Potential burden of universal influenza vaccination of young children on visits to primary care practices

OBJECTIVE

To estimate the additional number of visits to primary care practices that would be required to deliver universal influenza vaccination to 6- to 23-month-old children.

METHODS

Children who were covered by commercial and Medicaid managed care plans (70% of children in the region; >8000 children in each of 3 consecutive influenza seasons) in the 6-county region surrounding and including Rochester, New York, were studied. An analysis was conducted of insurance claims for visits (well-child care [WCC]; all other visits) to primary care practices during 3 consecutive influenza vaccination seasons (1998-2001). We determined the proportion of children who made 1 or 2 visits during the potential influenza vaccination period, simulating several possible lengths of time available for influenza vaccination (2, 3, 4, or 5 months). We measured the proportion of children who were vaccinated during each influenza vaccination period. The added visit burden was defined as the number of additional visits that would be required to vaccinate all children, simulating 2 scenarios: 1) administering influenza vaccination only during WCC visits and 2) considering all visits as opportunities for influenza vaccination.

RESULTS

Results were similar for each influenza season. Considering a 3-month influenza vaccination window and assuming that no opportunities were missed, if only WCC visits were used for influenza vaccination, then 74% of 6- to 23-month-olds would require at least 1 additional visit for vaccination--39% would require 1 additional visit and 35% would require 2 additional visits. If all visits to the practice were used for influenza vaccination during the 3-month window, then 46% would require at least 1 additional visit--34% would require 1 additional visit and 12% would require 2 additional visits. Longer vaccination periods would require fewer additional visits; eg, if a 4-month period were available, then 54% of children would require 1 or 2 additional visits if only WCC visits were used and 29% would require 1 or 2 additional visits if all visits were used for influenza vaccinations. Younger children (eg, 6- to 11-month-olds) would require fewer additional visits than older children (12- to 23-month-olds) because younger children already have more visits to primary care practices.

CONCLUSIONS

Implementation of universal influenza vaccination will result in a substantial increased burden to primary care practices in terms of additional visits for influenza vaccination. Practice-level strategies to minimize the additional burden include 1) using all visits (not just WCC visits) as opportunities for vaccination, 2) providing influenza vaccination for the maximum possible time period by starting to vaccinate as early as possible and continuing to vaccinate as late as possible, and 3) implementing short and efficient vaccination-only visits to accommodate the many additional visits to the practice.

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.

Influenza vaccination among healthy employees: a cost-benefit analysis

The cost of influenza vaccination and influenza infections was evaluated in a controlled study among healthy municipal homemakers. Acute respiratory infections were followed clinically and with laboratory samples for 8 months. Full follow-up was achieved in 351 persons in the intervention group, of whom 47% obtained vaccination, and 492 controls. Influenza infection was confirmed in 10 employees (8 of these in the control group) and other viral infections in 6 employees (5 of them controls). All infections occurred in non-vaccinated persons. The relative risk of infection in the control group was 2.9 (95% CI 0.6-13.4) for influenza and 3.1 (0.9-10.8) for all respiratory infections. The mean sick leave for influenza was 4.9 days. The cost per immunization was FIM 141, and the average cost per influenza infection FIM 1183. The cost per infection averted was FIM 6270, and the equivalent cost for immunization FIM 26.52. Influenza vaccination had a slight protective effect against both influenza and other respiratory infections. The cost of vaccination programmes exceeded the benefit from averted infections. Optimal vaccination strategies for healthy adults need to be planned individually with minimal loss of working time.

The cost-effectiveness of influenza vaccination for people aged 50 to 64 years: an international model

OBJECTIVES

Routine influenza vaccination is currently recommended in several countries for people aged more than 60 or 65 years or with high risk of complications. A lower age threshold of 50 years has been recommended in the United States since 1999. To help policymakers consider whether such a policy should be adopted more widely, we conducted an economic evaluation of lowering the age limit for routine influenza vaccination to 50 years in Brazil, France, Germany, and Italy.

METHODS

The probabilistic model was designed to compare in a single season the costs and clinical outcomes associated with two alternative vaccination policies for persons aged 50 to 64 years: reimbursement only for people at high risk of complications (current policy), and reimbursement for all individuals in this age group (proposed policy). Two perspectives were considered: third-party payer (TPP) and societal. Model inputs were obtained primarily from the published literature and validated through expert opinion. The historical distribution of annual influenza-like illness (ILI) incidence was used to simulate the uncertain incidence in any given season. We estimated gains in unadjusted and quality-adjusted life expectancy, and the cost per quality-adjusted life-year (QALY) gained. Deterministic and probabilistic sensitivity analyses were conducted.

RESULTS

Comparing the proposed to the current policy, the estimated mean costs per QALY gained were R$4,100, EURO 13,200, EURO 31,400 and EURO 15,700 for Brazil, France, Germany, and Italy, respectively, from a TPP perspective. From the societal perspective, the age-based policy is predicted to yield net cost savings in Germany and Italy, whereas the cost per QALY decreased to R$2800 for Brazil and EURO 8000 for France. The results were particularly sensitive to the ILI incidence rate, vaccine uptake, influenza fatality rate, and the costs of administering vaccination. Assuming a cost-effectiveness threshold ratio of EURO 50,000 per QALY gained, the probabilities of the new policy being cost-effective were 94% and 95% for France, 72% and near 100% for Germany, and 89% and 99% for Italy, from the TPP and societal perspectives, respectively.

CONCLUSIONS

Extending routine influenza vaccination to people more than 50 years of age is likely to be cost-effective in all four countries studied.

Values for preventing influenza-related morbidity and vaccine adverse events in children

Background

Influenza vaccination recently has been recommended for children 6–23 months old, but is not currently recommended for routine use in non-high-risk older children. Information on disease impact, costs, benefits, risks, and community preferences could help guide decisions about which age and risk groups should be vaccinated and strategies for improving coverage. The objective of this study was to measure preferences and willingness-to-pay for changes in health-related quality of life associated with uncomplicated influenza and two rarely-occurring vaccination-related adverse events (anaphylaxis and Guillain-Barré syndrome) in children.

Methods

We conducted telephone interviews with adult members selected at random from a large New England HMO (n = 112). Respondents were given descriptions of four health outcomes: uncomplicated influenza in a hypothetical 1-year-old child of their own, uncomplicated influenza in a hypothetical 14-year-old child of their own, anaphylaxis following vaccination, and Guillain-Barré syndrome. "Uncomplicated influenza" did not require a physician's visit or hospitalization. Preferences (values) for these health outcomes were measured using time-tradeoff and willingness-to-pay questions. Time-tradeoff questions asked the adult to assume they had a child and to consider how much time from the end of their own life they would be willing to surrender to avoid the health outcome in the child.

Results

Respondents said they would give a median of zero days of their lives to prevent an episode of uncomplicated influenza in either their (hypothetical) 1-year-old or 14-year-old, 30 days to prevent an episode of vaccination-related anaphylaxis, and 3 years to prevent a vaccination-related case of Guillain-Barré syndrome. Median willingness-to-pay to prevent uncomplicated influenza in a 1-year-old was $175, uncomplicated influenza in a 14-year-old was $100, anaphylaxis $400, and Guillain-Barré syndrome $4000. The median willingness-to-pay for an influenza vaccination for their children with no risk of anaphylaxis or Guillain-Barré syndrome was $50 and $100, respectively.

Conclusion

Most respondents said they would not be willing to trade any time from their own lives to prevent uncomplicated influenza in a child of their own, and the time traded did not vary by the age of the hypothetical affected child. However, adults did indicate a willingness-to-pay to prevent uncomplicated influenza in children, and that they would give more money to prevent the illness in a 1-year-old than in a 14-year-old. Respondents also indicated a willingness to pay a premium for a vaccine without any risk of severe complications.

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.

Cost-effectiveness of adjuvanted influenza vaccination of healthy children 6 to 60 months of age

This study estimated the health and economic outcomes of universal administration of a adjuvanted influenza vaccine to healthy preschool children, as compared with current immunization practice. A Markov model simulated a cohort of 3 million children and their households undergoing five influenza seasons. Assuming a vaccine uptake rate of 30%, at the current acquisition cost of Euro 5.50 per vaccine dose influenza vaccination (two doses for unprimed children) of 6- to 60-month- (5-year) old children averted more than 1 million clinical influenza episodes and saved Euro 63 million, from the perspective of the Italian society. From the perspective of the Italian health care service, influenza vaccination of 6- to 60- and of 6- to 24-month-old children cost Euro 10,000 and Euro 13,333 per quality-adjusted life year (QALY) saved, respectively. Administration of a adjuvanted influenza vaccine to children aged 6 to 60 months was highly cost-effective for the health care service and cost saving for the society.

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.

Technical report: Reduction of the influenza burden in children

Epidemiologic studies have shown that children of all ages with certain chronic conditions, such as asthma, and otherwise healthy children younger than 24 months (6 through 23 months) are hospitalized for influenza and its complications at high rates similar to those experienced by the elderly. Annual influenza immunization is already recommended for all children 6 months and older with high-risk conditions. By contrast, influenza immunization has not been recommended for healthy young children. To protect children against the complications of influenza, increased efforts are needed to identify and recall high-risk children. In addition, immunization of children between 6 through 23 months of age and their close contacts is now encouraged to the extent feasible. Children younger than 6 months may be protected by immunization of their household contacts and out-of-home caregivers. The ultimate goal is universal immunization of children 6 to 24 months of age. Issues that need to be addressed before institution of routine immunization of healthy young children include education of physicians and parents about the morbidity caused by influenza, adequate vaccine supply, and appropriate reimbursement of practitioners for influenza immunization. This report contains a summary of the influenza virus, protective immunity, disease burden in children, diagnosis, vaccines, and antiviral agents.

Cost effectiveness of influenza vaccination for healthy persons between ages 65 and 74 years

Healthy persons between 65 and 74 years of age represent a large proportion of the population in this age group. Internationally, there is a substantial variation in whether these people are included among the recommendations for routine influenza vaccination. We therefore conducted this study, updating an earlier analysis, to assess the health and economic benefits of routine influenza vaccination of healthy persons between 65 and 74 years of age. The health benefits associated with vaccination were estimated using the administrative data bases of a large HMO in the Minneapolis, St. Paul, Minnesota area. Multivariate models were used to estimate reductions in hospitalization and death associated with vaccination. The economic analysis took the societal perspective and presented the results as net cost or saving per 10,000 persons vaccinated and per death prevented. Direct and indirect monetary costs were included in the models and were estimated from the published literature. Monte Carlo simulation was used to conduct probabilistic sensitivity analysis in order to derive probability intervals for each estimate of net costs or savings. Over the six consecutive study seasons, 1990-1991 to 1995-1996, vaccination of healthy elderly person was associated with a 36% reduction in hospitalization for pneumonia or influenza (95% CI, 2-39%), an 18% reduction in hospitalization for all respiratory conditions (95% CI, -6 to 37%) and a 40% reduction in death (95% CI, 14-38%). Vaccination was also associated with cost savings in all scenarios evaluated. The findings of this study again affirm the value of an age-based strategy for routine influenza vaccination of all elderly persons including healthy elderly persons between 65 and 74 years.

Pharmacoeconomics of influenza vaccination for healthy working adults: reviewing the available evidence

A favourable pharmacoeconomic profile has been well established for influenza vaccination in the elderly. For employers relevant benefits seem to exist for vaccinating healthy working adults to avert absenteeism and related production losses. From a pharmacoeconomic point of view it is relevant to consider whether societal benefits of vaccination for healthy working adults is worthwhile given the costs of vaccination for the community. We searched Medline and Embase using the key words influenza (vaccination) in combination with cost, cost-benefit, cost-effectiveness, efficiency, economic evaluation, health-policy and pharmacoeconomics. From this primary search, we selected 11 studies concerned with the group of healthy working adults. We reviewed these studies according to several criteria: benefit-to-cost (B/C) ratio;vaccine effectiveness, influenza incidence, number of days of work absence due to illness; and relative cost of the vaccine. Three studies on vaccinating healthy working adults found costs exceeding the benefits (B/C-ratio <1). The remaining eight pharmacoeconomic studies found a B/C-ratio of almost two or more. Cost savings are strongly related to the inclusion of indirect benefits related to averted production losses. After exclusion of indirect costs and benefits of production gains/losses, only one of the eight studies remains cost saving. Considering the available pharmacoeconomic evidence, vaccination of healthy working adults in Western countries may be an intervention with favourable cost-effectiveness and cost-saving potentials if indirect benefits of averted production losses are included. Excluding indirect benefits and costs of production losses/gains, cost-saving potentials are limited. Recent international guidelines for pharmacoeconomic research advise the inclusion of production gains and losses in the preferred societal perspective. Hence, on the basis of the available evidence, influenza vaccination of healthy working adults may be recommended from pharmacoeconomic point of view. Pharmacoeconomics do, however, present only one argument for consideration aside from ethical issues, budgetary limits and psychosocial aspects.

Effectiveness of virosomal subunit influenza vaccine in preventing influenza-related illnesses and its social and economic consequences in children aged 3–14 years: A prospective cohort study

To evaluate the effectiveness of a virosomal subunit influenza vaccine in preventing influenza-related illnesses and its social and economic consequences in children aged 3-14 years, a prospective cohort study was carried out during the 2004-2005 influenza season in 11 private pediatric clinics in the Barcelona metropolitan area. One dose of a virosomal subunit inactivated influenza vaccine (Inflexal V Berna) was given during September and October 2004 to healthy children aged 3-14 years attended in 5 of the 11 clinics. Who comprised the vaccinated cohort (n=966). The non-vaccinated cohort (n=985) was comprised of children attended in the other six clinics. Informed consent was obtained from all parents. The follow up was performed between 1 November 2004 and 31 March 2005. Using a self-administered questionnaire, information was collected from parents or guardians on any type of acute, febrile respiratory illness suffered by their children during the study period, including antibiotic use, and absence from school or work-loss of parents as a result of the illness. RT-PCR (influenza A+B+C) was carried out on pharyngeal and nasal samples obtained from children attended by pediatricians during this period in these clinics with the following symptoms: fever> or =38.5 degrees lasting at least 72h, cough or sore throat (influenza-like illness). Adjusted vaccination effectiveness was 58.6% (95% CI 49.2-66.3) in preventing acute febrile respiratory illnesses, 75.1% (95% CI 61.0-84.1) in preventing cases of influenza-like illnesses and 88.4% (95% CI 49.2-97.3) in preventing laboratory-confirmed cases of influenza A. The adjusted vaccination effectiveness in reducing antibiotic use (18.6%, 95% CI -4.2 to 3.64), absence from school (57.8%, 95% CI 47.9-65.9) and work-loss of parents (33.3%, 95% CI 8.9-51.2) in children affected by an acute febrile respiratory illness was somewhat lower. Vaccination of children aged 3-14 years in pediatric practices with one dose of virosomal subunit inactivated influenza vaccine has the potential to considerably reduce the health and social burdens caused by influenza-related illnesses.

Influenza vaccines: a review and rationale for use in developed and underdeveloped countries

Multiple studies have demonstrated that influenza infection results in considerable morbidity and mortality, as well as other economic consequences, such as school and work absenteeism. Influenza vaccine has been shown to be both cost-effective and cost-saving. Despite this, the influenza vaccine appears to be under-utilized throughout the world, with significant variations both between countries and within countries over time. Data will be discussed that provide a rationale for the use of the influenza vaccine to protect the public health. Recommendations for the use of the influenza vaccine in various countries and guidelines for influenza vaccine use worldwide will be proposed.

Economic evaluation of influenza vaccination. Assessment for The Netherlands

OBJECTIVE

The objective of this study was to determine the costs associated with influenza and the cost effectiveness (net costs per life-year gained) of influenza vaccination in The Netherlands.

DESIGN AND SETTING

The economic evaluation comprised a cost-of-illness assessment and a cost-effectiveness analysis, both of which were conducted from the healthcare perspective in The Netherlands. The modelling framework for the economic evaluation linked epidemiological aspects of influenza (e.g. incidence, mortality, years of life lost) to vaccination coverage and healthcare resource use. Healthcare resource use was specified for hospitalisations, general practitioner visits and drugs.

INTERVENTION

The intervention assessed in the cost-effectiveness analysis was influenza vaccination.

MAIN OUTCOME MEASURES AND RESULTS

The costs of influenza were estimated to be 31 million euros (EUR) for the influenza season 1995/96 in The Netherlands (EUR1 approximately $US1.1). For the extended programme in 1997/98, i.e. all elderly people, the cost-effectiveness ratio was estimated at EUR1820 per life-year gained. Sub-group analysis demonstrated that the programme had a more favourable cost effectiveness among the chronically ill elderly population (cost saving) than among the rest of the elderly population (EUR6900 per life-year gained).

CONCLUSION

Influenza vaccination has a cost-effectiveness ratio that is better than or comparable to that of other implemented Dutch programmes in the prevention of infectious diseases.

French economic evaluations of influenza and influenza vaccination

The cost-of-illness studies of influenza performed in France or the years 1985 and 1989 have shown that the major economic consideration in the respective sizes of indirect and direct costs. Depending on the point of view (from the perspective of National Health Insurance or the societal perspective) and the method used for measuring indirect costs, it was estimated that they could be between 1.5 and 9 times higher than direct costs. A cost-benefit study of influenza vaccination for the employed adult population showed that vaccination is a cost-saving strategy, although this was also contingent upon the problems associated with measuring indirect benefits as well as the effectiveness rate of vaccination in real conditions.

Mean-field analysis of an inductive reasoning game: application to influenza vaccination

Recently we have introduced an inductive reasoning game of voluntary yearly vaccination to establish whether or not a population of individuals acting in their own self-interest would be able to prevent influenza epidemics. Here, we analyze our model to describe the dynamics of the collective yearly vaccination uptake. We discuss the mean-field equations of our model and first order effects of fluctuations. We explain why our model predicts that severe epidemics are periodically expected even without the introduction of pandemic strains. We find that fluctuations in the collective yearly vaccination uptake induce severe epidemics with an expected periodicity that depends on the number of independent decision makers in the population. The mean-field dynamics also reveal that there are conditions for which the dynamics become robust to the fluctuations. However, the transition between fluctuation-sensitive and fluctuation-robust dynamics occurs for biologically implausible parameters. We also analyze our model when incentive-based vaccination programs are offered. When a family-based incentive is offered, the expected periodicity of severe epidemics is increased. This results from the fact that the number of independent decision makers is reduced, increasing the effect of the fluctuations. However, incentives based on the number of years of prepayment of vaccination may yield fluctuation-robust dynamics where severe epidemics are prevented. In this case, depending on prepayment, the transition between fluctuation-sensitive and fluctuation-robust dynamics may occur for biologically plausible parameters. Our analysis provides a practical method for identifying how many years of free vaccination should be provided in order to successfully ameliorate influenza epidemics.

Parents' preferences for seasonal influenza vaccine for their children in Japan

In Japan, trivalent inactivated influenza vaccine is the only approved influenza vaccine. It is typically administrated by hypodermic injection, and children under 13 years of age are recommended to be vaccinated two times during each winter season. Live-attenuated influenza vaccine (LAIV) is administered by a thimerosal-free nasal spray. If LAIV is approved in the future in Japan, parents will have an alternative type of influenza vaccine for their children. This study investigated parents' preference for the type of seasonal influenza vaccine for their children if alternatives are available. The marginal willingness to pay for vaccine benefits was also evaluated. We conducted a discrete choice experiment, a quantitative approach that is often used in healthcare studies, in January 2013. Respondents were recruited from a registered online survey panel, and parents with at least one child under 13 years of age were offered questionnaires. This study showed that for seasonal influenza vaccines for their children, parents are more likely to value safety, including thimerosal-free vaccines and those with a lower risk of adverse events, instead of avoiding the momentary pain from an injection. If LAIV is released in Japan, the fact that it is thimerosal-free could be an advantage. However, for parents to choose LAIV, they would need to accept the slightly higher risk of minor adverse events from LAIV.

Physician Attitudes Toward Adult Vaccines and Other Preventive Practices, United States, 2012

OBJECTIVES

We described the following among U.S. primary care physicians: (1) perceived importance of vaccines recommended by the Advisory Committee on Immunization Practices relative to U.S. Preventive Services Task Force (USPSTF) preventive services, (2) attitudes toward the U.S. adult immunization schedule, and (3) awareness and use of Medicare preventive service visits.

METHODS

We conducted an Internet and mail survey from March to June 2012 among national networks of general internists and family physicians.

RESULTS

We received responses from 352 of 445 (79%) general internists and 255 of 409 (62%) family physicians. For a 67-year-old hypothetical patient, 540/606 (89%, 95% confidence interval [CI] 87, 92) of physicians ranked seasonal influenza vaccine and 487/607 (80%, 95% CI 77, 83) ranked pneumococcal vaccine as very important, whereas 381/604 (63%, 95% CI 59, 67) ranked Tdap/Td vaccine and 288/607 (47%, 95% CI 43, 51) ranked herpes zoster vaccine as very important (p<0.001). All Grade A USPSTF recommendations were considered more important than Tdap/Td and herpes zoster vaccines. For the hypothetical patient aged 30 years, the number and percentage of physicians who reported that the Tdap/Td vaccine (377/604; 62%, 95% CI 59, 66) is very important was greater than the number and percentage who reported that the seasonal influenza vaccine (263/605; 43%, 95% CI 40, 47) is very important (p<0.001), and all Grade A and Grade B USPSTF recommendations were more often reported as very important than was any vaccine. A total of 172 of 587 physicians (29%) found aspects of the adult immunization schedule confusing. Among physicians aware of "Welcome to Medicare" and annual wellness visits, 492/514 (96%, 95% CI 94, 97) and 329/496 (66%, 95% CI 62, 70), respectively, reported having conducted fewer than 10 such visits in the previous month.

CONCLUSIONS

Despite lack of prioritization of vaccines by ACIP, physicians are prioritizing some vaccines over others and ranking some vaccines below other preventive services. These attitudes and confusion about the immunization schedule may result in missed opportunities for vaccination. Medicare preventive visits are not being used widely despite offering a venue for delivery of preventive services, including vaccinations.

Influenza vaccination guidelines and vaccine sales in southeast Asia: 2008-2011

BACKGROUND

Southeast Asia is a region with great potential for the emergence of a pandemic influenza virus. Global efforts to improve influenza surveillance in this region have documented the burden and seasonality of influenza viruses and have informed influenza prevention strategies, but little information exists about influenza vaccination guidelines and vaccine sales.

METHODS

To ascertain the existence of influenza vaccine guidelines and define the scope of vaccine sales, we sent a standard three-page questionnaire to the ten member nations of the Association of Southeast Asian Nations. We also surveyed three multinational manufacturers who supply influenza vaccines in the region.

RESULTS

Vaccine sales in the private sector were <1000 per 100,000 population in the 10 countries. Five countries reported purchasing vaccine for use in the public sector. In 2011, Thailand had the highest combined reported rate of vaccine sales (10,333 per 100,000). In the 10 countries combined, the rate of private sector sales during 2010-2011 (after the A(H1N1)2009pdm pandemic) exceeded 2008 pre-pandemic levels. Five countries (Indonesia, Malaysia, Singapore, Thailand and Vietnam) had guidelines for influenza vaccination but only two were consistent with global guidelines. Four recommended vaccination for health care workers, four for elderly persons, three for young children, three for persons with underlying disease, and two for pregnant women.

CONCLUSIONS

The rate of vaccine sales in Southeast Asia remains low, but there was a positive impact in sales after the A(H1N1)2009pdm pandemic. Low adherence to global vaccine guidelines suggests that more work is needed in the policy arena.

Economics of employer-sponsored workplace vaccination to prevent pandemic and seasonal influenza

Employers may be loath to fund vaccination programs without understanding the economic consequences. We developed a decision analytic computational simulation model including dynamic transmission elements that estimated the cost-benefit of employer-sponsored workplace vaccination from the employer's perspective. Implementing such programs was relatively inexpensive (<$35/vaccinated employee) and, in many cases, cost saving across diverse occupational groups in all seasonal influenza scenarios. Such programs were cost-saving for a 20% serologic attack rate pandemic scenario (range: -$15 to -$995) per vaccinated employee) and a 30% serologic attack rate pandemic scenario (range: -$39 to -$1,494 per vaccinated employee) across all age and major occupational groups.

Effectiveness and cost-effectiveness of vaccination against pandemic influenza (H1N1) 2009

BACKGROUND

Decisions on the timing and extent of vaccination against pandemic (H1N1) 2009 virus are complex.

OBJECTIVE

To estimate the effectiveness and cost-effectiveness of pandemic influenza (H1N1) vaccination under different scenarios in October or November 2009.

DESIGN

Compartmental epidemic model in conjunction with a Markov model of disease progression.

DATA SOURCES

Literature and expert opinion.

TARGET POPULATION

Residents of a major U.S. metropolitan city with a population of 8.3 million.

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal.

INTERVENTIONS

Vaccination in mid-October or mid-November 2009.

OUTCOME MEASURES

Infections and deaths averted, costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness.

RESULTS OF BASE-CASE ANALYSIS

Assuming each primary infection causes 1.5 secondary infections, vaccinating 40% of the population in October or November would be cost-saving. Vaccination in October would avert 2051 deaths, gain 69 679 QALYs, and save $469 million compared with no vaccination; vaccination in November would avert 1468 deaths, gain 49 422 QALYs, and save $302 million.

RESULTS OF SENSITIVITY ANALYSIS

Vaccination is even more cost-saving if longer incubation periods, lower rates of infectiousness, or increased implementation of nonpharmaceutical interventions delay time to the peak of the pandemic. Vaccination saves fewer lives and is less cost-effective if the epidemic peaks earlier than mid-October.

LIMITATIONS

The model assumed homogenous mixing of case-patients and contacts; heterogeneous mixing would result in faster initial spread, followed by slower spread. Additional costs and savings not included in the model would make vaccination more cost-saving.

CONCLUSION

Earlier vaccination against pandemic (H1N1) 2009 prevents more deaths and is more cost-saving. Complete population coverage is not necessary to reduce the viral reproductive rate sufficiently to help shorten the pandemic.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality and National Institute on Drug Abuse.

Key issues for estimating the impact and cost-effectiveness of seasonal influenza vaccination strategies

Many countries have considered or are considering modifying their seasonal influenza immunization policies. Estimating the impact of such changes requires understanding the existing clinical and economic burden of influenza, as well as the potential impact of different vaccination options. Previous studies suggest that vaccinating clinical risk groups, health care workers, children and the elderly may be cost-effective. However, challenges in such estimation include: (1) potential cases are not usually virologically tested; (2) cases have non-specific symptoms and are rarely reported to surveillance systems; (3) endpoints for influenza proxies (such as influenza-like illness) need to be matched to case definitions for treatment costs, (4) disease burden estimates vary from year to year with strain transmissibility, virulence and prior immunity, (5) methods to estimate productivity losses due to influenza vary, (6) vaccine efficacy estimates from trials differ due to variation in subtype prevalence, vaccine match and case ascertainment, and (7) indirect (herd) protection from vaccination depends on setting-specific variables that are difficult to directly measure. Given the importance of knowing the impact of changes to influenza policy, such complexities need careful treatment using tools such as population-based trial designs, meta-analyses, time-series analyses and transmission dynamic models.

Cost-effectiveness of 2009 pandemic influenza A(H1N1) vaccination in the United States

BACKGROUND

Pandemic influenza A(H1N1) (pH1N1) was first identified in North America in April 2009. Vaccination against pH1N1 commenced in the U.S. in October 2009 and continued through January 2010. The objective of this study was to evaluate the cost-effectiveness of pH1N1 vaccination.

METHODOLOGY

A computer simulation model was developed to predict costs and health outcomes for a pH1N1 vaccination program using inactivated vaccine compared to no vaccination. Probabilities, costs and quality-of-life weights were derived from emerging primary data on pH1N1 infections in the US, published and unpublished data for seasonal and pH1N1 illnesses, supplemented by expert opinion. The modeled target population included hypothetical cohorts of persons aged 6 months and older stratified by age and risk. The analysis used a one-year time horizon for most endpoints but also includes longer-term costs and consequences of long-term sequelae deaths. A societal perspective was used. Indirect effects (i.e., herd effects) were not included in the primary analysis. The main endpoint was the incremental cost-effectiveness ratio in dollars per quality-adjusted life year (QALY) gained. Sensitivity analyses were conducted.

RESULTS

For vaccination initiated prior to the outbreak, pH1N1 vaccination was cost-saving for persons 6 months to 64 years under many assumptions. For those without high risk conditions, incremental cost-effectiveness ratios ranged from $8,000-$52,000/QALY depending on age and risk status. Results were sensitive to the number of vaccine doses needed, costs of vaccination, illness rates, and timing of vaccine delivery.

CONCLUSIONS

Vaccination for pH1N1 for children and working-age adults is cost-effective compared to other preventive health interventions under a wide range of scenarios. The economic evidence was consistent with target recommendations that were in place for pH1N1 vaccination. We also found that the delays in vaccine availability had a substantial impact on the cost-effectiveness of vaccination.