elderly are likely to be cost effective in high-income countries, we argue that it is important to more fully consider some important issues and challenges. Since the majority of vaccines have been developed for children, economic evaluations of vaccination programmes have consequentially tended to focus on this age group and on how to incorporate herd-immunity effects. While programmes targeted at older adults and the elderly may also induce some herd effects, there are other important challenges to consider in these economic evaluations. For example, age and time effects in relation to vaccine efficacy and duration of immunity, as well as heterogeneity between targeted individuals in terms of risk of infection, severity of disease and response to vaccination. For some pathogens, there is also the potential for interactions with childhood programmes in the form of herd-immunity effects.

The use of Zostavax in Spain: the economic case for vaccination of individuals aged 50 years and older

Background Population aging brings up a number of health issues, one of which is an increased incidence of herpes zoster (HZ) and its complication, post-herpetic neuralgia (PHN). Zostavax vaccine has recently become available to prevent HZ and PHN. This study evaluates the cost-effectiveness of vaccination against HZ in Spain considering a vaccination of the population aged 50 years and older and comparing this to the current situation where no vaccination is being administered. Methods An existing, validated, and published economic model was adapted to Spain using relevant local input parameters and costs from 2013. Results Vaccinating 30% of the Spanish population aged 50 years and older resulted in €16,577/QALY gained, €2025/HZ case avoided, and €5594/PHN case avoided under the third-party payer perspective. From a societal perspective, the ICERs increased by 6%, due to the higher price of the vaccine. The number needed to vaccinate to prevent one case was 20 for HZ, and 63 for PHN3. Sensitivity analyses showed that the model was most sensitive to the HZ and PHN epidemiological data, the health state utilities values, and vaccine price used. Conclusion Considering an acceptable range of cost-effectiveness of €30,000-€50,000 per QALY gained, vaccination of the 50+ population in Spain against HZ with a new vaccine, Zostavax, is cost-effective and makes good use of the valuable healthcare budget.

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.

Cost-effectiveness analysis of a vaccination program for the prevention of herpes zoster and post-herpetic neuralgia in adults aged 50 and over in Germany

Herpes zoster (HZ; shingles) is a common viral disease that affects the nerves and surrounding skin causing a painful dermatomal rash and leading to debilitating complications such as, mainly, post-herpetic neuralgia (PHN). Currently, there is no effective treatment for HZ and PHN. The objective of this study was to assess the cost-effectiveness of a HZ vaccination program in Germany. An existing Markov Model was adapted to the German healthcare setting to compare a vaccination policy to no vaccination on a lifetime time-horizon, considering 2 scenarios: vaccinating people starting at the age of 50 or at the age of 60 years, from the perspective of the statutory health insurance (SHI) and the societal perspective. According to the perspective, vaccinating 20% of the 60+ German population resulted in 162,713 to 186,732 HZ and 31,657 to 35,793 PHN cases avoided. Corresponding incremental cost-effectiveness ratios (ICER) were 39,306 €/QALY from the SHI perspective and 37,417 €/QALY from a societal perspective. Results for the 50+ German population ranged from 336,468 to 394,575 HZ and from 48,637 to 56,087 PHN cases avoided from the societal perspective. Corresponding ICER were 39,782 €/QALY from a SHI perspective and 32,848 €/QALY from a societal perspective. Sensitivity analyses showed that results are mainly impacted by discount rates, utility values and use of alternative epidemiological data.The model indicated that a HZ vaccination policy in Germany leads to significant public health benefits and could be a cost-effective intervention. The results were robust and consistent with local and international existing literature.

Current and future effects of varicella and herpes zoster vaccination in Germany - Insights from a mathematical model in a country with universal varicella vaccination

Varicella zoster virus (VZV) is primarily known for causing varicella in childhood, but can reactivate again as herpes zoster (HZ) after a period of latency, mainly in persons older than 50 years. Universal varicella vaccination was introduced in Germany in 2004, while HZ vaccination has not been recommended yet. We aimed to quantify the potential long-term effects of universal childhood varicella vaccination and HZ vaccination of the elderly on varicella and HZ incidence in Germany over a time horizon of 100 years, using a transmission model calibrated to pre-vaccination data and validated against early post-vaccination data. Using current vaccination coverage rates of 87% (64%) with one (two) varicella vaccine dose(s), the model predicts a decrease in varicella cases by 89% for the year 2015. In the long run, the incidence reduction will stabilize at about 70%. Under the assumption of the boosting hypothesis of improved HZ protection caused by exposure to VZV, the model predicts a temporary increase in HZ incidence of up to 20% for around 50 years. HZ vaccination of the elderly with an assumed coverage of 20% has only limited effects in counteracting this temporary increase in HZ incidence. However, HZ incidence is shown to decrease in the long-term by 58% as vaccinated individuals get older and finally reach age-classes with originally high HZ incidence. Despite substantial uncertainties around several key variables, the model's results provide valuable insights that support decision-making regarding national VZV vaccination strategies.

[Vaccines against Herpes zoster: Effectiveness, safety, and cost/benefit ratio]

CONTEXT

A vaccination against herpes zoster and its complication is available in France since June 2015. Its exact benefit for public health is still controversial and its level of protection is not optimal. All those reasons seem to suggest a low acceptation rate from general practitioners.

OBJECTIVE

To evaluate the effectiveness, the safety, and the cost/benefit ratio of the vaccination against herpes zoster in people aged 50 year or over.

DOCUMENTARY SOURCE

Systematic review in Medline and PubMed with research by key words: "herpes zoster vaccine", "zoster vaccine" and "post herpetic neuralgia vaccine".

SELECTION OF STUDIES

Randomized and observational studies published in English and French language have been selected by two readers.

RESULTS

On 1886 articles identified, 62 studies were included in this systematic review of which 21 randomized trials, 21 observational studies, and 17 medico-economic studies concerned the unadjuvanted vaccine. Considered studies showed an effectiveness of 50% against herpes zoster and 60% on post-herpetic neuralgia incidence of the unadjuvanted vaccine. Five randomized controlled studies were identified for the adjuvanted vaccine. The overall effectiveness of this vaccine was > 90% whatever the age of subjects including those over age 70 and 80. The medico-economic studies conducted in many countries have shown that vaccine policies were beneficial in individuals aged 60 years or over.

LIMITATION OF THE WORK

Most of data of effectiveness, and tolerance result from 2 large controlled studies only (SPS and ZEST) for the unadjuvanted vaccine and only one for the adjuvanted vaccine.

CONCLUSION

Despite controversy and few uncertainties, the vaccine significantly reduces herpes zoster and its complication incidence. In terms of public health objectives, it reduces the burden of the disease and has a positive medico-economic impact. Preliminary data concerning the adjuvanted vaccine, whilst very promising, are still too limited. Up to now, no group of people with particularly high risk of herpes zoster-related complication who will beneficiate the most of the vaccination has been identified yet and only an age criteria has been considered for the recommendation.

Cost-Effectiveness of Herpes Zoster Vaccine for Persons Aged 50 Years

BACKGROUND

Each year, herpes zoster (HZ) affects 1 million U.S. adults, many of whom develop postherpetic neuralgia (PHN). Zoster vaccine is licensed for persons aged 50 years or older, but its cost-effectiveness for those aged 50 to 59 years is unknown.

OBJECTIVE

To estimate the cost-effectiveness of HZ vaccine versus no vaccination.

DESIGN

Markov model.

DATA SOURCES

Medical literature.

TARGET POPULATION

Adults aged 50 years.

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal.

INTERVENTION

HZ vaccine.

OUTCOME MEASURES

Number of HZ and PHN cases prevented and incremental cost per quality-adjusted life-year (QALY) saved.

RESULTS OF BASE-CASE ANALYSIS

For every 1000 persons receiving the vaccine at age 50 years, 25 HZ cases and 1 PHN case could be prevented. The incremental cost-effectiveness ratio (ICER) for HZ vaccine versus no vaccine was $323 456 per QALY.

RESULTS OF SENSITIVITY ANALYSIS

In deterministic and scenario sensitivity analyses, the only variables that produced an ICER less than $100 000 per QALY were vaccine cost (at a value of $80) and the rate at which efficacy wanes. In probabilistic sensitivity analysis, the mean ICER was $500 754 per QALY (95% CI, $93 510 to $1 691 211 per QALY). At a willingness-to-pay threshold of $100 000 per QALY, the probability that vaccination would be cost-effective was 3%.

LIMITATION

Long-term effectiveness data for HZ vaccine are lacking for 50-year-old adults.

CONCLUSION

Herpes zoster vaccine for persons aged 50 years does not seem to represent good value according to generally accepted standards. Our findings support the decision of the Advisory Committee on Immunization Practices not to recommend the vaccine for adults in this age group.

PRIMARY FUNDING SOURCE

None.

Herpes zoster epidemiology, management, and disease and economic burden in Europe: a multidisciplinary perspective

Herpes zoster (HZ) is primarily a disease of nerve tissue but the acute and longer-term manifestations require multidisciplinary knowledge and involvement in their management. Complications may be dermatological (e.g. secondary bacterial infection), neurological (e.g. long-term pain, segmental paresis, stroke), ophthalmological (e.g. keratitis, iridocyclitis, secondary glaucoma) or visceral (e.g. pneumonia, hepatitis). The age-related increased incidence of HZ and its complications is thought to be a result of the decline in cell-mediated immunity (immunosenescence), higher incidence of comorbidities with age and social-environmental changes. Individuals who are immunocompromised as a result of disease or therapy are also at increased risk, independent of age. HZ and its complications (particularly postherpetic neuralgia) create a significant burden for the patient, carers, healthcare systems and employers. Prevention and treatment of HZ complications remain a therapeutic challenge despite recent advances. This is an overview of the multidisciplinary implications and management of HZ in which the potential contribution of vaccination to reducing the incidence HZ and its complications are also discussed.

Systematic review of models assessing the economic value of routine varicella and herpes zoster vaccination in high-income countries

BACKGROUND

A systematic review was conducted to assess the cost-effectiveness of routine varicella and herpes zoster (HZ) vaccination in high-income countries estimated by modelling studies.

METHODS

A PubMed search was performed to identify relevant studies published before October 2013. Studies were included in the review if they (i) evaluated the cost-effectiveness of routine childhood or adolescent varicella vaccination and/or HZ vaccination targeting the elderly, and if they (ii) reported results for high-income countries.

RESULTS

A total of 38 model-based studies were identified that fulfilled the inclusion criteria. Routine childhood or adolescent varicella vaccination was cost-effective or cost-saving from a payer perspective and always cost-saving from a societal perspective when ignoring its potential impact on HZ incidence due to reduced or absent exogenous boosting. The inclusion of the potential impact of childhood varicella vaccination on HZ led to net quality-adjusted life-year (QALY) losses or incremental cost-effectiveness ratios exceeding commonly accepted thresholds. Additional HZ vaccination could partially mitigate this effect. Studies focusing only on the evaluation of HZ vaccination reported a wide range of results depending on the selected target age-group and the vaccine price, but most found HZ vaccination to be a cost-effective or marginally cost-effective intervention. Cost-effectiveness of HZ vaccination was strongly dependent on the age at vaccination, the price of the vaccine, the assumed duration of protection and the applied cost per QALY threshold.

CONCLUSIONS

While HZ vaccination is mostly considered cost-effective, cost-effectiveness of varicella vaccination primarily depends on the in- or exclusion of exogenous boosting in the model. As a consequence, clarification on the role of exogenous boosting is crucial for decision-making regarding varicella vaccination.

The burden of disease of Herpes Zoster in Tuscany

Herpes zoster (HZ) is a disease caused by the reactivation of the latent α-herpes virus varicella zoster virus (VZV), for which, in Italy, a specific surveillance system does not exist, but around 200 000 cases are estimated each year. In older patients, who are at increased risk of developing HZ, symptoms are more severe and the chances to develop postherpetic neuralgia (PHN), the most severe complication, are substantially higher. A vaccine against HZ with demonstrated efficacy and an acceptable safety profile is now available and is recommended in Europe for adults >50 years.   In anticipation of the possible introduction of an immunization programme for the elderly in Tuscany, the burden of disease caused by HZ and its complications was assessed through a retrospective analysis of the hospital discharge records between 2002 and 2012, using the ICD-9-CM 053 code. In the period 2002-2012, 4475 hospital admissions were registered with annual means of 368 hospitalizations and 39 day-hospital admissions. Most of the hospitalizations (68%) involved subjects > 65 years; the mean length of stay was 9.5 days. Slightly more than half (51.2%) of total hospital admissions were complicated cases. The most frequent were neurological complications (24.2% of total admissions), followed by ophthalmic complications (16.5%). Cases with neurological complications were those with the higher average length of stay and higher average costs for case. This study confirmed the epidemiological impact of HZ and its complications and the positive impact on morbidity that the introduction of the HZ vaccination could have in older age groups.

Cost-effectiveness of vaccination against herpes zoster and postherpetic neuralgia: a critical review

OBJECTIVE

The objective of this study was to systematically review cost-effectiveness studies of vaccination against herpes zoster (HZ) and postherpetic neuralgia (PHN).

METHODS

We searched MEDLINE and EMBASE databases for eligible studies published prior to November 2013. We extracted information regarding model structure, model input parameters, and study results. We compared the results across studies by projecting the health and economic impacts of vaccinating one million adults over their lifetimes.

RESULTS

We identified 15 cost-effectiveness studies performed in North America and Europe. Results ranged from approximately US$10,000 to more than US$100,000 per quality-adjusted life years (QALY) gained. Most studies in Europe concluded that zoster vaccination is likely to be cost-effective. Differences in results among studies are largely due to differing assumptions regarding duration of vaccine protection and a loss in quality of life associated with HZ and to a larger extent, PHN. Moreover, vaccine efficacy against PHN, age at vaccination, and vaccine cost strongly influenced the results in sensitivity analyses.

CONCLUSION

Most studies included in this review shows that vaccination against HZ is likely to be cost-effective. Future research addressing key model parameters and cost-effectiveness studies in other parts of the world are needed.