Cost and reimbursement of providing routine vaccines in outpatient obstetrician/gynecologist settings.

OBJECTIVE: To determine the costs and reimbursement associated with running a vaccine program in 5 obstetrics/gynecology practices in Colorado that had participated in a 3-year randomized, controlled trial focused on increasing vaccination in this setting. MATERIALS AND METHODS: This was a secondary analysis on costs from 5 clinics participating in a cluster-randomized controlled trial that assessed the effectiveness of a multimodal intervention to improve vaccination rates in outpatient obstetrics/gynecology clinics in central Colorado. The intervention included designation of an immunization champion within the practice, purchasing recommended vaccines for the practice, guidance on storage and management, implementing practices for routine identification of eligible patients for vaccination using the medical record, implementation of standing orders for vaccination, and vaccine administration to patients. Data on costs were gathered from office invoices, claims data, surveys and in-person observations during the course of the trial. These data incorporated supply and personnel costs for administering vaccines to individual patients that were derived from a combination of time-motion studies of staff and provider clinical activity, and practice reports, as well as costs related to maintaining the vaccination program at the practice level, which were derived from practice reports and invoices. Cost data for personnel time during visits in which vaccination was assessed and/or discussed, but no vaccine was given to the patient were also included in the main analysis. Data on practice revenue were derived from practice reimbursement records. All costs were described in 2014 dollars. The primary analysis was the proportion of costs for the program that were reimbursed, aggregated over all years of the study and combining all vaccines and practices, separated by obstetrics vs gynecology patients. RESULTS: Collectively the 5 clinics served >40,000 patient during the study period and served a population that was 16% Medicaid. Over the 3-year observation period, there were 6573 vaccination claims made collectively by the practices (4657 for obstetric patients, 1916 for gynecology patients). The most expensive component of the program was the material costs of the vaccines themselves, which ranged from a low of $9.67 for influenza vaccines, to a high of $141.40 for human papillomavirus vaccine. Staff costs for assessing and delivering vaccines during patient visits were minimal ($0.09-$1.24 per patient visit depending on the practice and whether an obstetrics or gynecology visit was being assessed) compared with staff costs for maintaining the program at a practice level (ie, assessing inventory, ordering and stocking vaccines; $0.89-$105.89 per vaccine dose given). When assessing all costs compared with all reimbursement, we found that vaccines for obstetrics patients were reimbursed at 159% of the costs over the study period, and for gynecology patients at 97% of the costs. Overall, the vaccination program was financially favorable across the practices, averaging 125% reimbursement of costs across the three study years. CONCLUSION: Providing routine vaccines to patients in the ambulatory obstetrics/gynecology setting is generally not financially prohibitive for practices, and may even be financially beneficial, though there is variability between practices that can affect the overall reimbursement margin.

Cost-effectiveness of adult vaccinations: A systematic review.

BACKGROUND: Coverage levels for many recommended adult vaccinations are low. The cost-effectiveness research literature on adult vaccinations has not been synthesized in recent years, which may contribute to low awareness of the value of adult vaccinations and to their under-utilization. We assessed research literature since 1980 to summarize economic evidence for adult vaccinations included on the adult immunization schedule. METHODS: We searched PubMed, EMBASE, EconLit, and Cochrane Library from 1980 to 2016 and identified economic evaluation or cost-effectiveness analysis for vaccinations targeting persons aged ≥18 years in the U.S. or Canada. After excluding records based on title and abstract reviews, the remaining publications had a full-text review from two independent reviewers, who extracted economic values that compared vaccination to "no vaccination" scenarios. RESULTS: The systematic searches yielded 1688 publications. After removing duplicates, off-topic publications, and publications without a "no vaccination" comparison, 78 publications were included in the final analysis (influenza = 25, pneumococcal = 18, human papillomavirus = 9, herpes zoster = 7, tetanus-diphtheria-pertussis = 9, hepatitis B = 9, and multiple vaccines = 1). Among outcomes assessing age-based vaccinations, the percent indicating cost-savings was 56% for influenza, 31% for pneumococcal, and 23% for tetanus-diphtheria-pertussis vaccinations. Among age-based vaccination outcomes reporting $/QALY, the percent of outcomes indicating a cost per QALY of ≤$100,000 was 100% for influenza, 100% for pneumococcal, 69% for human papillomavirus, 71% for herpes zoster, and 50% for tetanus-diphtheria-pertussis vaccinations. CONCLUSIONS: The majority of published studies report favorable cost-effectiveness profiles for adult vaccinations, which supports efforts to improve the implementation of adult vaccination recommendations.

Cost-utility of quadrivalent versus trivalent influenza vaccine in Brazil - comparison of outcomes from different static model types

ABSTRACT Background: Influenza burden in Brazil is considerable with 4.2-6.4 million cases in 2008 and influenza-like-illness responsible for 16.9% of hospitalizations. Cost-effectiveness of influenza vaccination may be assessed by different types of models, with limitations due to data availability, assumptions, and modelling approach. Objective: To understand the impact of model complexity, the cost-utility of quadrivalent versus trivalent influenza vaccines in Brazil was estimated using three distinct models: a 1-year decision tree population model with three age groups (FLOU); a more detailed 1-year population model with five age groups (FLORA); and a more complex lifetime multi-cohort Markov model with nine age groups (FLORENCE). Methods: Analysis 1 (impact of model structure) compared each model using the same data inputs (i.e., best available data for FLOU). Analysis 2 (impact of increasing granularity) compared each model populated with the best available data for that model. Results: Using the best data for each model, the discounted cost-utility ratio of quadrivalent versus trivalent influenza vaccine was R$20,428 with FLOU, R$22,768 with FLORA (versus R$20,428 in Analysis 1), and, R$19,257 with FLORENCE (versus R$22,490 in Analysis 1) using a lifetime horizon. Conceptual differences between FLORA and FLORENCE meant the same assumption regarding increased all-cause mortality in at-risk individuals had an opposite effect on the incremental cost-effectiveness ratio in Analysis 2 versus 1, and a proportionally higher number of vaccinated elderly in FLORENCE reduced this ratio in Analysis 2. Discussion: FLOU provided adequate cost-effectiveness estimates with data in broad age groups. FLORA increased insights (e.g., in healthy versus at-risk, paediatric, respiratory/non-respiratory complications). FLORENCE provided greater insights and precision (e.g., in elderly, costs and complications, lifetime cost-effectiveness). Conclusion: All three models predicted a cost per quality-adjusted life year gained for quadrivalent versus trivalent influenza vaccine in the range of R$19,257 (FLORENCE) to R$22,768 (FLORA) with the best available data in Brazil (Appendix A).

Structural-based designed modular capsomere comprising HA1 for low-cost poultry influenza vaccination.

Highly pathogenic avian influenza (HPAI) viruses cause a severe and lethal infection in domestic birds. The increasing number of HPAI outbreaks has demonstrated the lack of capabilities to control the rapid spread of avian influenza. Poultry vaccination has been shown to not only reduce the virus spread in animals but also reduce the virus transmission to humans, preventing potential pandemic development. However, existing vaccine technologies cannot respond to a new virus outbreak rapidly and at a cost and scale that is commercially viable for poultry vaccination. Here, we developed modular capsomere, subunits of virus-like particle, as a low-cost poultry influenza vaccine. Modified murine polyomavirus (MuPyV) VP1 capsomere was used to present structural-based influenza Hemagglutinin (HA1) antigen. Six constructs of modular capsomeres presenting three truncated versions of HA1 and two constructs of modular capsomeres presenting non-modified HA1 have been generated. These modular capsomeres were successfully produced in stable forms using Escherichia coli, without the need for protein refolding. Based on ELISA, this adjuvanted modular capsomere (CaptHA1-3C) induced strong antibody response (almost 105endpoint titre) when administered into chickens, similar to titres obtained in the group administered with insect cell-based HA1 proteins. Chickens that received adjuvanted CaptHA1-3C followed by challenge with HPAI virus were fully protected. The results presented here indicate that this platform for bacterially-produced modular capsomere could potentially translate into a rapid-response and low-cost vaccine manufacturing technology suitable for poultry vaccination.

Cost-effectiveness analysis of vaccinations and decision makings on vaccination programmes in Hong Kong: A systematic review.

OBJECTIVES: To describe and systematically review the modelling and reporting of cost-effectiveness analysis of vaccination in Hong Kong, and to identify areas for quality enhancement in future cost-effectiveness analyses. METHODS: We conducted a comprehensive and systematic review of cost-effectiveness studies related to vaccination and government immunisation programmes in Hong Kong published from 1990 to 2015, through database search of Pubmed, Web of Science, Embase, and OVID Medline. Methodological quality of selected studies was assessed using Consolidated Health Economic Evaluation Reporting Standards checklist (CHEERS). Decision making of vaccination was obtained from Scientific Committee on Vaccine Preventable Diseases (SCVPD) and Department of Health in Hong Kong. RESULTS: Nine eligible studies reporting twelve comparative cost-effectiveness comparisons of vaccination programme for influenza (n=2), pneumococcal disease (n=3), influenza plus pneumococcal disease (n=1), chickenpox (n=2), Haemophilus influenzae b (n=1), hepatitis A (n=1), cervical cancer (n=1) and rotavirus (n=1) were identified. Ten comparisons (83.3%) calculated the incremental cost-effectiveness ratio (ICER) of a vaccination strategy versus status quo as outcomes in terms of cost in USD per life-years, cost per quality-adjusted life-years, or cost per disability-adjusted life-years. Among those 10 comparisons in base-case scenario, 4 evaluated interventions were cost-saving relative to status quo while the ICER estimates in 3 of the 6 remaining comparisons were far below commonly accepted threshold and WHO willingness-to-pay threshold, suggestive of very cost-effective. Seven studies were of good quality based on the CHEERS checklist; one was of moderate quality; and one was of excellent quality. The common methodological problems were characterisation of heterogeneity and reporting of study parameters. CONCLUSIONS: There was a paucity of cost-effectiveness models evaluating vaccination targeted to the Hong Kong population. All evaluated vaccinations and immunisation interventions in Hong Kong, except for Haemophilus influenzae b, hepatitis A and HPV vaccinations, were considered either cost-saving or very cost-effective when compared to status quo.

Economic evaluation of pediatric influenza immunization program compared with other pediatric immunization programs: A systematic review.

This study compared the economic value of pediatric immunisation programmes for influenza to those for rotavirus (RV), meningococcal disease (MD), pneumococcal disease (PD), human papillomavirus (HPV), hepatitis B (Hep B), and varicella reported in recent (2000 onwards) cost-effectiveness (CE) studies identified in a systematic review of PubMed, health technology, and vaccination databases. The systematic review yielded 51 economic evaluation studies of pediatric immunisation - 10 (20%) for influenza and 41 (80%) for the other selected diseases. The quality of the eligible articles was assessed using Drummond's checklist. Although inherent challenges and limitations exist when comparing economic evaluations of immunisation programmes, an overall comparison of the included studies demonstrated cost-effectiveness/cost saving for influenza from a European-Union-Five (EU5) and United States (US) perspective; point estimates for cost/quality-adjusted life-years (QALY) from dominance (cost-saving with more effect) to ≤45,444 were reported. The economic value of influenza programmes was comparable to the other vaccines of interest, with cost/QALY in general considerably lower than RV, Hep B, MD and PD. Independent of the perspective and type of analysis, the economic impact of a pediatric influenza immunisation program was influenced by vaccine efficacy, immunisation coverage, costs, and most significantly by herd immunity. This review suggests that pediatric influenza immunisation may offer a cost effective strategy when compared with HPV and varicella and possibly more value compared with other childhood vaccines (RV, Hep B, MD and PD).

Expected cost effectiveness of high-dose trivalent influenza vaccine in US seniors.

OBJECTIVES: Seniors are particularly vulnerable to complications resulting from influenza infection. Numerous influenza vaccines are available to immunize US seniors, and practitioners must decide which product to use. Options include trivalent and quadrivalent standard-dose inactivated influenza vaccines (IIV3 and IIV4 respectively), as well as a high-dose IIV3 (HD). Our research examines the public health impact, budget impact, and cost-utility of HD versus IIV3 and IIV4 for immunization of US seniors 65 years of age and older. METHODS: Our model was based on US influenza-related health outcome data. Health care costs and vaccine prices were obtained from the Centers for Medicare and Medicaid Services. Efficacies of IIV3 and IIV4 were estimated from various meta-analyses of IIV3 efficacy. The results of a head-to-head randomized controlled trial of HD vs. IIV3 were used to estimate relative efficacy of HD. Conservatively, herd protection was not considered. RESULTS: Compared to IIV3, HD would avert 195,958 cases of influenza, 22,567 influenza-related hospitalizations, and 5423 influenza-related deaths among US seniors. HD generates 29,023 more Quality Adjusted Life Years (QALYs) and a net societal budget impact of $154 million. The Incremental Cost Effectiveness Ratio (ICER) for this comparison is $5299/QALY. 71% of the probabilistic sensitivity analysis (PSA) simulations were <$100,000/QALY. Compared to IIV4, HD would avert 169,257 cases of influenza, 21,222 hospitalizations and 5212 deaths. HD generates 27,718 more QALYs and a net societal budget impact of -$17 million and as such dominates IIV4. For this comparison, 81% of PSA simulations were <$100,000/QALY. CONCLUSIONS: HD is expected to achieve significant reductions in influenza-related morbidity and mortality. Further, HD is a cost effective alternative to both IIV3 and IIV4 in seniors. Our conclusions were robust in the face of sensitivity analyses.

"It's easier in pharmacy": why some patients prefer to pay for flu jabs rather than use the National Health Service.

BACKGROUND: There is a need to increase flu vaccination rates in England particularly among those under 65 years of age and at risk because of other conditions and treatments. Patients in at risk groups are eligible for free vaccination on the National Health Service (NHS) in England, but despite this, some choose to pay privately. This paper explores how prevalent this is and why people choose to do it. There is moderate to good evidence from several countries that community pharmacies can safely provide a range of vaccinations, largely seasonal influenza Immunisation. Pharmacy-based services can extend the reach of immunisation programmes. User, doctor and pharmacist satisfaction with these services is high. METHOD: Data were collected during the 2012-13 flu season as part of a community pharmacy private flu vaccination service to help identify whether patients were eligible to have their vaccination free of charge on the NHS. Additional data were collected from a sample of patients accessing the private service within 13 pharmacies to help identify the reasons patients paid when they were eligible for free vaccination. RESULTS: Data were captured from 89,011 privately paying patients across 479 pharmacies in England, of whom 6% were eligible to get the vaccination free. 921 patients completed a survey in the 13 pharmacies selected. Of these, 199 (22%) were eligible to get their flu vaccination for free. 131 (66%) were female. Average age was 54 years. Of the 199 patients who were eligible for free treatment, 100 (50%) had been contacted by their GP surgery to go for their vaccination, but had chosen not to go. Reasons given include accessibility, convenience and preference for pharmacy environment. CONCLUSIONS: While people at risk can access flu vaccinations free via the NHS, some choose to pay privately because they perceive that community pharmacy access is easier. There are opportunities for pharmacy to support the NHS in delivering free flu vaccinations to patients at risk by targeting people unlikely to access the service at GP surgeries.

Inovio.

A Pennsylvania company hopes to turn synthetic DNA vaccines into rapid response agents against flu epidemics and cancer.

Costo-efectividad de la vacunación contra influenza pandémica en mujeres embarazadas en Colombia / Cost-effectiveness of vaccinating pregnant women against pandemic influenza in Colombia

OBJETIVO: Estimar la relación costo-efectividad de la vacunación contra influenza pandémica A (H1N1) 2009 en mujeres embarazadas en Colombia durante la segunda onda de la pandemia. MÉTODOS: Se construyó un árbol de decisiones que simulaba los resultados sanitarios (muertes y años potenciales de vida perdidos, APVP) en dos cohortes de mujeres embarazadas, una vacunada y otra sin vacunar. Los parámetros del modelo fueron extraídos de la literatura científica y los costos se estimaron a partir de un estudio previo. Se calcularon razones de costo-efectividad incrementales (RCEI). RESULTADOS: La vacunación de embarazadas contra influenza pandémica habría evitado entre 4 664 y 15 741 consultas ambulatorias y entre 119 y 401 hospitalizaciones. Los costos de atención evitados serían de US$ 249 530 a US$ 842 163. Para el escenario base, vacunar embarazadas sería costo-efectivo (RCEI/APVP evitado US$ 7 657). Esta RCEI fue sensible a la letalidad de la enfermedad; en escenarios de baja letalidad la vacunación no sería costo-efectiva en Colombia. CONCLUSIONES: La vacunación en embarazadas contra influenza pandémica es costo-efectiva en un escenario de alta mortalidad. La evidencia existente de que las mujeres embarazadas tienen mayor riesgo de presentar complicaciones y de que la vacuna es segura justificaría su uso en embarazadas.

OBJECTIVE: Estimating the cost-effectiveness ratio of vaccinating pregnant women against the 2009 pandemic influenza A (H1N1) in Colombia during the second wave of the pandemic. METHODS: A decision tree was constructed, which simulated the health results (deaths and years of potential life lost [YPLL]) in two cohorts of pregnant women; one vaccinated, the other unvaccinated. The model's parameters were drawn from scientific literature and costs were estimated on the basis of a previous study. Incremental cost-effectiveness ratios (ICER) were calculated. RESULTS: Vaccinating pregnant women against pandemic flu would have prevented between 4 664 and 15 741 outpatient visits and between 119 and 401 hospitalizations. Between US$ 249 530 and US$ 842 163 in costs of care would have been avoided. For the base scenario, vaccinating pregnant women would be cost-effective (ICER/YPLL avoided US$ 7 657). This ICER was responsive to the disease's fatality rate; vaccina tion would not be cost-effective in Colombia in scenarios with a lower fatality rate. CONCLUSIONS: Vaccinating pregnant women against pandemic influenza is cost-effective in a scenario with a high mortality rate. The existing evidence that pregnant women are at increased risk of complications and that the vaccine is safe would justify its use in pregnant women.

Dendritic cell vaccines for the immunocompromised patient: prevention of influenza virus infection.

Prophylactic vaccination of cancer patients and recipients of hematopoietic stem cell transplant is generally a simple, efficient and cost-effective manner by which to prevent unnecessary infection and enhance overall clinical outcomes. However, some neoplastic conditions, particularly B-cell malignancies, impart a degree of immunosuppression that complicates traditional prophylactic approaches. Here, we make the case that the application of dendritic cell (DC) immunotherapy for the prophylaxis of infectious disease is both appropriate and cost effective for certain niche populations who are at risk of increased morbidity and who respond poorly to traditional vaccination, particularly influenza vaccination. Here we review the full spectrum of our preclinical work in this area, results demonstrating that DCs loaded with subunit recombinant hemagglutinin can generate robust hemagglutinin-specific immune responses both in vitro and in vivo. In vivo data indicated that a single injection of hemagglutinin-loaded DC was sufficient to generate high-titer antibody responses that could mediate protective immunity to lethal influenza virus challenge. The results suggest that DC immunotherapy for influenza prophylaxis is safe and feasible and that clinical studies might be warranted.

Cost-effectiveness of influenza immunization in adult cancer patients in Taiwan.

The aim of this study was to investigate the efficacy of the influenza vaccine among cancer patients in Taiwan. We determined the effect of immunization on the following outcomes of disease: hospitalizations, emergency department visits, hospital outpatient visits, physician office visits, and deaths. Cost-effectiveness was analysed from the perspectives of the healthcare system and society. A decision tree was used, with estimates of disease burden and costs based on data from published and unpublished sources. The model followed 34 112 cancer patients aged 20-64 years who were registered by the Taiwan National Cancer Registry in 2002. An influenza immunization programme for the cancer population would prevent 2555 cases of all types of influenza infection, 660 of which would be serious cases involving hospitalization, emergency department visits and death. From the perspective of the healthcare system, the programme would cost US$7.7 million, providing net savings of US$5.4 million. From a societal perspective, the programme would cost US$28.6 million, providing net savings of US$22.3 million. This corresponds to savings of US$2107 and US$6338 per case averted, from healthcare and societal perspectives, respectively, as well as 110 lives saved. Lesser disease burden, greater vaccine efficacy and lower cost of hospitalizations increased cost-effectiveness. Influenza immunization for cancer patients is cost-saving and cost-effective from a healthcare and societal perspective in Taiwan. We highly recommend annual influenza vaccinations for this patient group.

[Influenza vaccination coverage in France in 2007-2008: contribution of vaccination refund data from the general health insurance scheme]. / Taux de couverture vaccinale contre la grippe en France en 2007-2008: apport des données de remboursement du régime général.

INTRODUCTION: The French general health insurance scheme has implemented a national influenza vaccination program including full refund for those 65 years old or more and those under 65 years of age with a targeted chronic disease. OBJECTIVES: Our aim was to evaluate vaccination coverage (VC) according to sex, age, targeted chronic disease and geographical regions. METHODS: Data on vaccination refund for patients covered by the general health insurance scheme (85% of French population) was collected from the refund information system for the 2007-2008 campaign. RESULTS: Among the 11,618,719 targeted individuals, the overall VC was 51.5% (9.6% for individuals <10 years of age, 15.0% between 10 and 19, 28.1% between 20 and 64, and 63.3% for 65 individuals years of age or more). For those under 20 years of age, VC rates were inferior to 35% for targeted groups except for cystic fibrosis (67%). Among individuals 65 years of age or more, VC was 63.3%. The VC was 74.1% for people 65 years old or more with at least five refunds 6-months before vaccination (80% of the group) and for the others it was under 30%. The frequency of refund, vaccination for the 2006/2007 campaign, and having an attending physician were associated with an increased VC. CONCLUSION: Refund data is useful to determine and understand VC among target groups, to build specific strategies among those groups and to assess their impact. VC could be underestimated because some target individuals may be vaccinated through non-refundable procedures. Specific studies should improve the understanding of vaccination attitudes in targeted groups.

Costo efectividad de la vacunación contra influenza en menores de 2 años y mayores de 65 años en Colombia / Cost effectiveness of influenza vaccination in children under 2 years old and elderly in Colombia

Objetivo: Estimar la carga de enfermedad asociada a influenza y modelar el impacto epidemiológico y económico de la introducción de la vacuna para influenza en Colombia. Métodos: Se realizó un estudio de evaluación económica completa de la introducción de la vacuna de influenza en dos grupos poblacionales. Los desenlaces seleccionados en menores de dos años fueron la frecuencia de enfermedad respiratoria (ERA), consultas y hospitalizaciones por ERA. En mayores de 65 años se adicionaron las muertes y hospitalizaciones por enfermedad cardiosvascular y cerebrovascular. Resultados: En el escenario sin vacunación, el virus de influenza produciría anualmente 4 300 casos, 2 700 consultas, 900 hospitalizaciones y 230 muertes por ERA en menores de dos años. En mayores de 65 años, se presentarían anualmente 670 muertes por neumonía, 1 150 muertes por enfermedad cardiovascular y 720 muertes por enfermedad cerebrovascular relacionadas con influenza. El costo efectividad de la vacuna en menores de dos años oscila entre US $ 1 900 y US $ 2 967 por muerte evitada mientras que para mayores de 65 años la razón de costo efectividad seria costo ahorrativa. Conclusiones: Los resultados del presente estudio apoyarían la decisión del Ministerio de la Protección Social y algunas Secretarias de Salud de introducir la vacunación en Colombia para menores de dos años y mayores de 65 años.

Objective Estimating the burden of disease associated with influenza virus season and modelling the epidemiological and economic impacts of introducing an inactivated vaccine to Colombia. Methodology A complete economic evaluation was done in children aged less than 2 and adults aged over 65. The outcomes evaluated in the under 2-year olds included: the yearly number of cases of acute respiratory infection (ARI), medical visits, hospitalisations and deaths by ARI. The outcomes measured in adults were the number of yearly deaths and hospitalisations due to cardiocirculatory diseases (CCD). Results Influenza infection in children under 2 years old not having had vaccination may cause 4,300 cases, 2,700 medical visits, 900 hospitalisations and 230 deaths by ARI yearly. Amongst the elder group, influenza infection would be associated with 670 deaths by pneumonia and 1,870 deaths from CCD. The incremental cost effectiveness ratio (ICER) for flu vaccination among children under 2 ranged from USD$ 1,900 to USD$ 2,967 per averted death. ICER was cost saving in adults aged over 65. Conclusions This study's results supported the Colombian Ministry of Health's initiative for introducing yearly flu vaccination amongst small children and older adults in Colombia.

A study of pre-decision evaluation using influence diagram: an estimation of the benefits of influenza vaccination.

The purpose of this study is to develop a decision analysis model based on the influence diagram and estimate the benefits receiving of influenza vaccination. We collected more than 300,000 samples of elders aged over 65 years in Taiwan and then analyzed the health expenditure of the elders with and without influenza vaccination. We incorporate clinical results and the knowledge of physicians by an influence diagram. We divided our samples into four different age groups and the results showed that the total healthcare expenses for receiving influenza vaccination are more than the expenses for not receiving influenza vaccination for all age groups, we found there is a trend that the difference decreases if the age is older. We performed the one-way sensitivity analysis and Monde Carlo sensitivity analysis further and the results showed that the expected health expenditure is mostly sensitive to the hospitalization under the different condition.