Cost-effectiveness of the adjuvanted quadrivalent influenza vaccine for older adults in South Korea

South Korea's National Immunization Program administers the quadrivalent influenza vaccine (QIV) to manage seasonal influenza, with a particular focus on the elderly. After reviewing the safety and immune response triggered by the adjuvanted QIV (aQIV) in individuals aged 65 and older, the Ministry of Food and Drug Safety in Korea approved its use. However, the extensive impact of aQIV on public health is yet to be fully understood. This study assessed the cost-effectiveness of replacing QIV with aQIV in South Korean adults aged 65 years and older. A dynamic transmission model, calibrated with national influenza data, was applied to compare the influence of aQIV and QIV on older adults and the broader population throughout a single influenza season. This study considered both the direct and indirect effects of vaccination on the elderly. We derived the incremental cost-effectiveness ratios (ICERs) from quality-adjusted life-years (QALYs) and costs incurred, validated through a probabilistic sensitivity analysis with 5,000 simulations. Findings suggest that transitioning to aQIV from QIV in the elderly would be cost-effective, particularly if aQIV's efficacy reaches or exceeds 56.1%. With an ICER of $29,267/QALY, considerably lower than the $34,998/QALY willingness-to-pay threshold, aQIV presents as a cost-effective option. Thus, implementing aQIV with at least 56.1% efficacy is beneficial from both financial and public health perspectives in mitigating seasonal influenza in South Korea.

Cost-effectiveness of high-dose influenza vaccination in the Netherlands: Incorporating the impact on both respiratory and cardiovascular hospitalizations

OBJECTIVES

We assess the cost-effectiveness of switching from standard-dose quadrivalent influenza vaccination (SD-QIV) to high-dose vaccination (HD-QIV) for Dutch adults aged 60 years and older.

METHODS

A health-economic model was used to compare the scenario where HD-QIV was implemented compared to the current standard, SD-QIV. This model used a lifetime horizon and assessed the cost-effectiveness from a societal perspective. A recently published meta-analysis was used to incorporate the benefits of HD-QIV, including cardiorespiratory hospitalizations, in analyses considering RCT only or combining RCT and RWE estimates in a scenario analysis.

RESULTS

Implementing HD-QIV is cost effective at its list price, with an ICER of €5,400 per QALY gained. The main driver of these results is the prevention of cardiorespiratory hospitalizations. Other public health benefits are the prevention of GP consults and deaths. HD-QIV is highly likely to be cost-effective, reaching a 100% probability of being cost effective at the Dutch willingness-to-pay threshold of €20,000 per QALY.

CONCLUSIONS

Implementing HD-QIV for adults aged 60 and over within the existing influenza vaccination campaign is highly cost effective. HD-QIV may support alleviating potential capacity issues in Dutch hospitals in the winter respiratory season.

Public health and economic benefits of seasonal influenza vaccination in risk groups in France, Italy, Spain and the UK: state of play and perspectives

BACKGROUND

Seasonal influenza epidemics have a substantial public health and economic burden, which can be alleviated through vaccination. The World Health Organization (WHO) recommends a 75% vaccination coverage rate (VCR) in: older adults (aged ≥ 65 years), individuals with chronic conditions, pregnant women, children aged 6-24 months and healthcare workers. However, no European country achieves this target in all risk groups. In this study, potential public health and economic benefits achieved by reaching 75% influenza VCR was estimated in risk groups across four European countries: France, Italy, Spain, and the UK.

METHODS

A static epidemiological model was used to estimate the averted public health and economic burden of increasing the 2021/2022 season VCR to 75%, using the efficacy data of standard-dose quadrivalent influenza vaccine. For each country and risk group, the most recent data on population size, VCR, pre-pandemic influenza epidemiology, direct medical costs and absenteeism were identified through a systematic literature review, supplemented by manual searching. Outcomes were: averted influenza cases, general practitioner (GP) visits, hospitalisations, case fatalities, number of days of work lost, direct medical costs and absenteeism-related costs.

RESULTS

As of the 2021/2022 season, the UK achieved the highest weighted VCR across risk groups (65%), followed by Spain (47%), France (44%) and Italy (44%). Based on modelling, the 2021/2022 VCR prevented an estimated 1.9 million influenza cases, avoiding 375,200 GP visits, 73,200 hospitalisations and 38,400 deaths. To achieve the WHO 75% VCR target, an additional 24 million at-risk individuals would need to be vaccinated, most of which being older adults and patients with chronic conditions. It was estimated that this could avoid a further 918,200 influenza cases, 332,000 GP visits, 16,300 hospitalisations and 6,300 deaths across the four countries, with older adults accounting for 52% of hospitalisations and 80% of deaths. An additional €84 million in direct medical costs and €79 million in absenteeism costs would be saved in total, with most economic benefits delivered in France.

CONCLUSIONS

Older adults represent most vaccine-preventable influenza cases and deaths, followed by individuals with chronic conditions. Health authorities should prioritise vaccinating these populations for maximum public health and economic benefits.

Cost-effectiveness of seasonal influenza vaccination of children in China: a modeling analysis

BACKGROUND

China has a high burden of influenza-associated illness among children. We aimed to evaluate the cost-effectiveness of introducing government-funded influenza vaccination to children in China (fully-funded policy) compared with the status quo (self-paid policy).

METHODS

A decision tree model was developed to calculate the economic and health outcomes, from a societal perspective, using national- and provincial-level data. The incremental cost-effectiveness ratio (ICER) [incremental costs per quality-adjusted life year (QALY) gained] was used to compare the fully-funded policy with the self-paid policy under the willingness-to-pay threshold equivalent to national and provincial GDP per capita. Sensitivity analyses were performed and various scenarios were explored based on real-world conditions, including incorporating indirect effect into the analysis.

RESULTS

Compared to the self-paid policy, implementation of a fully-funded policy could prevent 1,444,768 [95% uncertainty range (UR): 1,203,446-1,719,761] symptomatic cases, 92,110 (95% UR: 66,953-122,226) influenza-related hospitalizations, and 6494 (95% UR: 4590-8962) influenza-related death per season. The fully-funded policy was cost-effective nationally (7964 USD per QALY gained) and provincially for 13 of 31 provincial-level administrative divisions (PLADs). The probability of a funded vaccination policy being cost-effective was 56.5% nationally, and the probability in 9 of 31 PLADs was above 75%. The result was most sensitive to the symptomatic influenza rate among children under 5 years [ICER ranging from - 25,612 (cost-saving) to 14,532 USD per QALY gained]. The ICER of the fully-funded policy was substantially lower (becoming cost-saving) if the indirect effects of vaccination were considered.

CONCLUSIONS

Introducing a government-funded influenza policy for children is cost-effective in China nationally and in many PLADs. PLADs with high symptomatic influenza rate and influenza-associated mortality would benefit the most from a government-funded influenza vaccination program.

Correspondence to: Estimating the full health and economic benefits of current and future influenza vaccines

We recently published an article in BMC Medicine looking at the potential health and economic impact of paediatric vaccination using next-generation influenza vaccines in Kenya: a modelling study. In their commentary on our article, Lafond et al. highlight the potential importance of the wider benefits of vaccination on cost-effectiveness. Whilst we agree with many points raised in the commentary, we think it raises further interesting discussion points, specifically around model complexity, model assumptions and data availability. These points are both relevant to this manuscript but have wider implications for vaccine cost-effectiveness studies.

Estimating the full health and economic benefits of current and future influenza vaccines

In the dynamic landscape of respiratory virus vaccines, it is crucial to assess the value of novel mRNA and combination influenza/COVID-19 vaccines in low- and middle-income countries. Modeling studies, such as the one conducted by Waterlow et al., provide vital information about the cost-benefit potential of these products compared to currently licensed vaccines. However, this approach only accounts for directly measured medically attended influenza-associated illnesses and has two major limitations. First, this method fails to capture the full disease burden of influenza (including non-respiratory and non-medically attended influenza illnesses), which are particularly important drivers of disease burden in infants and older adults. Second, the model does not describe the ancillary benefits of influenza vaccination such as the attenuation of severe disease, prevention of severe non-respiratory outcomes (e.g., myocardial infarctions), or reduced antibiotic use. To obtain a comprehensive understanding of the benefits of influenza vaccines, we must strive to improve the inputs for future modeling-based evaluations.

Investigating the procurement system for understanding seasonal influenza vaccine brand availability in Europe

Background

Timely knowledge of which influenza vaccine brands are procured and where is of interest to inform site-selection for brand-specific influenza vaccine effectiveness (VE) studies. Vaccine procurement is a key determinant of brand availability. We therefore sought to understand how the procurement for seasonal influenza vaccine in Europe is organized, how this drives brand availability and how procurement data could enable to determine brand availability pre-season.

Methods

Structured telephone interviews were conducted with 15 experts in 16 European countries between 2017 and 2019 to collect information on the influenza vaccine procurement systems. Sources of (brand-specific) procurement data were identified and assessed on public accessibility. Vaccine type and brand availability and timelines were determined for the 2019–20 season to understand how procurement systems drive brand availability and diversity.

Results

Four main types of procurement systems for seasonal influenza vaccination campaigns were identified: national public tenders (Croatia, Denmark, Finland, Ireland, Lithuania, Netherlands, Norway, Scotland, Slovenia), regional public tenders (Italy, Spain, Sweden), direct purchase of vaccines by GPs (England, Wales) or pharmacies (Belgium, France, Germany, Greece) from manufacturers or wholesalers. National public tender outcomes are publicly available and timely; brand availability at clinic level can generally be deduced or narrowed down to two brands. Regional tender outcomes are more difficult to find, known very late or not available. In Italian and Spanish regions tenders may be awarded only a few weeks before the seasonal campaign. No public procurement information is available for countries with direct purchase.

Conclusion

At the country-level, brand diversity is generally lower for countries with national public tenders than for countries with regional public tenders or direct purchase. In only a few countries, procurement data at the brand level is both publicly available and timely. Therefore the usefulness of procurement data for prospective site-selection for brand-specific VE studies is limited.

Priority allocation of pandemic influenza vaccines in Australia - Recommendations of 3 community juries

BACKGROUND

Pandemic planning has historically been oriented to respond to an influenza virus, with vaccination strategy being a key focus. As the current COVID-19 pandemic plays out, the Australian government is closely monitoring progress towards development of SARS-CoV2 vaccines as a definitive intervention. However, as in any pandemic, initial supply will likely be exceeded by demand due to limited manufacturing output.

METHODS

We convened community juries in three Australian locations in 2019 to assess public acceptability and perceived legitimacy of influenza pandemic vaccination distribution strategies. Preparatory work included literature reviews on pandemic vaccine allocation strategies and on vaccine allocation ethics, and simulation modelling studies. We assumed vaccine would be provided to predefined priority groups. Jurors were then asked to recommend one of two strategies for distributing remaining early doses of vaccine: directly vaccinate people at higher risk of adverse outcomes from influenza; or indirectly protect the general population by vaccinating primary school students, who are most likely to spread infection.

RESULTS

Thirty-four participants of diverse backgrounds and ages were recruited through random digit dialling and topic-blinded social media advertising. Juries heard evidence and arguments supporting different vaccine distribution strategies, and questioned expert presenters. All three community juries supported prioritising school children for influenza vaccination (aiming for indirect protection), one by 10-2 majority and two by consensus. Justifications included that indirect protection benefits more people and is likely to be more publicly acceptable.

CONCLUSIONS

In the context of an influenza pandemic, informed citizens were not opposed to prioritising groups at higher risks of adverse outcomes, but if resources and epidemiological conditions allow, achieving population benefits should be a strategic priority. These insights may inform future SARS-CoV-2 vaccination strategies.

Consultations for Influenza-Like Illness in Primary Care in The Netherlands: A Regression Approach

OBJECTIVES

To estimate the general practitioner (GP) consultation rate attributable to influenza in The Netherlands.

METHODS

Regression analysis was performed on the weekly numbers of influenza-like illness (ILI) GP consultations and laboratory reports for influenza virus types A and B and 8 other pathogens over the period 2003-2014 (11 influenza seasons; week 40-20 of the following year).

RESULTS

In an average influenza season, 27% and 11% of ILI GP consultations were attributed to infection by influenza virus types A and B, respectively. Influenza is therefore responsible for approximately 107 000 GP consultations (651/100 000) each year in The Netherlands. GP consultation rates associated with influenza infection were highest in children under 5 years of age, at 667 of 100 000 for influenza A and 258 of 100 000 for influenza B. Influenza virus infection was found to be the predominant cause of ILI-related GP visits in all age groups except children under 5, in which respiratory syncytial virus (RSV) infection was found to be the main contributor.

CONCLUSIONS

The burden of influenza in terms of GP consultations is considerable. Overall, influenza is the main contributor to ILI. Although ILI symptoms in children under 5 years of age are most often associated with RSV infection, the majority of visits related to influenza occur among children under 5 years of age.

Cost-Effectiveness of Quadrivalent Versus Trivalent Influenza Vaccination in the Dutch National Influenza Prevention Program

OBJECTIVES

As of 2019, quadrivalent influenza vaccine (QIV) has replaced trivalent influenza vaccine (TIV) in the national immunization program in The Netherlands. Target groups are individuals of 60+ years of age and those with chronic diseases. The objective was to estimate the incremental break-even price of QIV over TIV at a threshold of €20 000 per quality-adjusted life-year (QALY).

METHODS

An age-structured compartmental dynamic model was adapted for The Netherlands to assess health outcomes and associated costs of vaccinating all individuals at higher risk for influenza with QIV instead of TIV over the seasons 2010 to 2018. Influenza incidence rates were derived from a global database. Other parameters (probabilities, QALYs and costs) were extracted from the literature and applied according to Dutch guidelines. A threshold of €20 000 per QALY was applied to estimate the incremental break-even prices of QIV versus TIV. Sensitivity analyses were performed to test the robustness of the model outcomes.

RESULTS

Retrospectively, vaccination with QIV instead of TIV could have prevented on average 9500 symptomatic influenza cases, 2130 outpatient visits, 84 hospitalizations, and 38 deaths per year over the seasons 2010 to 2018. This translates into 385 QALYs and 398 life-years potentially gained. On average, totals of €431 527 direct and €2 388 810 indirect costs could have been saved each year.

CONCLUSION

Using QIV over TIV during the influenza seasons 2010 to 2018 would have been cost-effective at an incremental price of maximally €3.81 (95% confidence interval, €3.26-4.31). Sensitivity analysis showed consistent findings on the incremental break-even price in the same range.

Cost-Effectiveness of Pediatric Influenza Vaccination in The Netherlands

OBJECTIVE

This study evaluates the cost-effectiveness of extending the Dutch influenza vaccination program for elderly and medical high-risk groups to include pediatric influenza vaccination, taking indirect protection into account.

METHODS

An age-structured dynamic transmission model was used that was calibrated to influenza-associated GP visits over 4 seasons (2010-2011 to 2013-2014). The clinical and economic impact of different pediatric vaccination strategies were compared over 20 years, varying the targeted age range, the vaccine type for children or elderly and high-risk groups. Outcome measures include averted symptomatic infections and deaths, societal costs and quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios. Costs and QALYs were discounted at 4% and 1.5% annually.

RESULTS

At an assumed coverage of 50%, adding pediatric vaccination for 2- to 17-year-olds with quadrivalent live-attenuated vaccine to the current vaccination program for elderly and medical high-groups with quadrivalent inactivated vaccine was estimated to avert, on average, 401 820 symptomatic cases and 72 deaths per year. Approximately half of averted symptomatic cases and 99% of averted deaths were prevented in other age groups than 2- to 17-year-olds due to herd immunity. The cumulative discounted 20-year economic impact was 35 068 QALYs gained and €1687 million saved, that is, the intervention was cost-saving. This vaccination strategy had the highest probability of being the most cost-effective strategy considered, dominating pediatric strategies targeting 2- to 6-year-olds or 2- to 12-year-olds or strategies with trivalent inactivated vaccine.

CONCLUSION

Modeling indicates that introducing pediatric influenza vaccination in The Netherlands is cost-saving, reducing the influenza-related disease burden substantially.

Cost-Effectiveness of Routine Childhood Vaccination Against Seasonal Influenza in Germany

OBJECTIVES

In Germany, routine influenza vaccination with quadrivalent influenza vaccines (QIV) is recommended and reimbursed for individuals ≥60 years of age and individuals with underlying chronic conditions. The present study examines the cost-effectiveness of a possible extension of the recommendation to include strategies of childhood vaccination against seasonal influenza using QIV.

METHODS

A dynamic transmission model was used to examine the epidemiological impact of different childhood vaccination strategies. The outputs were used in a health economic decision tree to calculate the costs per quality-adjusted life year (QALY) gained from a societal and a third-party payer (TPP) perspective. Strain-specific epidemiology, vaccine uptake, and vaccine efficacy data from the 10 non-pandemic seasons from 2003/2004 to 2013/2014 were used, and cost data were drawn mainly from a health insurance claims data analysis and supplemented by estimates from literature. Uncertainty is explored via scenario, deterministic, and probabilistic sensitivity analyses.

RESULTS

Vaccinating 2- to 9-year-olds with QIV assuming a vaccine uptake of 40% is cost-saving with a benefit-cost ratio of 1.66 from a societal perspective and an incremental cost-effectiveness ratio of €998/QALY from a TPP perspective. Lower and higher vaccine uptakes show marginal effects, while extending the target group to 2- to 17-year-olds further increases the health benefits while still being below the willingness-to-pay (WTP) threshold. Assuming no vaccine-induced herd protection has a negative effect on the cost-effectiveness ratio, but childhood vaccination remains cost-effective.

CONCLUSION

Routine childhood vaccination against seasonal influenza in Germany is most likely to be cost-saving from a societal perspective and highly cost-effective from a TPP perspective.

Optimising age coverage of seasonal influenza vaccination in England: A mathematical and health economic evaluation

For infectious disease prevention, policy-makers are typically required to base policy decisions in light of operational and monetary restrictions, prohibiting implementation of all candidate interventions. To inform the evidence-base underpinning policy decision making, mathematical and health economic modelling can be a valuable constituent.

Applied to England, this study aims to identify the optimal target age groups when extending a seasonal influenza vaccination programme of at-risk individuals to those individuals at low risk of developing complications following infection. To perform this analysis, we utilise an age- and strain-structured transmission model that includes immunity propagation mechanisms which link prior season epidemiological outcomes to immunity at the beginning of the following season. Making use of surveillance data from the past decade in conjunction with our dynamic model, we simulate transmission dynamics of seasonal influenza in England from 2012 to 2018. We infer that modified susceptibility due to natural infection in the previous influenza season is the only immunity propagation mechanism to deliver a non-negligible impact on the transmission dynamics. Further, we discerned case ascertainment to be higher for young infants compared to adults under 65 years old, and uncovered a decrease in case ascertainment as age increased from 65 to 85 years of age.

Our health economic appraisal sweeps vaccination age space to determine threshold vaccine dose prices achieving cost-effectiveness under differing paired strategies. In particular, we model offering vaccination to all those low-risk individuals younger than a given age (but no younger than two years old) and all low-risk individuals older than a given age, while maintaining vaccination of at-risk individuals of any age. All posited strategies were deemed cost-effective. In general, the addition of low-risk vaccination programmes whose coverage encompassed children and young adults (aged 20 and below) were highly cost-effective. The inclusion of elder age-groups to the low-risk programme typically lessened the cost-effectiveness. Notably, elderly-centric programmes vaccinating from 65-75 years and above had the least permitted expense per vaccine.

Vaccination is an established method to provide protection against seasonal influenza and its complications. Yet, a need to administer an updated vaccine on an annual basis presents significant operational challenges and sizeable costs. Consequently, policy makers typically have to decide how to deploy a finite amount of resource in a cost-effective manner. A combination of mathematical and health economic modelling can be used to address such a question. Here, we developed an age- and strain-structured mathematical model for seasonal influenza transmission dynamics that incorporates mechanisms for immunity propagation, which we used to reconstruct transmission dynamics of seasonal influenza in England from 2012 to 2018.

We then performed a health economic evaluation assessing the cost-effectiveness of extending a seasonal influenza vaccination programme of at-risk individuals to also include, for targeted age groups, those individuals at low risk of developing complications following infection. The findings suggest the inclusion of low-risk vaccination programmes whose coverage encompassed children and young adults (aged 20 and below) to be highly cost-effective. In contrast, the inclusion of elder age-groups to the low-risk programme typically lessened the cost-effectiveness.

Seasonal influenza vaccination in Kenya: an economic evaluation using dynamic transmission modelling

BACKGROUND

There is substantial burden of seasonal influenza in Kenya, which led the government to consider introducing a national influenza vaccination programme. Given the cost implications of a nationwide programme, local economic evaluation data are needed to inform policy on the design and benefits of influenza vaccination. We set out to estimate the cost-effectiveness of seasonal influenza vaccination in Kenya.

METHODS

We fitted an age-stratified dynamic transmission model to active surveillance data from patients with influenza from 2010 to 2018. Using a societal perspective, we developed a decision tree cost-effectiveness model and estimated the incremental cost-effectiveness ratio (ICER) per disability-adjusted life year (DALY) averted for three vaccine target groups: children 6-23 months (strategy I), 2-5 years (strategy II) and 6-14 years (strategy III) with either the Southern Hemisphere influenza vaccine (Strategy A) or Northern Hemisphere vaccine (Strategy B) or both (Strategy C: twice yearly vaccination campaigns, or Strategy D: year-round vaccination campaigns). We assessed cost-effectiveness by calculating incremental net monetary benefits (INMB) using a willingness-to-pay (WTP) threshold of 1-51% of the annual gross domestic product per capita ($17-$872).

RESULTS

The mean number of infections across all ages was 2-15 million per year. When vaccination was well timed to influenza activity, the annual mean ICER per DALY averted for vaccinating children 6-23 months ranged between $749 and $1385 for strategy IA, $442 and $1877 for strategy IB, $678 and $4106 for strategy IC and $1147 and $7933 for strategy ID. For children 2-5 years, it ranged between $945 and $1573 for strategy IIA, $563 and $1869 for strategy IIB, $662 and $4085 for strategy IIC, and $1169 and $7897 for strategy IID. For children 6-14 years, it ranged between $923 and $3116 for strategy IIIA, $1005 and $2223 for strategy IIIB, $883 and $4727 for strategy IIIC and $1467 and $6813 for strategy IIID. Overall, no vaccination strategy was cost-effective at the minimum ($17) and median ($445) WTP thresholds. Vaccinating children 6-23 months once a year had the highest mean INMB value at $872 (WTP threshold upper limit); however, this strategy had very low probability of the highest net benefit.

CONCLUSION

Vaccinating children 6-23 months once a year was the most favourable vaccination option; however, the strategy is unlikely to be cost-effective given the current WTP thresholds.

Constrained Optimization for the Selection of Influenza Vaccines to Maximize the Population Benefit: A Demonstration Project

BACKGROUND

Influenza is an infectious disease causing a high annual economic and public health burden. The most efficient management of the disease is through prevention with vaccination. Many influenza vaccines are available, with varying efficacy and cost, targeting different age groups. Therefore, strategic decision-making about which vaccine to deliver to whom is warranted to improve efficiency.

OBJECTIVE

We present the use of a constrained optimization (CO) model to evaluate targeted strategies for providing influenza vaccines in three adult age groups in the USA.

METHODS

CO was considered for identifying an influenza vaccine provision strategy that maximizes the benefits at constrained annual budgets, by prioritizing vaccines based on return on investment. The approach optimizes a set of predefined outcome measures over several years resulting from an increasing investment using the best combination of influenza vaccines.

RESULTS

Results indicate the importance of understanding the relative differences in benefits for each vaccine type within and across age groups. Scenario and threshold analyses demonstrate the impact of changing budget distribution over time, price setting per vaccine type, and selection of outcome measure to optimize.

CONCLUSION

Significant gains in cost efficiency can be realized for a decision maker using a CO model, especially for a disease like influenza with many vaccine options. Testing the model under different scenarios offers powerful insights into maximum achievable benefit overall and per age group within the predefined constraints of a vaccine budget.

From trivalent to quadrivalent influenza vaccines: Public health and economic burden for different immunization strategies in Spain

PURPOSE

Quadrivalent influenza vaccine (QIV) includes the same strains as trivalent influenza vaccine (TIV) plus an additional B strain of the other B lineage. The aim of the study was to analyse the public health and economic impact of replacing TIV with QIV in different scenarios in Spain.

METHODS

A dynamic transmission model was developed to estimate the number of influenza B cases prevented under TIV and QIV strategies (<65 years (high risk) and ≥65 years). This model considers cross-protective immunity induced by different lineages of influenza B. The output of the transmission model was used as input for a decision tree model that estimated the economic impact of switching TIV to QIV. The models were populated with Spanish data whenever possible. Deterministic univariate and probabilistic multivariate sensitivity analyses were performed.

RESULTS

Replacing TIV with QIV in all eligible patients with current vaccine coverage in Spain may have prevented 138,707 influenza B cases per season and, therefore avoided 10,748 outpatient visits, 3,179 hospitalizations and 192 deaths. The replacement could save €532,768 in outpatient visit costs, €13 million in hospitalization costs, and €3 million in costs of influenza-related deaths per year. An additional €5 million costs associated with productivity loss could be saved per year, from the societal perspective. The budget impact from societal perspective would be €6.5 million, and the incremental cost-effectiveness ratio (ICER) €1,527 per quality-adjusted life year (QALY). Sensitivity analyses showed robust results. In additional scenarios, QIV also showed an impact at public health level reducing influenza B related cases, outpatient visits, hospitalizations and deaths.

CONCLUSIONS

Our results show public health and economic benefits for influenza prevention with QIV. It would be an efficient intervention for the Spanish National Health Service with major health benefits especially in the population ≥65-year.

Centralized Reminder/Recall to Increase Influenza Vaccination Rates: A Two-State Pragmatic Randomized Trial

OBJECTIVE

Centralized reminder/recall (C-R/R) by health departments using immunization information systems is more effective and cost effective than practice-based approaches for increasing childhood vaccines but has not been studied for influenza vaccination. We assessed effectiveness and cost of C-R/R for increasing childhood influenza vaccination compared with usual care.

METHODS

Within Colorado (CO) and New York (NY), random samples of primary care practices (pediatric, family medicine, and health center) were selected proportionate to where children are served-65 practices (N = 54,353 children) in CO; 101 practices (N = 65,777) in NY. We conducted 4-arm RCTs per state (1, 2, or 3 autodial reminders vs usual care), with randomization at the patient level within practices from 10/2016 to 1/2017.

RESULTS

In CO, the maximum absolute difference in receipt of ≥1 influenza vaccine was 1.7% between the 2 R/R group and control (adjusted risk ratio [ARR] of 1.06 [1.01, 1.10]); other R/R arms did not differ significantly. In NY, ARRs for the study arms versus control varied from 1.05 (1.01, 1.10) for 3 R/R to 1.06 (1.01, 1.11) for 1-2 R/R groups and maximum absolute increase in vaccination was 0.6%. In time-to-event analyses, study arm was a significant predictor of vaccination in CO (P = .001) but not in NY. Costs/child randomized to one message were $.17 in CO and $.23 in NY.

CONCLUSIONS

C-R/R for influenza vaccine using autodial had low-level effects on increasing influenza rates in 2 states. Given the feasibility and low cost of C-R/R in previous trials, its utility for influenza should be re-examined using different modalities.

Influenza in the school-aged population in Mexico: burden of disease and cost-effectiveness of vaccination in children

BACKGROUND

The current national influenza vaccination schedule in Mexico does not recommend vaccination in the school-aged population (5-11 years). Currently, there are limited data from middle-income countries analysing the cost-effectiveness of influenza vaccination in this population. We explored the clinical effects and economic benefits of expanding the current national influenza vaccination schedule in Mexico to include the school-aged population.

METHODS

A static 1-year model incorporating herd effect was used to assess the cost-effectiveness of expanding the current national influenza vaccination schedule of Mexico to include the school-aged population. We performed a cross-sectional epidemiological study using influenza records (2009-2018), death records (2010-2015), and discharge and hospitalisation records (2010-2016), from the databases of Mexico's Influenza Surveillance System (SISVEFLU), the National Mortality Epidemiological and Statistical System (SEED), and the Automated Hospital Discharge System (SAEH), respectively. Cost estimates for influenza cases were based on 7 scenarios using data analysed from SISVEFLU; assumptions for clinical management of cases were defined according to Mexico's national clinical guidelines. The primary health outcome for this study was the number of influenza cases avoided. A sensitivity analysis was performed using conservative and optimistic parameters (vaccination coverage: 30% / 70%, Vaccine effectiveness: 19% / 68%).

RESULTS

It was estimated that expanding the influenza immunisation programme to cover school-aged population in Mexico over the 2018-2019 influenza season would result in 671,461 cases of influenza avoided (50% coverage and 50% effectiveness assumed). Associated with this were 262,800 fewer outpatient consultations; 154,100 fewer emergency room consultations; 97,600 fewer hospitalisations, and 15 fewer deaths. Analysis of cases avoided by age-group showed that 55.4% of them were in the school-aged population, and the decrease in outpatient consultations was largest in this population. There was an overall decrease in the economic burden for the Mexican health care system of 111.9 million US dollars; the immunization programme was determined to be cost-saving in the base, conservative and optimistic scenarios.

CONCLUSIONS

Vaccinating school-aged population in Mexico would be cost-effective; expansion of the current national vaccination schedule to this age group is supported.

Optimal Design of Population-Level Financial Incentives of Influenza Vaccination for the Elderly

OBJECTIVES

To identify how monetary incentives affect influenza vaccination uptake rate using a randomized control experiment and to subsequently design an optimal incentive program in Singapore, a high-income country with a market-based healthcare system.

METHODS

4000 people aged ≥65 were randomly assigned to 4 treatment groups (1000 each) and were offered a monetary incentive (in shopping vouchers) if they chose to participate. The baseline group was invited to complete a questionnaire with incentives of 10 Singapore dollars (SGD; where 1 SGD ≈ 0.73 USD), whereas the other three groups were invited to complete the questionnaire and be vaccinated against influenza at their own cost of around 32 SGD, in return for incentives of 10, 20, or 30 SGD.

RESULTS

Increasing the total incentive for vaccination and reporting from 10 to 20 SGD increased participation in vaccination from 4.5% to 7.5% (P < .001). Increasing the total incentive from 20 to 30 SGD increased the participation rate to 9.2%, but this was not statistically significantly different from a 20-SGD incentive. The group of nonworking elderly were more sensitive to changes in incentives than those who worked. In addition to working status, the effects of increasing incentives on influenza vaccination rates differed by ethnicity, socio-economic status, household size, and a measure of social resilience. There were no significant differential effects by age group, gender, or education, however. The cost of the program per completed vaccination under a 20-SGD incentive is 36.80 SGD, which was the lowest among the three intervention arms. For a hypothetical population-level financial incentive program to promote influenza vaccination among the elderly, accounting for transmission dynamics, an incentive between 10 and 20 SGD minimizes the cost per completed vaccination from both governmental and health system perspectives.

CONCLUSIONS

Appropriate monetary incentives can boost influenza vaccination rates. Increasing monetary incentives for vaccination from 10 to 20 SGD can improve the influenza vaccination uptake rate, but further increasing the monetary incentive to 30 SGD results in no additional gains. A partial incentive may therefore be considered to improve vaccination coverage in this high-risk group.

Program cost analysis of influenza vaccination of health care workers in Albania

BACKGROUND

Since 2012, WHO has recommended influenza vaccination for health care workers (HCWs), which has different costs than routine infant immunization; however, few cost estimates exist from low- and middle-income countries. Albania, a middle-income country, has self-procured influenza vaccine for some HCWs since 2014, supplemented by vaccine donations since 2016 through the Partnership for Influenza Vaccine Introduction (PIVI). We conducted a cost analysis of HCW influenza vaccination in Albania to inform scale-up and sustainability decisions.

METHODS

We used the WHO's Seasonal Influenza Immunization Costing Tool (SIICT) micro-costing approach to estimate incremental costs from the government perspective of facility-based vaccination of HCWs in Albania with trivalent inactivated influenza vaccine for the 2018-19 season based on 2016-17 season data from administrative records, key informant consultations, and a convenience sample of site visits. Scenario analyses varied coverage, vaccine presentation, and vaccine prices.

RESULTS

In the baseline scenario, 13,377 HCWs (70% of eligible HCWs) would be vaccinated at an incremental financial cost of US$61,296 and economic cost of US$161,639. Vaccine and vaccination supplies represented the largest share of financial (89%) and economic costs (44%). Per vaccinated HCW financial cost was US$4.58 and economic cost was US$12.08 including vaccine and vaccination supplies (US$0.49 and US$6.76 respectively without vaccine and vaccination supplies). Scenarios with higher coverage, pre-filled syringes, and higher vaccine prices increased total economic and financial costs, although the economic cost per HCW vaccinated decreased with higher coverage as some costs were spread over more HCWs. Across all scenarios, economic costs were <0.07% of Albania's estimated government health expenditure, and <5.07% of Albania's estimated immunization program economic costs.

CONCLUSIONS

Cost estimates can help inform decisions about scaling up influenza vaccination for HCWs and other risk groups.

Estimating the Effect of a National Pharmacy-Led Influenza Vaccination Voucher Program on Morbidity, Mortality, and Costs

BACKGROUND

Influenza (also known as "flu") is estimated to cause between 12,000 and 79,000 deaths annually. Vaccinations are beneficial in preventing influenza cases and reducing the likelihood of severe outcomes. Unfortunately, vaccination coverage is low among uninsured populations. Removing the cost barrier can help increase vaccination coverage in this group, averting flu cases and related morbidity and costs.

OBJECTIVE

To model the potential effect of providing no-cost flu vaccinations to uninsured individuals on influenza-related morbidity, mortality, and costs.

METHODS

In collaboration with the Department of Health and Human Services and local agencies, Walgreens pharmacies provided free flu vaccinations through a nationwide voucher distribution program. We calculated the redemption rate, potentially averted cases, and estimated cost savings for the 2015-2016 and 2016-2017 flu seasons. Using incidence and vaccine effectiveness estimates from the Centers for Disease Control and Prevention, we calculated the rate of influenza in the general population and the estimated cases averted based on the number of redeemed vouchers. We applied patient age along with parameters from published studies to estimate averted ambulatory care visits, hospitalizations, mortality, productively losses, and overall related costs.

RESULTS

During the 2015-2016 flu season, the pharmacy chain distributed 600,000 vouchers with a redemption rate of 52.3%, resulting in 314,033 flu vaccinations. Improvements were subsequently made to the distribution process to increase utilization rates. There were 400,000 vouchers distributed during the 2016-2017 season with a higher redemption rate of 87.2%, resulting in 348,924 flu vaccinations. The estimated number of potentially averted cases was higher during the 2016-2017 season (13,347) than the 2015-2016 season (11,537) due to a higher redemption rate and increased flu activity. Taken together, we estimated that 8,621 ambulatory care visits, 314 hospitalizations, and 15 deaths were averted due to the flu voucher program. Averted health care costs totaled $937,494 in ambulatory care visits and $3,510,055 in hospitalizations. Averted productivity losses ranged from $4,473,509 to $14,613,502.

CONCLUSIONS

This study demonstrates the effectiveness of a pharmacy-led partnership with local community-based organizations to promote flu vaccinations among uninsured individuals. Our model found that a no-cost flu voucher program has the potential to reduce influenza-related morbidity, mortality, and costs.

DISCLOSURES

This study was funded by Walgreen Co. All authors are employees of Walgreen Co. and affiliated with Walgreens Center for Health and Wellbeing Research. Findings from this study were presented as a podium presentation at the Academy of Managed Care Pharmacy Nexus 2018; October 22-25, 2018; Orlando, FL.

Cost-Effectiveness Analysis for Influenza Vaccination Coverage and Timing in Tropical and Subtropical Climate Settings: A Modeling Study

BACKGROUND

The lack of seasonality in influenza epidemics in the tropics makes the application of well-established temperate zone national vaccination plans challenging.

OBJECTIVES

We developed an individual-based simulation model to study optimal vaccination scheduling and assess cost-effectiveness of these vaccination schedules in scenarios of no influenza seasonality and the seasonality regimes of Singapore, Taipei, and Tokyo.

METHODS

The simulation models heterogeneities in human contact networks, levels of protective antibodies following infection, the effectiveness of the influenza vaccine, and seasonality. Using a no intervention baseline, we consider 3 alternative vaccination strategies: (1) annual vaccination for a percentage of the elderly, (2) biannual vaccination for a percentage of the elderly, and (3) annual vaccination for all elderly and a fraction of the remaining population. We considered 5 vaccination uptake rates for each strategy and modeled the estimated costs, quality-adjusted life years, and incremental cost-effectiveness ratios (ICERs), indicating the cost-effectiveness of each scenario.

RESULTS

In Singapore, annual vaccination for a proportion of elderly is largely cost-effective. However, with fixed uptake rates, partial biannual vaccination for the elderly yields a higher ICER than partial annual vaccination for the elderly, resulting in a cost-ineffective ICER. The most optimal strategy is the total vaccination of all the elderly and a proportion of individuals from other age groups, which results in a cost-saving ICER. This finding is consistent across different seasonality regimes.

CONCLUSIONS

Tropical countries like Singapore can have comparably cost-effective vaccination strategies as found in countries with winter epidemics. The vaccination of all the elderly and a proportion of other age groups is the most cost-effective strategy, supporting the need for an extensive national influenza vaccination program.

Future epidemiological and economic impacts of universal influenza vaccines

The efficacy of influenza vaccines, currently at 44%, is limited by the rapid antigenic evolution of the virus and a manufacturing process that can lead to vaccine mismatch. The National Institute of Allergy and Infectious Diseases (NIAID) recently identified the development of a universal influenza vaccine with an efficacy of at least 75% as a high scientific priority. The US Congress approved $130 million funding for the 2019 fiscal year to support the development of a universal vaccine, and another $1 billion over 5 y has been proposed in the Flu Vaccine Act. Using a model of influenza transmission, we evaluated the population-level impacts of universal influenza vaccines distributed according to empirical age-specific coverage at multiple scales in the United States. We estimate that replacing just 10% of typical seasonal vaccines with 75% efficacious universal vaccines would avert ∼5.3 million cases, 81,000 hospitalizations, and 6,300 influenza-related deaths per year. This would prevent over $1.1 billion in direct health care costs compared to a typical season, based on average data from the 2010-11 to 2018-19 seasons. A complete replacement of seasonal vaccines with universal vaccines is projected to prevent 17 million cases, 251,000 hospitalizations, 19,500 deaths, and $3.5 billion in direct health care costs. States with high per-hospitalization medical expenses along with a large proportion of elderly residents are expected to receive the maximum economic benefit. Replacing even a fraction of seasonal vaccines with universal vaccines justifies the substantial cost of vaccine development.

Insurance Reimbursements for Routinely Recommended Adult Vaccines in the Private Sector

INTRODUCTION

Financial concerns are frequently cited by providers as a barrier to adult vaccination. This study assessed insurance reimbursements to providers for administering vaccines to adults in the private sector.

METHODS

This study, conducted in 2018, used the 2016 MarketScan Commercial Claims and Encounters Database and included vaccination visits made by adults aged 19-64 years. Four routinely recommended vaccines targeted at adults were included: tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap); tetanus and diphtheria toxoids (Td); zoster; and influenza. The mean reimbursements for vaccine purchase and administration were reported and examined by state, metropolitan statistical area, provider type, and insurance plan type. Using the private vaccine purchase price published by the Centers for Disease Control and Prevention (CDC), the study reported the proportion of vaccination visits receiving reimbursements above the CDC-published price.

RESULTS

The mean vaccine administration reimbursement was $25.80 for the first dose and $14.71 for additional doses in the same visit. The mean vaccine purchase reimbursement was $44.15 for Tdap, $25.78 for Td, and $216.05 for the zoster vaccine; the unweighted mean for the four examined influenza vaccines was $17.25. Reimbursements varied widely by state. Vaccine reimbursements exceeded the CDC-published price for most visits where Tdap (71.4%), zoster (87.8%), and three of four influenza (61.5%-88.5%) vaccines were administered but only for 25.8% of visits where Td was given.

CONCLUSIONS

On average, reimbursements for administering vaccines to privately insured adults were adequate for most private practices. However, providers' financial concerns may vary across geographic locations.

Thermal Stabilization of Viral Vaccines in Low-Cost Sugar Films

Most currently available vaccines, particularly live vaccines, require the cold chain, as vaccine efficacy can be significantly hampered if they are not stored in a temperature range of 2-8 °C at all times. This necessity places a tremendous financial and logistical burden on vaccination programs, particularly in the developing world. The development of thermally stable vaccines can greatly alleviate this problem and, in turn, increase vaccine accessibility worldwide. In this paper, we detail a simple and cost-effective method for stabilizing live vaccines that uses FDA-approved materials. To this end, we dried enveloped DNA (Herpes Simplex Virus type 2) and RNA (Influenza A virus) viral vaccines in a pullulan and trehalose mixture. The results of these studies showed that the live-attenuated HSV-2 vaccine retained its efficacy for at least 2 months of storage at 40 °C, while the inactivated influenza vaccine was able to retain its immunogenicity for at least 3 months of storage at 40 °C. This work presents a simple approach that allows thermo-sensitive vaccines to be converted into thermo-stable vaccines that do not require refrigeration, thus contributing to the improvement of vaccine deployment throughout the world.

Cost-effectiveness of influenza vaccine strategies for the elderly in South Korea

OBJECTIVES

Despite a high vaccine uptake rate of over 80% in South Korea, the disease burden of influenza is still high among the elderly, which may be due to low effectiveness of vaccines. Therefore, the cost-effectiveness of use among the elderly was analyzed in order to compare the current trivalent influenza vaccine (TIV) with a quadrivalent influenza vaccine (QIV) or MF59-adjuvanted trivalent influenza vaccine (ATIV).

METHODS

A static lifetime Markov model was used. It was assumed that the model would be repeated until individuals reached the age of 100. Cost-effectiveness was analyzed across three age groups (65-74 years, 75-84 years, and ≥85 years), and the at-risk group was studied.

RESULTS

Compared to the TIV, the QIV was expected to reduce the number of influenza infections by 342,873, complications by 17,011, hospitalizations by 8,568, and deaths by 2,031. The QIV was highly cost-effective when compared to the TIV, with a base case incremental cost-effectiveness ratio (ICER) estimated at USD 17,699/QALY (1USD = 1,151KRW), and the ICER decreased with age and was USD 3,431/QALY in the group aged 85 and above. Sensitivity analysis revealed that the ICER was sensitive to the QIV price, the proportion of influenza B, and vaccine mismatching. On the other hand, the ATIV was expected to reduce the number of influenza cases and complications by 1,812,395 and 89,747, respectively, annually, yielding cost-saving among all ages. ATIV price and vaccine efficacy were the most influential parameters for the ICER of ATIV.

CONCLUSIONS

The QIV and ATIV strategies were considered more cost-effective in comparison to the TIV for vaccination strategies implemented for the elderly. However, owing to a lack of data on the effectiveness of ATIV among the elderly, a large-scale effectiveness study is required.

Cost Effectiveness of Quadrivalent Influenza Vaccines Compared with Trivalent Influenza Vaccines in Young Children and Older Adults in Korea

INTRODUCTION

Trivalent influenza vaccines (TIVs) are currently reimbursed for subjects aged ≥ 65 years and children between 6 and 59 months of age under a national immunization program in South Korea. Quadrivalent influenza vaccines (QIVs) are expected to address the potential problem of influenza B-lineage mismatch for TIVs.

OBJECTIVE

The objective of this analysis was to compare the cost effectiveness of QIV versus TIV in children aged 6-59 months and older adults ≥ 65 years of age in South Korea.

METHODS

A 1-year static population model was employed to compare the costs and outcomes of a QIV vaccination program compared with TIV in children aged 6-59 months and older adults ≥ 65 years of age in South Korea. Influenza-related parameters (probabilities, health resource use, and costs) were derived from an analysis of the National Health Insurance System claims database between 2010 and 2013 under a broad and narrow set of International Classification of Diseases, Tenth Revision (ICD-10) codes used to identify influenza. Other inputs were extracted from published literature. Incremental cost-effectiveness ratios (2016 South Korean Won [KRW] per quality-adjusted life-year [QALY] gained) were estimated using a 'limited' societal perspective as per the Korean pharmacoeconomic guidelines. QALYs lost due to premature mortality were discounted at 5% annually.

RESULTS

For both age groups combined, under the narrow definition of influenza, QIV is expected to prevent nearly 16,000 (2923 in children and 13,011 in older adults) medically attended influenza cases, nearly 8000 (672 in children, 7048 in older adults) cases of complications, and over 230 (0 in children, 238 in older adults) deaths annually compared with TIV. The impact of using QIV versus TIV in this setting translates into savings of KRW 24 billion (KRW 0.6 billion in children, KRW 23.4 billion in older adults) in annual medical costs, and over 2100 (18 in children, 2084 in older adults) QALYs. Under the broad definition, the corresponding results are over 190,000 (50,697 in children, 140,644 in older adults) influenza cases, over 37,000 (12,623 in children, 24,526 in older adults) complications, 270 deaths (0 in children, 270 in older adults), KRW 94.22 billion (KRW 16 billion in children, KRW 78.2 billion in older adults), and over 3500 QALYs saved (316 in children, 3260 in older adults).

CONCLUSION

The use of QIV over TIV was estimated to not be cost effective in children 6-59 months of age, but cost saving in older adults, using the narrow definition of influenza; however, QIV use was cost saving in both age groups using the broad definition. QIV is expected to yield more benefits in older adults ≥ 65 years of age than in children aged 6-59 months due to higher influenza-related mortality and costs among the older adults. Further analyses considering the indirect effects of influenza vaccination in children are required.

[Cost-effectiveness of vaccines for the prevention of seasonal influenza in different age groups: a systematic review]

BACKGROUND

Given the economic burden of seasonal influenza for the healthcare system, we performed a systematic review aiming to update available evidence on the cost-effectiveness of vaccination of seasonal influenza in different age groups, including children.

METHODS

A systematic review of the literature on economic evaluations of seasonal influenza vaccination programs in children and adults was carried out. The following databases were searched (January 2013 - April 2018): Medline and PREMEDLINE, EMBASE, EconLit and databases of the Centre for Reviews and Dissemination (DARE, HTA, NHS EED).

RESULTS

A total of 11 economic evaluations were included. Methodological quality of included studies was acceptable. Scientific evidence shows that seasonal influenza vaccination programs in school-age children can be a cost-effective alternative from national health system perspective and can be cost-saving from societal perspective in European countries. However, available evidence does not allow us to conclude that influenza vaccination programs in healthy adults under 65 years of age were a cost-effective alternative in our context, due to the high uncertainty and the lack of studies carried out in Spanish context.

CONCLUSIONS

Vaccination programs for the prevention of seasonal influenza in school-age children (3-16 years) can be a cost-effective strategy.

Canadian older adults' perceptions of effectiveness and value of regular and high-dose influenza vaccines

Influenza vaccination is an important public health intervention for older adults, yet vaccination rates remain suboptimal. We conducted an online survey of Canadians ≥ 65 years to explore satisfaction with publicly-funded standard-dose influenza vaccines, and perceptions of the need for a more effective product. They were provided with information about currently approved influenza vaccines, and were asked about their preferences should all formulations be available for free, and should the recently approved high-dose (HD) vaccine for seniors be available at a cost. From March to April 2017, 5014 seniors completed the survey; mean age was 71.3 ± 5.17 years, 50% were female, and 42.6% had one or more chronic conditions. 3403 (67.9%) had been vaccinated against influenza in the 2016/17 season. Of all respondents, 3460 (69%) were satisfied with the standard-dose influenza vaccines, yet 3067 (61.1%) thought that a more effective vaccine was/may be needed. If HD was only available at a cost, 1426 (28.4%) respondents would consider it, of whom 62.9% would pay $20 or less. If all vaccines were free next season, 1914 (38.2%) would opt for HD (including 12.2% of those who previously rejected influenza vaccines), 856 (17.1%) would choose adjuvanted vaccine, and 558 (11.1%) standard-dose vaccine. 843 (16.8%) of respondents were against vaccines, 451 (9.0%) had no preference and 392 (7.8%) were uncertain. Making this product available through publicly funded programs may be a strategy to increase immunization rates in this population.

[A trial to study the effect of influenza vaccination in the elderly: ethical, feasible and badly needed]

Based on current research, there are no valid reasons to assume that influenza vaccination of people aged 60 and over without any other medical indications, in the context of the national programme of influenza prevention, leads to significant, relevant and cost-effective health benefits. In view of the pressure on health care budgets and the decreasing social willingness to vaccinate, it is of great and urgent importance that the actual effect of influenza vaccination is quantified in a double-blind placebo-controlled randomized trial (RCT) with relevant outcome measures, which does not suffer from the methodological shortcomings of the few previous studies. In order to demonstrate a 10% reduction in hospitalisation for respiratory infections, this RCT should include approximately 100,000 subjects and follow these participants for three years. We consider such a trial feasible in the Dutch situation.

Forecasting demand for maternal influenza immunization in low- and lower-middle-income countries

Immunization of pregnant women against seasonal influenza remains limited in low- and lower-middle-income countries despite being recommended by the World Health Organization (WHO). The WHO/PATH Maternal Influenza Immunization Project was created to identify and address obstacles to delivering influenza vaccines to pregnant women in low resource setting. To gain a better understanding of potential demand from this target group, we developed a model simulating pregnant women populations eligible for vaccination during antenatal care (ANC) services in all low- and lower-middle-income countries. We assessed potential vaccine demand in the context of both seasonal and year-round vaccination strategies and identified the ways that immunization programs may be affected by availability gaps in supply linked to current vaccine production cycles and shelf life duration. Results of our analysis, which includes 54 eligible countries in 2015 for New Vaccine Support from Gavi, the Vaccine Alliance, suggest the demand for influenza vaccines could be 7.7 to 16.0 million doses in 2020, and 27.0 to 61.7 million doses by 2029. If current trends in production capacity and actual production of seasonal influenza vaccines were to continue, global vaccine supply would be sufficient to meet this additional demand—although a majority of countries would face implementation issues linked to timing of supply.

Cost-effectiveness of switching from trivalent to quadrivalent inactivated influenza vaccines for the at-risk population in Italy

Seasonal influenza is caused by two subtypes of influenza A and two lineages of influenza B. Although trivalent influenza vaccines (TIVs) contain both circulating A strains, they contain only a single B-lineage strain. This can lead to mismatches between the vaccine and predominant circulating B lineages, a concern especially for at-risk populations. Quadrivalent influenza vaccines (QIVs) containing a strain from both B lineages have been developed to improve protection against influenza. Here, we used a cost-utility model to examine whether switching from TIV to QIV would be cost-effective for the at-risk population in Italy. Costs were estimated from the payer and societal perspectives. The discount rate for outcomes was 3.0%. Univariate and probabilistic sensitivity analyses were performed to examine the effects of variations in parameters. Switching from TIV to QIV in Italy was estimated to increase quality-adjusted life-years (QALYs) and produce cost savings, including €1.6 million for hospitalization and approximately €2 million in productivity. The incremental cost-effectiveness ratio was €23,426 per QALY from a payer perspective and €21,096 per QALY from a societal perspective. Switching to QIV was most cost-effective for individuals ≥ 65 years of age (€19,170 per QALY). Probabilistic sensitivity analysis showed that the switching from TIV to QIV would be cost-effective for > 91% of simulation at a maximum willingness-to-pay threshold of €40,000 per QALY gained. Although the model did not take herd protection into account, it predicted that the switch from TIV to QIV would be cost-effective for the at-risk population in Italy.

WHO guide on the economic evaluation of influenza vaccination

Influenza is responsible for substantial morbidity and mortality across the globe, with a large share of the total disease burden occurring in low- and middle-income countries (LMICs). There have been relatively few economic evaluations assessing the value of seasonal influenza vaccination in LMICs. The purpose of this guide is to outline the key theoretical concepts and best practice in methodologies and to provide guidance on the economic evaluation of influenza vaccination in LMICs. It outlines many of the influenza vaccine-specific challenges and should help to provide a framework for future evaluations in the area to build upon.

Age- and risk-related appropriateness of the use of available influenza vaccines in the Italian elderly population is advantageous: results from a budget impact analysis

INTRODUCTION

Nowadays, four different types of influenza vaccines are available in Italy: trivalent (TIV), quadrivalent (QIV), MF59-adjuvanted (aTIV) and intradermal TIV (idTIV) inactivated vaccines. Recently, a concept of the appropriateness (i.e. according to the age and risk factors) of the use of different vaccines has been established in Italy. We conducted a budget impact analysis of switching to a policy, in which the Italian elderly (who carry the major disease burden) received the available vaccines according to their age and risk profile.

METHODS

A novel budget impact model was constructed with a time horizon of one influenza season. In the reference scenario the cohort of Italian elderly individuals could receive either available vaccine according to 2017/18 season market share. The alternative scenario envisaged the administration of TIV/QIV to people aged 65-74 years and at low risk of developing influenza-related complications, while aTIV/idTIV were allocated to high-risk 65-74-year-olds and all subjects aged ≥ 75 years.

RESULTS

Switching to the alternative scenario would result in both significant health benefits and net budget savings. Particularly, it would be possible to prevent an additional 8201 cases of laboratory-confirmed influenza, 988 complications, 355 hospitalizations and 14 deaths. Despite the alternative strategy being associated with slightly higher vaccination costs, the total savings derived from fewer influenza events completely resets this increase with net budget savings of € 0.13 million.

CONCLUSIONS

An immunization policy in which influenza vaccines are administered according to the age and risk profile of Italian elderly individuals is advisable.

Economic benefits of sharing and redistributing influenza vaccines when shortages occurred

Background

Recurrent influenza outbreak has been a concern for government health institutions in Taiwan. Over 10% of the population is infected by influenza viruses every year, and the infection has caused losses to both health and the economy. Approximately three million free vaccine doses are ordered and administered to high-risk populations at the beginning of flu season to control the disease. The government recommends sharing and redistributing vaccine inventories when shortages occur. While this policy intends to increase inventory flexibility, and has been proven as widely valuable, its impact on vaccine availability has not been previously reported.

Material and methods

This study developed an inventory model adapted to vaccination protocols to evaluate government recommended polices under different levels of vaccine production. Demands were uncertain and stratified by ages and locations according to the demographic data in Taiwan.

Results

When vaccine supply is sufficient, sharing pediatric vaccine reduced vaccine unavailability by 43% and overstock by 54%, and sharing adult vaccine reduced vaccine unavailability by 9% and overstock by 15%. Redistributing vaccines obtained greater gains for both pediatrics and adults (by 75%). When the vaccine supply is in short, only sharing pediatric vaccine yielded a 48% reduction of unused inventory, while other polices do not improve performances.

Conclusions

When implementing vaccination activities for seasonal influenza intervention, it is important to consider mismatches of demand and vaccine inventory. Our model confirmed that sharing and redistributing vaccines can substantially increase availability and reduce unused vaccines.

Coverage and factors associated with influenza vaccination among kindergarten children 2-7 years old in a low-income city of north-western China (2014-2016)

Influenza vaccination has been shown to be the most effective preventive measure to reduce influenza virus infection and its related morbidity and mortality. Young children aged 6-59 months are recommended as one of the priority groups for seasonal influenza vaccination in China. Our study was conducted to evaluate the level of influenza vaccination coverage during 2014-15 and 2015-16 influenza seasons among kindergarten children aged 2-7 years in Xining, a low-income city of north-western China, and to explore potential factors for noncompliance associated with influenza vaccination. The coverage rate of influenza vaccination was 12.2% (95 CI: 10.6-14.2%) in 2014-15 and 12.8% (95 CI: 11.1-14.7%) in 2015-16. The low coverage rate was found to be primarily associated with the lack of knowledge about influenza vaccine in children's parents. The most common reason for vaccine declination was the concern about adverse reactions of vaccine. Therefore tailored information should be provided by clinician and public health doctors for targeted groups through effective methods to improve public understanding of vaccination.

A systematic review of economic evaluations of seasonal influenza vaccination for the elderly population in the European Union

OBJECTIVES

The Council of the European Union (EU) has recommended that action should be taken to increase influenza vaccination in the elderly population. The aims were to systematically review and critically appraise economic evaluations for influenza vaccination in the elderly population in the EU.

METHODS

Electronic searches of the NHS Economic Evaluation, Health Technology Assessment, MEDLINE and Embase databases were run to identify full economic evaluations. Two levels of screening were used, with explicit inclusion criteria applied by two independent reviewers at each stage. Prespecified data extraction and critical appraisal were performed on identified studies. Results were summarised qualitatively.

RESULTS

Of the 326 search results, screening identified eight relevant studies. Results varied widely, with the incremental cost-effectiveness ratio ranging from being both more effective and cheaper than no intervention to costing €4 59 350 per life-year gained. Cost-effectiveness was most sensitive to variations in influenza strain, vaccination type and strategy, population and modelling characteristics.

CONCLUSIONS

Most studies suggest that vaccination is cost-effective (seven of eight studies identified at least one cost-effective scenario). All but one study used economic models to synthesise data from different sources. The results are uncertain due to the methods used and the relevance and robustness of the data used. Sensitivity analysis to explore these aspects was limited. Integrated, controlled prospective clinical and economic evaluations and surveillance data are needed to improve the evidence base. This would allow more advanced modelling techniques to characterise the epidemiology of influenza more accurately and improve the robustness of cost-effectiveness estimates.

Value for Money in H1N1 Influenza: A Systematic Review of the Cost-Effectiveness of Pandemic Interventions

BACKGROUND

The 2009 A/H1N1 influenza pandemic generated additional data and triggered new studies that opened debate over the optimal strategy for handling a pandemic. The lessons-learned documents from the World Health Organization show the need for a cost estimation of the pandemic response during the risk-assessment phase. Several years after the crisis, what conclusions can we draw from this field of research?

OBJECTIVE

The main objective of this article was to provide an analysis of the studies that present cost-effectiveness or cost-benefit analyses for A/H1N1 pandemic interventions since 2009 and to identify which measures seem most cost-effective.

METHODS

We reviewed 18 academic articles that provide cost-effectiveness or cost-benefit analyses for A/H1N1 pandemic interventions since 2009. Our review converts the studies' results into a cost-utility measure (cost per disability-adjusted life-year or quality-adjusted life-year) and presents the contexts of severity and fatality.

RESULTS

The existing studies suggest that hospital quarantine, vaccination, and usage of the antiviral stockpile are highly cost-effective, even for mild pandemics. However, school closures, antiviral treatments, and social distancing may not qualify as efficient measures, for a virus like 2009's H1N1 and a willingness-to-pay threshold of $45,000 per disability-adjusted life-year. Such interventions may become cost-effective for severe crises.

CONCLUSIONS

This study helps to shed light on the cost-utility of various interventions, and may support decision making, among other criteria, for future pandemics. Nonetheless, one should consider these results carefully, considering these may not apply to a specific crisis or country, and a dedicated cost-effectiveness assessment should be conducted at the time.

Does Choice of Influenza Vaccine Type Change Disease Burden and Cost-Effectiveness in the United States? An Agent-Based Modeling Study

Offering a choice of influenza vaccine type may increase vaccine coverage and reduce disease burden, but it is more costly. This study calculated the public health impact and cost-effectiveness of 4 strategies: no choice, pediatric choice, adult choice, or choice for both age groups. Using agent-based modeling, individuals were simulated as they interacted with others, and influenza was tracked as it spread through a population in Washington, DC. Influenza vaccination coverage derived from data from the Centers for Disease Control and Prevention was increased by 6.5% (range, 3.25%-11.25%), reflecting changes due to vaccine choice. With moderate influenza infectivity, the number of cases averaged 1,117,285 for no choice, 1,083,126 for pediatric choice, 1,009,026 for adult choice, and 975,818 for choice for both age groups. Averted cases increased with increased coverage and were highest for the choice-for-both-age-groups strategy; adult choice also reduced cases in children. In cost-effectiveness analysis, choice for both age groups was dominant when choice increased vaccine coverage by ≥3.25%. Offering a choice of influenza vaccines, with reasonable resultant increases in coverage, decreased influenza cases by >100,000 with a favorable cost-effectiveness profile. Clinical trials testing the predictions made based on these simulation results and deliberation of policies and procedures to facilitate choice should be considered.

A Review of Methods for Analysis of the Expected Value of Information

In recent years, value-of-information analysis has become more widespread in health economic evaluations, specifically as a tool to guide further research and perform probabilistic sensitivity analysis. This is partly due to methodological advancements allowing for the fast computation of a typical summary known as the expected value of partial perfect information (EVPPI). A recent review discussed some approximation methods for calculating the EVPPI, but as the research has been active over the intervening years, that review does not discuss some key estimation methods. Therefore, this paper presents a comprehensive review of these new methods. We begin by providing the technical details of these computation methods. We then present two case studies in order to compare the estimation performance of these new methods. We conclude that a method based on nonparametric regression offers the best method for calculating the EVPPI in terms of accuracy, computational time, and ease of implementation. This means that the EVPPI can now be used practically in health economic evaluations, especially as all the methods are developed in parallel with R functions and a web app to aid practitioners.

Review of seasonal influenza in Canada: Burden of disease and the cost-effectiveness of quadrivalent inactivated influenza vaccines

In the 2015/16 influenza season, the Canadian National Advisory Committee on Immunization (NACI) recommended vaccination with quadrivalent inactivated influenza vaccine (QIV) for infants aged 6-23 months and trivalent inactivated influenza vaccines (TIVs) or QIVs in adults. The objective of this review (GSK study identifier: HO-13-14054) is to examine the epidemiology and disease burden of influenza in Canada and the economic benefits of vaccination. To inform this review, we performed a systematic literature search of relevant Canadian literature and National surveillance data. Influenza B viruses from phylogenetically-distinct lineages (B/Yamagata and B/Victoria) co-circulate in Canada, and are an important cause of influenza complications. Modeling studies, including those postdating the search suggest that switching from TIV to QIV in Canada reduces the burden of influenza and would likely be cost-effective. However, more robust real-world outcomes data is required to inform health policy decision makers on appropriate influenza vaccination strategies for Canada.

Assessment of Public Health and Economic Impact of Intranasal Live-Attenuated Influenza Vaccination of Children in France Using a Dynamic Transmission Model

OBJECTIVES

We estimated the epidemiological and economic impact of extending the French influenza vaccination programme from at-risk/elderly (≥65 years) only to healthy children (2-17 years).

METHODS

A deterministic, age-structured, dynamic transmission model was used to simulate the transmission of influenza in the French population, using the current vaccination coverage with trivalent inactivated vaccine (TIV) in at-risk/elderly individuals (current strategy) or gradually extending the vaccination to healthy children (aged 2-17 years) with intranasal, quadrivalent live-attenuated influenza vaccine (QLAIV) from current uptake up to 50% (evaluated strategy). Epidemiological, medical resource use and cost data were taken from international literature and country-specific information. The model was calibrated to the observed numbers of influenza-like illness visits/year. The 10-year number of symptomatic cases of confirmed influenza and direct medical costs ('all-payer') were calculated for the 0-17- (direct and indirect effects) and ≥18-year-old (indirect effect). The incremental cost-effectiveness ratio (ICER) was calculated for the total population, using a 4% discount rate/year.

RESULTS

Assuming 2.3 million visits/year and 1960 deaths/year, the model calibration yielded an all-year average basic reproduction number (R ₀) of 1.27. In the population aged 0-17 years, QLAIV prevented 865,000 influenza cases/year (58.4%), preventing 10-year direct medical expenses of €374 million. In those aged ≥18 years with unchanged TIV coverage, 1.2 million cases/year were averted (27.6%) via indirect effects (additionally prevented expenses, €457 million). On average, 613 influenza-related deaths were averted annually overall. The ICER was €18,001/life-year gained. The evaluated strategy had a 98% probability of being cost-effective at a €31,000/life-year gained threshold.

CONCLUSIONS

The model demonstrated strong direct and indirect benefits of protecting healthy children against influenza with QLAIV on public health and economic outcomes in France.

Cost-effectiveness of maternal influenza immunization in Bamako, Mali: A decision analysis

Background

Maternal influenza immunization has gained traction as a strategy to diminish maternal and neonatal mortality. However, efforts to vaccinate pregnant women against influenza in developing countries will require substantial investment. We present cost-effectiveness estimates of maternal influenza immunization based on clinical trial data from Bamako, Mali.

Methods

We parameterized a decision-tree model using prospectively collected trial data on influenza incidence, vaccine efficacy, and direct and indirect influenza-related healthcare expenditures. Since clinical trial participants likely had better access to care than the general Malian population, we also simulated scenarios with poor access to care, including decreased healthcare resource utilization and worse influenza-related outcomes.

Results

Under base-case assumptions, a maternal influenza immunization program in Mali would cost $857 (95% UI: $188-$2358) per disability-adjusted life year (DALY) saved. Adjusting for poor access to care yielded a cost-effectiveness ratio of $486 (95% UI: $105-$1425) per DALY saved. Cost-effectiveness ratios were most sensitive to changes in the cost of a maternal vaccination program and to the proportion of laboratory-confirmed influenza among infants warranting hospitalization. Mean cost-effectiveness estimates fell below Mali’s GDP per capita when the cost per pregnant woman vaccinated was $1.00 or less with no adjustment for access to care or $1.67 for those with poor access to care. Healthcare expenditures for lab-confirmed influenza were not significantly different than the cost of influenza-like illness.

Conclusions

Maternal influenza immunization in Mali would be cost-effective in most settings if vaccine can be obtained, managed, and administered for ≤$1.00 per pregnant woman.

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Zusammenfassung. Die soziale und ökonomische Bürde von jährlichen Influenza-Epidemien wird generell unterschätzt. Influenza-Epidemien verursachen neben direkten medizinischen Kosten vor allem indirekte Kosten durch Produktions- und Arbeitsausfall. Hinzu kommen makroökonomische Auswirkungen durch verändertes menschliches Verhalten und reduzierte ökonomische Nachfrage. Die Impfung ist eine einfache, effektive Massnahme mit der man sich und sein Umfeld gegen eine Infektion schützen kann. Viele Studien zeigten, dass die Impfung gegen Influenza kosteneffektiv und in gewissen Zielpopulationen sogar kostensparend ist.

Total Economic Consequences of an Influenza Outbreak in the United States

Pandemic influenza represents a serious threat not only to the population of the United States, but also to its economy. In this study, we analyze the total economic consequences of potential influenza outbreaks in the United States for four cases based on the distinctions between disease severity and the presence/absence of vaccinations. The analysis is based on data and parameters on influenza obtained from the Centers for Disease Control and the general literature. A state-of-the-art economic impact modeling approach, computable general equilibrium, is applied to analyze a wide range of potential impacts stemming from the outbreaks. This study examines the economic impacts from changes in medical expenditures and workforce participation, and also takes into consideration different types of avoidance behavior and resilience actions not previously fully studied. Our results indicate that, in the absence of avoidance and resilience effects, a pandemic influenza outbreak could result in a loss in U.S. GDP of $25.4 billion, but that vaccination could reduce the losses to $19.9 billion. When behavioral and resilience factors are taken into account, a pandemic influenza outbreak could result in GDP losses of $45.3 billion without vaccination and $34.4 billion with vaccination. These results indicate the importance of including a broader set of causal factors to achieve more accurate estimates of the total economic impacts of not just pandemic influenza but biothreats in general. The results also highlight a number of actionable items that government policymakers and public health officials can use to help reduce potential economic losses from the outbreaks.

Potential Cost-Effectiveness of an Influenza Vaccination Program Offering Microneedle Patch for Vaccine Delivery in Children

Objective

The influenza vaccine coverage rate of children is low in Hong Kong. Microneedle patches (MNPs) is a technology under development for painless delivery of vaccines. This study aimed to examine the potential clinical outcomes and direct medical costs of an influenza program offering MNP vaccine to children who have declined intramuscular (IM) vaccine in Hong Kong.

Methods

A decision model was designed to compare potential outcomes between IM vaccine program and a program offering MNP vaccine to those declined IM vaccine (IM/MNP program) in a hypothetical cohort of children over one-year time horizon. The model outcomes included direct medical cost, influenza infection rate, mortality rate, and quality-adjusted life-years (QALYs) loss. Model inputs were retrieved from published literature. Sensitivity analyses were performed to examine the robustness of model results.

Results

In base-case analysis, IM/MNP program was more costly per child (USD19.13 versus USD13.69; USD1 = HKD7.8) with lower influenza infection rate (98.9 versus 124.8 per 1,000 children), hospitalization rate (0.83 versus 1.05 per 1,000 children) and influenza-related mortality rate (0.00042 versus 0.00052 per 1,000 children) when compared to IM program. The incremental cost per QALY saved (ICER) of IM/MNP program versus IM program was 27,200 USD/QALY. Using gross domestic product (GDP) per capita of Hong Kong (USD40,594) as threshold of willingness-to-pay (WTP) per QALY, one-way sensitivity analysis found ICER of IM/MNP to exceed WTP when duration of illness in outpatient setting was <5.7 days or cost per MNP vaccine was >1.39-time of IM vaccine cost. In 10,000 Monte Carlo simulations, IM/MNP program was the preferred option in 57.28% and 91.68% of the time, using 1x and 3x GDP per capita as WTP threshold, respectively.

Conclusion

Acceptance of IM/MNP program as the preferred program was subject to the WTP threshold, duration of illness in outpatient settings, and cost of MNP vaccine.

Yeast Surface-Displayed H5N1 Avian Influenza Vaccines

Highly pathogenic H5N1 avian influenza viruses pose a pandemic threat to human health. A rapid vaccine production against fast outbreak is desired. We report, herein, a paradigm-shift influenza vaccine technology by presenting H5N1 hemagglutinin (HA) to the surface of yeast. We demonstrated, for the first time, that the HA surface-presented yeast can be used as influenza vaccines to elicit both humoral and cell-mediated immunity in mice. The HI titer of antisera reached up to 128 in vaccinated mice. A high level of H5N1 HA-specific IgG1 and IgG2a antibody production was detected after boost immunization. Furthermore, we demonstrated that the yeast surface-displayed HA preserves its antigenic sites. It preferentially binds to both avian- and human-type receptors. In addition, the vaccine exhibited high cross-reactivity to both homologous and heterologous H5N1 viruses. A high level production of anti-HA antibodies was detected in the mice five months after vaccination. Finally, our animal experimental results indicated that the yeast vaccine offered complete protection of mice from lethal H5N1 virus challenge. No severe side effect of yeast vaccines was noted in animal studies. This new technology allows for rapid and large-scale production of influenza vaccines for prepandemic preparation.