Influenza vaccination programs for elderly persons: cost-effectiveness in a health maintenance organization

Effect of influenza vaccine subsidies for older adults on vaccination coverage and mortality before and during the COVID-19 pandemic: an ecological study in Japan

OBJECTIVE

We aimed to determine how municipal subsidies for seasonal influenza vaccines for the elderly affected vaccination coverage and health outcomes and how responses to vaccine prices changed during the COVID-19 pandemic.

STUDY DESIGN AND METHODS

This ecological study includes 1245 municipalities in Japan between 2019 and 2020. Fixed-effects regression analysis was performed to evaluate the effect of influenza vaccine cost subsidy for people aged 65 years or older on vaccination coverage, all-cause mortality, and influenza-related mortality.

RESULTS

The vaccination rate increased when patients' copayments decreased, and reducing the copayment by 1000 Japanese Yen (JPY) was estimated to increase the vaccination rate by 6.3% (95% confidence interval [CI] 4.5-8.2%) in the adjusted model. When examining the additional effect of a zero price compared to a nearly zero price, we found that a zero price increased the immunization rate by 6.4% (95% CI 1.4-11.5%). The effect of copayment on the increase in vaccination coverage was significantly lower during the pandemic than in the pre-pandemic period. The municipal and prefectural analyses found no association between influenza vaccine copayments and all-cause, influenza, or pneumonia mortality.

CONCLUSION

Cost subsidies and the zero-price effect were shown to increase vaccination coverage but were not associated with relevant mortality measures. Although the impact was attenuated under pandemic conditions, cost subsidy effectively increases the vaccination rate.

Antivax attitude in the general population along the autism-schizophrenia continuum and the impact of socio-demographic factors

Introduction

One of the most important inventions in human history is vaccines. However, to date a consistent amount of people exhibit a hesitant approach toward them and mixed results have emerged in the attempt to characterize which factors may play a role in predicting such negative attitude. Here, we aimed at investigating how the individual scoring along the autism-schizophrenic continuum component and socio-cultural factors contribute toward vaccination attitudes in the general population.

Methods

To test whether individual position along the autism-schizophrenic continuum could predict vaccine attitude, we used principal component analysis (PCA) to extract the component showing diametric loading between the Schizotypal Personality Questionnaire (SPQ) and Autistic Quotient (AQ) subscales. Then, we performed a series of multiple linear regression analyses to understand the relation between the ASD-SSD continuum component and Vax scores. We also included socio-demographic factors (i.e., gender, education level, and age) as predictors.

Results

Multiple regression analysis revealed that the closer the individual lied on the positive schizotypal pole, the higher was their negative attitude toward vaccines. A diametric, more favorable disposition was found for individuals closer to the autistic end of the continuum. Furthermore, we reported that among the socio-cultural factors, only age can be considered a significant predictor of vaccination attitudes, with younger participants showing a more positive attitudes toward vaccination, while the level of education is an important protective factor in mitigating the negative impact that the proximity to the SSD pole and age play against vaccination disposition.

Discussion

These findings are relevant to improve targeted public health interventions, highlighting the crucial role of demographic, psychological, and social correlates in predicting anti-vax beliefs, which have the devasting potential to increase the spread of infectious disease.

Endoplasmic reticulum stress response and bile acid signatures associate with multi-strain seroresponsiveness during elderly influenza vaccination

The elderly are an important target for influenza vaccination, and the determination of factors that underlie immune responsiveness is clinically valuable. We evaluated the immune and metabolic profiles of 205 elderly Singaporeans administered with Vaxigrip. Despite high seroprotection rates, we observed heterogeneity in the response. We stratified the cohort into complete (CR) or incomplete responders (IR), where IR exhibited signs of accelerated T cell aging. We found a higher upregulation of genes associated with the B-cell endoplasmic-reticulum stress response in CR, where XBP-1 acts as a key upstream regulator. B-cells from IR were incapable of matching the level of XBP-1 upregulation observed in CR after inducing ER stress with tunicamycin in vitro. Metabolic signatures also distinguished CR and IR - as CR presented with a greater diversity of bile acids. Our findings suggest that the ER-stress pathway activation could improve influenza vaccination in the elderly.

Influenza Vaccination for the Prevention of Cardiovascular Disease in the Americas: Consensus document of the Inter-American Society of Cardiology and the Word Heart Federation

Background

Cardiovascular mortality is decreasing but remains the leading cause of death world-wide. Respiratory infections such as influenza significantly contribute to morbidity and mortality in patients with cardiovascular disease. Despite of proven benefits, influenza vaccination is not fully implemented, especially in Latin America.

Objective

The aim was to develop a regional consensus with recommendations regarding influenza vaccination and cardiovascular disease.

Methods

A multidisciplinary team composed by experts in the management and prevention of cardiovascular disease from the Americas, convened by the Inter-American Society of Cardiology (IASC) and the World Heart Federation (WHF), participated in the process and the formulation of statements. The modified RAND/UCLA methodology was used. This document was supported by a grant from the WHF.

Results

An extensive literature search was divided into seven questions, and a total of 23 conclusions and 29 recommendations were achieved. There was no disagreement among experts in the conclusions or recommendations.

Conclusions

There is a strong correlation between influenza and cardiovascular events. Influenza vaccination is not only safe and a proven strategy to reduce cardiovascular events, but it is also cost saving. We found several barriers for its global implementation and potential strategies to overcome them.

Seasonal Influenza and Low Flu Vaccination Coverage as Important Factors Modifying the Costs and Availability of Hospital Services in Poland: A Retrospective Comparative Study

Introduction: Influenza infection is associated with potential serious complications, increased hospitalization rates, and a higher risk of death. Materials and Methods: A retrospective comparative analysis of selected indicators of hospitalization from the University Hospital in Wroclaw, Poland, was carried out on patients with confirmed influenza infection in comparison to a control group randomly selected from among all other patients hospitalized on the respective wards during the 2018-2019 influenza season. Results: The mean laboratory testing costs for the entire hospital were 3.74-fold higher and the mean imaging test costs were 4.02-fold higher for patients with confirmed influenza than for the control group; the hospital expenses were additionally raised by the cost of antiviral therapy, which is striking when compared against the cost of a single flu vaccine. During the 2018-2019 influenza season, influenza infections among the hospital patients temporarily limited the healthcare service availability in the institution, which resulted in reduced admission rates to the departments related to internal medicine; the mean absence among the hospital staff totaled approximately 7 h per employee, despite 7.3% of the staff having been vaccinated against influenza at the hospital's expense. Conclusions: There were significant differences in the hospitalization indicators between the patients with confirmed influenza and the control group, which markedly increased the hospital care costs in this multi-specialty university hospital.

A Framework for Discovering Health Disparities among Cohorts in an Influenza Epidemic

Infectious diseases such as Influenza and Ebola pose a serious threat to everyone but certain demographics and cohorts face a higher risk of infection than others. This research provides a computational framework for studying health disparities among cohorts based on individual level features, such as age, gender, income, etc. We apply this framework to find health disparities among subpopulations in an influenza epidemic and evaluate vaccination prioritization strategies to achieve specific objectives. We explore the heterogeneities in individuals' demographic and socioeconomic attributes as the potential cause of health disparities. An agent-based model is used to simulate an influenza epidemic over a synthetic social contact network of the Montgomery County in Southwest Virginia to identify infected cases which are then labeled with a specific clinical outcome by using a predefined probability distribution based on age and risk level. We divide the population into age and income based cohorts and measure the direct and indirect economic impact of vaccination for each cohort. Simulation-based results find strong health disparities across age and income groups. Various vaccine distribution strategies are considered and outcomes are measured through metrics such as death count, total number of infections, net return per capita, net return per dollar spent and net return per vaccinated person. The results, framework, and methodology developed here can assist public health policy makers in efficiently allocating limited pharmaceutical resources.

Influenza vaccine: A viable option to protect pregnant women and infants from seasonal flu: A retrospective hospital-based study in India

BACKGROUND

Influenza is a highly contagious disease with global annual outbreaks of 3-5 million severe cases and 0.25-0.5 million deaths. The risk is greater in pregnant women that results in high morbidity and mortality.

OBJECTIVE

The objective of this study was to see the efficacy of influenza vaccine on pregnant women and their newborn upto 6 months.

METHOD

This was a retrospective study (January 2016-March 2018). Records of 346 pregnant women were included in this study (vaccinated: 288; unvaccinated: 58). Women and infants were categorised into Category A, B or C according to the guidelines issued by the Ministry of Health and Family Welfare, India on influenza.

RESULTS

The groups were comparable with respect to baseline characteristics. Greater number of women received influenza vaccine during the first trimester (n = 117). During the gestation period, majority of the women in the vaccinated group were symptom-free compared with the unvaccinated (92% vs 70.7%). Also, none of the vaccinated women were categorised into category C compared with one who was laboratory tested positive for influenza in the unvaccinated group. Similar results were seen postpartum and more number of infants remained symptom-free in the vaccinated group compared with unvaccinated (69.3% vs 25.9%). More number of infants were born pre-term in the unvaccinated group compared with vaccinated (15.5% vs 8.6%).

CONCLUSIONS

Immunisation with influenza vaccine in any trimester during pregnancy was found to protect the mother and infants upto 6 months of age against seasonal influenza without significant maternal adverse effects. In order to improve vaccination rates, there must be a national vaccination policy and incorporation of maternal immunisation in standard antenatal care.

Cost-effectiveness of increased influenza vaccination uptake against readmissions of major adverse cardiac events in the US

Background

Although influenza vaccination has been shown to reduce the incidence of major adverse cardiac events (MACE) among those with existing cardiovascular disease (CVD), in the 2015–16 season, coverage for persons with heart disease was only 48% in the US.

Methods

We built a Monte Carlo (probabilistic) spreadsheet-based decision tree in 2018 to estimate the cost-effectiveness of increased influenza vaccination to prevent MACE readmissions. We based our model on current US influenza vaccination coverage of the estimated 493,750 US acute coronary syndrome (ACS) patients from the healthcare payer perspective. We excluded outpatient costs and time lost from work and included only hospitalization and vaccination costs. We also estimated the incremental cost/MACE case averted and incremental cost/QALY gained (ICER) if 75% hospitalized ACS patients were vaccinated by discharge and estimated the impact of increasing vaccination coverage incrementally by 5% up to 95% in a sensitivity analysis, among hospitalized adults aged ≥ 65 years and 18–64 years, and varying vaccine effectiveness from 30–40%.

Result

At 75% vaccination coverage by discharge, vaccination was cost-saving from the healthcare payer perspective in adults ≥ 65 years and the ICER was $12,680/QALY (95% CI: 6,273–20,264) in adults 18–64 years and $2,400 (95% CI: -1,992–7,398) in all adults 18 + years. These resulted in ~ 500 (95% CI: 439–625) additional averted MACEs/year for all adult patients aged ≥18 years and added ~700 (95% CI: 578–825) QALYs. In the sensitivity analysis, vaccination becomes cost-saving in adults 18+years after about 80% vaccination rate. To achieve 75% vaccination rate in all adults aged ≥ 18 years will require an additional cost of $3 million. The effectiveness of the vaccine, cost of vaccination, and vaccination coverage rate had the most impact on the results.

Conclusion

Increasing vaccination rate among hospitalized ACS patients has a favorable cost-effectiveness profile and becomes cost-saving when at least 80% are vaccinated.

Rocking Pneumonia and the Boogie Woogie Flu

The relation between pneumonia and influenza is regularly addressed in modern music. Epidemiological data obtained during influenza pandemics, as well as during seasonal influenza, illustrate and underscore this association. Even though the number of pneumonia cases are generally under-reported and blood tests show a lack of sensitivity, a clear link between influenza and pneumonia can still be observed. In fact, the majority of mortality during influenza pandemics is due to pneumonia caused by a bacterial superinfection, in most cases Streptococcus pneumoniae. Vaccination is a powerful tool to prevent the development of both influenza and pneumonia in children, as well as in the elderly. Cellular and molecular data show that influenza can lead to changes in the integrity of lung epithelial cells, including desialysation of carbohydrate moieties, which favour attachment and invasion of S. pneumoniae. Further elucidation of these mechanisms could lead to targeted intervention strategies, in which universal influenza vaccines could play a role.

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.

Impact of weather factors on influenza hospitalization across different age groups in subtropical Hong Kong

Accumulating evidence demonstrates the significant influence of weather factors, especially temperature and humidity, on influenza seasonality. However, it is still unclear whether temperature variation within the same day, that is diurnal temperature range (DTR), is related to influenza seasonality. In addition, the different effects of weather factors on influenza seasonality across age groups have not been well documented in previous studies. Our study aims to explore the effects of DTR and humidity on influenza seasonality, and the differences in the association between weather factors and influenza seasonality among different age groups in Hong Kong, China. Generalized additive models were conducted to flexibly assess the impact of DTR, absolute humidity (vapor pressure, VP), and relative humidity on influenza seasonality in Hong Kong, China, from January 2012 to December 2016. Stratified analyses were performed to determine if the effects of weather factors differ across age groups (< 5, 5-9, 10-64, and > 64 years). The results suggested that DTR, absolute humidity, and relative humidity were significantly related to influenza seasonality in dry period (when VP is less than 20 mb), while no significant association was found in humid period (when VP is greater than 20 mb). The percentage changes of hospitalization rates due to influenza associated with per unit increase of weather factors in the very young children (age 0-4) and the elderly (age 65+) were higher than that in the adults (age 10-64). Diurnal temperature range is significantly associated with influenza seasonality in dry period, and the effects of weather factors differ across age groups in Hong Kong, China.

Basic principle of population-based cohort study to evaluate influenza vaccine effectiveness among elderly Japanese

Influenza vaccines minimize the risk of influenza-related morbidity, complication, and death in elderly people. Although evaluating vaccine effectiveness (VE) is important for promoting immunization programs and coping with influenza epidemics, it is difficult to evaluate its effectiveness in Japan, where no frameworks to use large databases, such as a vaccination registry and health maintenance organization datasets, are available. Therefore, another analytic epidemiological investigations to evaluate VE in Japan are required. Herein, we describe the basic principles of a cohort study, which might be the most comprehensive, but expensive, study design. It is particularly important to be aware of the potential bias and confounding factors that should be minimized in the study design and analysis. We focus on "laboratory-confirmed influenza" and "influenza-like illness", and discuss why it is important to follow up with equal intensity, and how to control for bias; problems that often arise in population-based observational cohort studies.

Effects of influenza immunization on pneumonia in the elderly

Influenza virus is a common pathogen implicated in respiratory tract infections, annually affecting up to 20% of the general population, and pneumonia is a leading cause of death after influenza infection. Post-influenza pneumonia is especially common in the elderly and chronically ill patients. The risk of post-influenza pneumonia is significantly increased according to the number of concurrent comorbidities. Vaccination is the primary measure used to abate influenza epidemics and associated complications. In meta-analyses, influenza vaccine significantly reduces pneumonia- and influenza-related hospitalizations, with a vaccine effectiveness of 25-53%. However, considering the poor effectiveness of conventional influenza vaccines in the elderly, several highly immunogenic influenza vaccines have been developed. Further evaluations of the comparative effectiveness of diverse vaccine formulations are warranted to assess their utility for preventing influenza infection, post-influenza pneumonia, and related hospitalization/mortality. Based on cost-effectiveness and budget impact analysis, influenza vaccination strategies should be tailored in the elderly.

Vaccines for preventing influenza in the elderly

BACKGROUND

The consequences of influenza in the elderly (those age 65 years or older) are complications, hospitalisations, and death. The primary goal of influenza vaccination in the elderly is to reduce the risk of death among people who are most vulnerable. This is an update of a review published in 2010. Future updates of this review will be made only when new trials or vaccines become available. Observational data included in previous versions of the review have been retained for historical reasons but have not been updated because of their lack of influence on the review conclusions.

OBJECTIVES

To assess the effects (efficacy, effectiveness, and harm) of vaccines against influenza in the elderly.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 11), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register; MEDLINE (1966 to 31 December 2016); Embase (1974 to 31 December 2016); Web of Science (1974 to 31 December 2016); CINAHL (1981 to 31 December 2016); LILACS (1982 to 31 December 2016); WHO International Clinical Trials Registry Platform (ICTRP; 1 July 2017); and ClinicalTrials.gov (1 July 2017).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs assessing efficacy against influenza (laboratory-confirmed cases) or effectiveness against influenza-like illness (ILI) or safety. We considered any influenza vaccine given independently, in any dose, preparation, or time schedule, compared with placebo or with no intervention. Previous versions of this review included 67 cohort and case-control studies. The searches for these trial designs are no longer updated.

DATA COLLECTION AND ANALYSIS

Review authors independently assessed risk of bias and extracted data. We rated the certainty of evidence with GRADE for the key outcomes of influenza, ILI, complications (hospitalisation, pneumonia), and adverse events. We have presented aggregate control group risks to illustrate the effect in absolute terms. We used them as the basis for calculating the number needed to vaccinate to prevent one case of each event for influenza and ILI outcomes.

MAIN RESULTS

We identified eight RCTs (over 5000 participants), of which four assessed harms. The studies were conducted in community and residential care settings in Europe and the USA between 1965 and 2000. Risk of bias reduced our certainty in the findings for influenza and ILI, but not for other outcomes.Older adults receiving the influenza vaccine may experience less influenza over a single season compared with placebo, from 6% to 2.4% (risk ratio (RR) 0.42, 95% confidence interval (CI) 0.27 to 0.66; low-certainty evidence). We rated the evidence as low certainty due to uncertainty over how influenza was diagnosed. Older adults probably experience less ILI compared with those who do not receive a vaccination over the course of a single influenza season (3.5% versus 6%; RR 0.59, 95% CI 0.47 to 0.73; moderate-certainty evidence). These results indicate that 30 people would need to be vaccinated to prevent one person experiencing influenza, and 42 would need to be vaccinated to prevent one person having an ILI.The study providing data for mortality and pneumonia was underpowered to detect differences in these outcomes. There were 3 deaths from 522 participants in the vaccination arm and 1 death from 177 participants in the placebo arm, providing very low-certainty evidence for the effect on mortality (RR 1.02, 95% CI 0.11 to 9.72). No cases of pneumonia occurred in one study that reported this outcome (very low-certainty evidence). No data on hospitalisations were reported. Confidence intervaIs around the effect of vaccines on fever and nausea were wide, and we do not have enough information about these harms in older people (fever: 1.6% with placebo compared with 2.5% after vaccination (RR 1.57, 0.92 to 2.71; moderate-certainty evidence)); nausea (2.4% with placebo compared with 4.2% after vaccination (RR 1.75, 95% CI 0.74 to 4.12; low-certainty evidence)).

AUTHORS' CONCLUSIONS

Older adults receiving the influenza vaccine may have a lower risk of influenza (from 6% to 2.4%), and probably have a lower risk of ILI compared with those who do not receive a vaccination over the course of a single influenza season (from 6% to 3.5%). We are uncertain how big a difference these vaccines will make across different seasons. Very few deaths occurred, and no data on hospitalisation were reported. No cases of pneumonia occurred in one study that reported this outcome. We do not have enough information to assess harms relating to fever and nausea in this population.The evidence for a lower risk of influenza and ILI with vaccination is limited by biases in the design or conduct of the studies. Lack of detail regarding the methods used to confirm the diagnosis of influenza limits the applicability of this result. The available evidence relating to complications is of poor quality, insufficient, or old and provides no clear guidance for public health regarding the safety, efficacy, or effectiveness of influenza vaccines for people aged 65 years or older. Society should invest in research on a new generation of influenza vaccines for the elderly.

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.

Epidemiological and economic impact of pandemic influenza in Chicago: Priorities for vaccine interventions

The study objective is to estimate the epidemiological and economic impact of vaccine interventions during influenza pandemics in Chicago, and assist in vaccine intervention priorities. Scenarios of delay in vaccine introduction with limited vaccine efficacy and limited supplies are not unlikely in future influenza pandemics, as in the 2009 H1N1 influenza pandemic. We simulated influenza pandemics in Chicago using agent-based transmission dynamic modeling. Population was distributed among high-risk and non-high risk among 0–19, 20–64 and 65+ years subpopulations. Different attack rate scenarios for catastrophic (30.15%), strong (21.96%), and moderate (11.73%) influenza pandemics were compared against vaccine intervention scenarios, at 40% coverage, 40% efficacy, and unit cost of $28.62. Sensitivity analysis for vaccine compliance, vaccine efficacy and vaccine start date was also conducted. Vaccine prioritization criteria include risk of death, total deaths, net benefits, and return on investment. The risk of death is the highest among the high-risk 65+ years subpopulation in the catastrophic influenza pandemic, and highest among the high-risk 0–19 years subpopulation in the strong and moderate influenza pandemics. The proportion of total deaths and net benefits are the highest among the high-risk 20–64 years subpopulation in the catastrophic, strong and moderate influenza pandemics. The return on investment is the highest in the high-risk 0–19 years subpopulation in the catastrophic, strong and moderate influenza pandemics. Based on risk of death and return on investment, high-risk groups of the three age group subpopulations can be prioritized for vaccination, and the vaccine interventions are cost saving for all age and risk groups. The attack rates among the children are higher than among the adults and seniors in the catastrophic, strong, and moderate influenza pandemic scenarios, due to their larger social contact network and homophilous interactions in school. Based on return on investment and higher attack rates among children, we recommend prioritizing children (0–19 years) and seniors (65+ years) after high-risk groups for influenza vaccination during times of limited vaccine supplies. Based on risk of death, we recommend prioritizing seniors (65+ years) after high-risk groups for influenza vaccination during times of limited vaccine supplies.

The study objective is to estimate the epidemiological and economic impact of vaccine interventions during an influenza pandemic in Chicago, to assist in vaccine intervention priorities. Population dynamics play an important role in influenza pandemic planning and response. To optimally allocate limited vaccine resources, it is important to inform decision makers and public health officials about both the direct benefit among vaccinated population and the indirect benefit among non-vaccinated population. This study adds to the evidence of prior studies by using a detailed agent-based model for estimating the direct and indirect benefits of epidemiological and economic impact of vaccine-based interventions. This study can be extended to analyze for a range of vaccine compliance and efficacy values at different attack rates of influenza pandemics in different rural and urban areas of the United States and at the country level, to infer objective prioritization criteria for influenza vaccine interventions among different risk and age groups.

Comparison of Side Effects of the 2015-2016 High-Dose, Inactivated, Trivalent Influenza Vaccine and Standard Dose, Inactivated, Trivalent Influenza Vaccine in Adults ≥65 Years

BACKGROUND

High-dose, inactivated, trivalent influenza vaccine (HD) is associated with higher rates of side effects than standard dose (SD) vaccine, which may represent a barrier to use.

METHODS

We surveyed subjects ≥65 years who received either HD or SD vaccine at the Minneapolis Veteran Affairs Health Care System clinics on October 27, 28, or 29, 2015. Research assistants conducted a 17-item telephone survey of influenza vaccine recipients to inquire about self-reported health and symptoms experienced the week after vaccination.

RESULTS

A total of 547 HD recipients and 541 SD recipients responded to the survey. The 2 groups were similar at baseline with respect to age, gender, and presence of high-risk medical conditions. At least ≥95% of individuals in both HD and SD groups reported that their overall health was the same or better than usual during the week after vaccination. Thirty-seven percent of HD recipients and 22% of SD recipients reported a local or systemic side effect (P < .001), most of which were mild to moderate. Only 7 of 547 (1.3%) HD recipients and 3 of 541 (0.6%) SD recipients reported a severe side effect (P = .34). There was no significant difference in healthcare visits between the groups.

CONCLUSIONS

Side effects were more common among subjects ≥65 years who received HD influenza vaccine compared with SD vaccine. These side effects were well tolerated and were not associated with impairment of general health status. These findings should reassure patients and their providers of the safety and tolerability of the HD influenza vaccine.

Prevention and Control of Seasonal Influenza with Vaccines

This report updates the 2015-16 recommendations of the Advisory Committee on Immunization Practices (ACIP) regarding the use of seasonal influenza vaccines (Grohskopf LA, Sokolow LZ, Olsen SJ, Bresee JS, Broder KR, Karron RA. Prevention and control of influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices, United States, 2015-16 influenza season. MMWR Morb Mortal Wkly Rep 2015;64:818-25). Routine annual influenza vaccination is recommended for all persons aged ≥6 months who do not have contraindications. For the 2016-17 influenza season, inactivated influenza vaccines (IIVs) will be available in both trivalent (IIV3) and quadrivalent (IIV4) formulations. Recombinant influenza vaccine (RIV) will be available in a trivalent formulation (RIV3). In light of concerns regarding low effectiveness against influenza A(H1N1)pdm09 in the United States during the 2013-14 and 2015-16 seasons, for the 2016-17 season, ACIP makes the interim recommendation that live attenuated influenza vaccine (LAIV4) should not be used. Vaccine virus strains included in the 2016-17 U.S. trivalent influenza vaccines will be an A/California/7/2009 (H1N1)-like virus, an A/Hong Kong/4801/2014 (H3N2)-like virus, and a B/Brisbane/60/2008-like virus (Victoria lineage). Quadrivalent vaccines will include an additional influenza B virus strain, a B/Phuket/3073/2013-like virus (Yamagata lineage).Recommendations for use of different vaccine types and specific populations are discussed. A licensed, age-appropriate vaccine should be used. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended product is otherwise appropriate. This information is intended for vaccination providers, immunization program personnel, and public health personnel. Information in this report reflects discussions during public meetings of ACIP held on October 21, 2015; February 24, 2016; and June 22, 2016. These recommendations apply to all licensed influenza vaccines used within Food and Drug Administration-licensed indications, including those licensed after the publication date of this report. Updates and other information are available at CDC's influenza website (http://www.cdc.gov/flu). Vaccination and health care providers should check CDC's influenza website periodically for additional information.

Overview of Infections in the Immunocompromised Host

Understanding the components of the immune system that contribute to host defense against infection is key to recognizing infections that are more likely to occur in an immunocompromised patient. In this review, we discuss the integrated system of physical barriers and of innate and adaptive immunity that contributes to host defense. Specific defects in the components of this system that predispose to particular infections are presented. This is followed by a review of primary immunodeficiency diseases and secondary immunodeficiencies, the latter of which develop because of a specific illness or condition or are treatment-related. The effects of treatment for neoplasia, autoimmune diseases, solid organ and stem cell transplants on host defenses are reviewed and associated with susceptibility to particular infections. In conclusion, an approach to laboratory screening for a suspected immunodeficiency is presented. Knowledge of which host defects predispose to specific infections allows clinicians to prevent, diagnose, and manage infections in their immunocompromised patients most effectively.

Association between monovalent influenza A (H1N1) pdm09 vaccine and pneumonia among the elderly in the 2009-2010 season in Japan: A case-control study

We investigated the association between monovalent influenza A (H1N1) pdm09 (H1N1pdm) vaccine and pneumonia in elderly people. Study design was a hospital-based, matched case-control study. Cases comprised patients ≥ 65 years old who had been newly diagnosed with pneumonia. For each case, 2 controls were defined as individuals with other diseases (not pneumonia) who were matched by sex, age, entry date, and the visited hospital. Study period was the interval from 1 September 2009 until 30 September 2010. Because a pandemic of influenza A (H1N1) occurred during study period, we analyzed selected subjects who had enrolled during the influenza A (H1N1) pandemic. We calculated the odds ratios (ORs) and 95% confidence intervals (CIs) for pneumonia in H1N1pdm-vaccinated subjects compared with unvaccinated subjects using a conditional logistic regression model to assess the association between H1N1pdm vaccine and pneumonia. The subjects during the period of the influenza A (H1N1) pandemic were 20 cases and 40 controls. Subjects who had received H1N1pdm vaccine showed a significantly decreased OR for pneumonia (OR = 0.10, 95% CI = 0.01-0.98) compared with unvaccinated subjects. In conclusion, H1N1pdm vaccination may have prevented pneumonia among the elderly during the 2009-2010 influenza A (H1N1) pandemic in Japan.

Economic Evaluation of Standing Order Programs for Pneumococcal Vaccination of Hospitalized Elderly Patients

Background.

Standing order programs (SOPs), which allow for vaccination without an individual physician order, are the most effective mechanism to achieve high vaccination rates. Among the suggested settings for the utilization of SOPs are hospital inpatient units, because they provide care for those most likely to benefit from vaccination. The cost-effectiveness of this approach for elderly hospitalized persons is unknown. The purpose of this study was to estimate the cost-effectiveness of SOPs for pneumococcal polysaccharide vaccine (PPV) vaccination for patients 65 years of age or older in 2 types of hospital.

Methods.

In 2004, a 1,094-bed tertiary care hospital implemented a pharmacy-based SOP for PPV, and a 225-bed community hospital implemented a nursing-based SOP for PPV. Newly admitted patients 65 years of age or older were screened for PPV eligibility and then offered PPV. Vaccination rates before and after initiation of SOPs in the United States, incidence rates of invasive pneumococcal disease in the United States, and US economic data were the bases of the cost-effectiveness analyses. One-way and multivariate sensitivity analyses were conducted.

Results.

PPV vaccination rates increased 30.5% in the tertiary care hospital and 15.3% in the community hospital. In the base-case cost-effectiveness analysis, using a societal perspective, we found that both pharmacy-based and nursing-based SOPs cost less than $10,000 per quality-adjusted life-year gained, with program costs (pharmacy-based SOPs cost $4.16 per patient screened, and nursing-based SOPs cost $4.60 per patient screened) and vaccine costs ($18.33 per dose) partially offset by potential savings from cases of invasive pneumococcal disease avoided ($12,436 per case). Sensitivity analyses showed SOPs for PPV vaccination to be cost-effective, compared with PPV vaccination without SOPs, unless the improvement in vaccination rate was less than 8%.

Conclusion.

SOPs do increase PPV vaccination rates in hospitalized elderly patients and are economically favorable, compared with PPV vaccination rates without SOPs.

A review of the indirect protection of younger children and the elderly through a mass influenza vaccination program in Japan

In the past, Japan's strategy for controlling influenza was to vaccinate schoolchildren based on the theory that this could reduce influenza epidemics in the community, and a special program to vaccinate schoolchildren against influenza was begun in 1962. However, the program was discontinued in 1994 because of lack of evidence that it had limited the spread of influenza in the community. In 2001, it was reported that a clear decrease in excess mortality had coincided with the timing of the schoolchild vaccination program. This decrease could have potentially occurred because elderly people were protected by herd immunity generated by the program. Moreover, the program protected the younger siblings of schoolchildren against influenza-associated encephalopathy. Finally, the program was effective in reducing the number of class cancellations and absenteeism from school. During the period when the program was in effect, Japanese schoolchildren served as a barrier against influenza in the community.

Cystine and theanine: amino acids as oral immunomodulative nutrients

The decreases in the glutathione (GSH) level in the mouse spleen and liver after immune stimulation are suppressed by the oral administration of cystine and theanine (CT). GSH is considered to be important for the control of immune responses. Antibody production in mice after infection is enhanced by the oral administration of CT. In humans, also, the oral administration of CT has been confirmed to enhance antibody production after vaccination against Flu and also reduce the incidence of cold. However, the GSH level is reduced by intense exercise and surgery. In clinical studies of body-builders and long-distance runners, the intake of CT suppressed excessive inflammatory reactions and a decline in immune functions after intense training. Surgery as well as intense exercise induces excessive inflammatory reactions. In mice, the preoperative administration of CT suppressed excessive inflammatory reactions associated with surgery and promoted the postoperative recovery. Moreover, in clinical studies of gastrectomized patients, CT intake suppressed excessive postoperative inflammatory reactions and induced early recovery. If infection is regarded as invasive stress, CT intake is considered to exhibit an immunomodulatory effect by suppressing the decrease in GSH due to invasive stress. The clarification of their detailed action mechanisms and their application as medical or function foods is anticipated.

Additive preventive effect of influenza and pneumococcal vaccines in the elderly: results of a large cohort study

Elderly people are at increased risk of influenza and pneumococcal diseases. Influenza increases clinical pneumococcal disease incidence. Pneumococcal vaccination could therefore be a supplement to influenza vaccination. This study evaluated all-cause mortality and antibiotic consumption according to elderly people's influenza and pneumococcal vaccination status. Its goal was to demonstrate that vaccination with both Influenza and pneumococcal vaccines decrease all-cause mortality and antibiotic consumption. From 2004-10-01 to 2004-12-31 (3 mo), elderly people (≥ 65 y) who lived in the Gard department (South of France) were offered both vaccinations. Among the 68,897 subjects followed-up one year after this vaccination campaign, 21,303 (30.9%) were vaccinated with both vaccines, 18,651 (27.1%) with influenza vaccine alone, 3,769 (5.5%) with pneumococcal vaccine alone; 25,174 (36.5%) subjects were unvaccinated. Mortality rate (per 1,000 inhabitants-year) adjusted on gender, age and prior underlying chronic disease was 17.9 (95% CI: 16.3-19.6), 20.8 (19.0-22.8), 22.5 (19.0-26.6) and 24.7 (22.7-26.8), respectively. It was 42.1 (38.8-45.8) in elderly people with underlying chronic disease who received both vaccines vs. 58.1 (53.7-62.9) in unvaccinated elderly people. The decrease in mortality rate was 27.0% (20.0-34.0) in subjects who received both vaccines and 16.0% (6.0-24.0) in those who received influenza vaccine. No significant reduction in mortality rate was seen with the pneumococcal vaccine alone. Influenza and/or pneumococcal vaccinations did not decrease antibiotic consumption that drastically increases during the winter period. An additive effect was observed in the prevention of all-cause mortality with influenza and pneumococcal vaccines given together in elderly people, including in those with underlying chronic disease.

Influenza vaccines in low and middle income countries: a systematic review of economic evaluations

OBJECTIVES

Economic evaluations on influenza vaccination from low resource settings are scarce and have not been evaluated using a systematic approach. Our objective was to conduct a systematic review on the value for money of influenza vaccination in low- and middle-income countries.

METHODS

PubMed and EMBASE were searched for economic evaluations published in any language between 1960 and 2011. Main outcome measures were costs per influenza outcome averted, costs per quality-adjusted life years gained or disability-adjusted life years averted, costs per benefit in monetary units or cost-benefit ratios.

RESULTS

Nine economic evaluations on seasonal influenza vaccine met the inclusion criteria. These were model- or randomized-controlled-trial (RCT)-based economic evaluations from middle-income countries. Influenza vaccination provided value for money for elderly, infants, adults and children with high-risk conditions. Vaccination was cost-effective and cost-saving for chronic obstructive pulmonary disease patients and in elderly above 65 y from model-based evaluations, but conclusions from RCTs on elderly varied.

CONCLUSION

Economic evaluations from middle income regions differed in population studied, outcomes and definitions used. Most findings are in line with evidence from high-income countries highlighting that influenza vaccine is likely to provide value for money. However, serious methodological limitations do not allow drawing conclusions on cost-effectiveness of influenza vaccination in middle income countries. Evidence on cost-effectiveness from low-income countries is lacking altogether, and more information is needed from full economic evaluations that are conducted in a standardized manner.

Voluntary reporting of health care personnel seasonal influenza vaccination rates and the impact of universal policies in Illinois hospitals

OBJECTIVE

In 2009, voluntary public reporting of hospital health care personnel (HCP) vaccination rates began in Illinois. We describe our experience over 3 influenza seasons and examine the impact universal policies have had on performance.

METHODS

A secure website was used to report monthly HCP vaccination rates by each participating hospital. Overall and individual hospital performance was publicly reported each month.

RESULTS

In the first two seasons, there were 11 hospitals reporting with an average end of season rate of 76% (2009-2010) and 81% (2010-2011). In the 2011-2012 season, there were 22 hospitals reporting, 9 of which had a new universal policy for HCP influenza vaccination. The average 2011-2012 end of season rate was 72% for hospitals with a voluntary program and 95% for hospitals with a universal policy. HCP were also vaccinated earlier in the influenza season when a universal policy was in place, providing greater benefit over time.

CONCLUSION

Public reporting of HCP influenza vaccination rates may contribute to implementation of universal employee vaccination policies. Hospitals with universal policies have higher vaccination rates than those with voluntary vaccination programs.

Targeting the skin for microneedle delivery of influenza vaccine

Influenza infection represents a major socioeconomic burden worldwide. Skin represents a new target that has gained much attention in recent years for delivery of influenza vaccine as an alternative to the conventional intramuscular route of immunization. In this review we describe different microneedle vaccination approaches used in vivo, including metal and dissolving microneedle patches that have demonstrated promising results. Additionally we analyze the immunological basis for microneedle skin immunization and targeting of the skin's dense population of antigen presenting cells, their role, characterization, and function. Additionally we analyze the importance of inflammatory signaling in the skin after microneedle delivery.

Effectiveness of adjuvanted seasonal influenza vaccines (Inflexal V ® and Fluad ® ) in preventing hospitalization for influenza and pneumonia in the elderly: a matched case-control study

Annual vaccination is the main mean of preventing influenza in the elderly. In order to evaluate the effectiveness of the adjuvanted seasonal influenza vaccines available in Italy in preventing hospitalization for influenza and pneumonia, a matched case-control study was performed in elderly subjects during the 2010–2011 season in Genoa (Italy). Cases and controls were matched in a 1:1 ratio according to gender, age, socio-economic status and type of influenza vaccine. Vaccine effectiveness was calculated as IVE = [(1-OR)x100] and crude odds ratios were estimated through conditional logistic regression models. Adjusted odds ratios were estimated through multivariable logistic models.

In the study area, influenza activity was moderate in the 2010–2011 season, with optimal matching between circulating viruses and vaccine strains. We recruited 187 case-control pairs; 46.5% of cases and 79.1% of controls had been vaccinated. The adjuvanted influenza vaccines (Fluad^® considered together with Inflexal V^®) were associated with a significant reduction in the risk of hospitalization, their effectiveness being 94.8% (CI 77.1–98.8). Adjusted vaccine effectiveness was 95.2% (CI 62.8–99.4) and 87.8 (CI 0.0–98.9) for Inflexal V^® and Fluad^®, respectively. Both adjuvanted vaccines proved effective, although the results displayed statistical significance only for Inflexal V^® (p = 0.004), while for Fluad^® statistical significance was not reached (p = 0.09). Our study is the first to provide information on the effectiveness of Inflexal V^® in terms of reducing hospitalizations for influenza or pneumonia in the elderly, and demonstrates that this vaccine yields a high degree of protection and that its use would generate considerable saving for the National Health Service.

Reduced incidence of pneumonia in influenza-vaccinated solid organ transplant recipients with influenza disease

Clin Microbiol Infect

Abstract

Whether influenza vaccination influences the severity of illness in cases of clinical failure in solid organ transplant (SOT) recipients receiving influenza vaccine has not been extensively studied. Our goal was to evaluate the frequency of influenza vaccination among SOT recipients with influenza disease and its impact on the illness severity during the 2010–2011 season. Adult SOT recipients with confirmed influenza infection were included from December 2010 to April 2011. Follow‐up data were recorded and antibody titres were determined using a microneutralization assay. Sixty‐four SOT recipients were included in the study, ten (15.6%) with severe disease, requiring admission to intensive care units, of whom four (6.3%) died. In all, 34 (53.1%) received the 2010–2011 seasonal influenza vaccine and 32 (50.0%) received the 2009‐H1N1 pandemic vaccine, and none had detectable antibodies against influenza at the time of diagnosis of influenza infection. Twenty‐three (67.6%) of the patients that received the vaccine required hospital admission and presented less dyspnoea (10, 29.4% versus 14 (50.0%), p 0.09) and pneumonia (8, 23.8% versus 15, 50.0%, p 0.03, relative risk 0.3, 95% CI 0.1–0.9) than unvaccinated patients, with relative risk reductions of 60% and 70%, respectively. Although influenza vaccination confers protection on SOT recipients against developing influenza pneumonia, the rate of clinical failure is still high. New strategies to improve influenza immunization are needed for this group of patients.

Further evidence for favorable cost-effectiveness of elderly influenza vaccination

Vaccination represents the single most cost-effective strategy to avert influenza-related morbidity, mortality and economic consequences. This review presents an analysis of the pharmacoeconomic aspects of influenza vaccination of the elderly. The methodology of the analysis focuses on the main drivers of the pharmacoeconomic profile of elderly influenza vaccination, in particular the vaccine effectiveness in terms of prevention of hospitalization and mortality, the background incidence of hospitalization and death in unvaccinated individuals and the relative costing of the vaccine compared with the costs of a hospital in-patient day. The variation in outcomes between different studies could partly be explained by differences in the main drivers defined above. This review demonstrates that the pharmacoeconomic profile of elderly influenza vaccination is highly favorable. From the vast majority of studies it appears that financial benefits of elderly influenza vaccination surpass the costs and that, when this is not the case, cost-effectiveness in terms of net costs per life-year gained is acceptable.

Cost-effectiveness of polysaccharide pneumococcal vaccination in people aged 65 and above in Poland

INTRODUCTION

Invasive pneumococcal disease is associated with substantial morbidity, mortality and cost implications, which could be reduced by vaccination.

AIM

To assess the cost-effectiveness of a 23-valent pneumococcal vaccine in the elderly (65 and older) in Poland.

METHODS

A Markov model with a 1-year cycle length was developed, allowing up to 10 cohorts to enter the model over the lifetime horizon (35 years). In the base case, costs and benefits were assessed using the public health care payer (NFZ) perspective. The analysis included routine vaccination of all elderly and high-risk (HR) elderly versus no vaccination. The analysis assumed that the government would reimburse 50% of the vaccine price. Costs and benefits were discounted 5%, with costs expressed in 2009 Polish Zloty (PLN). Extensive sensitivity analyses were carried out.

RESULTS

PPV23 vaccination targeting all elderly and HR elderly in Poland would avoid 8,935 pneumococcal infections, 2,542 hospitalisations, 671 deaths and 5,886 infections, 1,673 hospitalisations and 441 deaths respectively. The incremental cost per QALY gained would be PLN 3,382 in all elderly and PLN2,148 in HR elderly.

CONCLUSION

Vaccinating adults 65 and older regardless of risk status with a 23-valent pneumococcal vaccine, is cost-effective, resulting in clinical and economic benefits including a non-negligible reduction of ambulatory doctor visits, hospitalizations and, deaths in Poland.

A surveillance system to reduce transmission of pandemic H1N1 (2009) influenza in a 2600-bed medical center

Background

Concerns have been raised about how the transmission of emerging infectious diseases from patients to healthcare workers (HCWs) and vice versa could be recognized and prevented in a timely manner. An effective strategy to block transmission of pandemic H1N1 (2009) influenza in HCWs is important.

Methodology/Principal Findings

An infection control program was implemented to survey and prevent nosocomial outbreaks of H1N1 (2009) influenza at a 2,600-bed, tertiary-care academic hospital. In total, 4,963 employees at Kaohsiung Chang Gung Memorial Hospital recorded their temperature and received online education on control practices for influenza infections. Administration records provided vaccination records and occupational characteristics of all HCWs. Early recognition of a pandemic H1N1 (2009) influenza case was followed by a semi-structured questionnaire to analyze possible routes of patient contact, household contact, or unspecified contact. Surveillance spanned August 1, 2009 to January 31, 2010; 51 HCWs were confirmed to have novel H1N1 (2009) influenza by quantitative real-time reverse transcription polymerase chain reaction. Prevalence of patient contact, household contact, or unspecified contact infection was 13.7% (7/51), 13.7% (7/51), and 72.5% (37/51), respectively. The prevalence of the novel H1N1 infection was significantly lower among vaccinated HCWs than among unvaccinated HCWs (p<0.001). Higher viral loads in throat swabs were found in HCWs with patient and household contact infection than in those with unspecified contact infection (4.15 vs. 3.53 copies/mL, log₁₀, p = 0.035).

Conclusion

A surveillance system with daily temperature recordings and online education for HCWs is important for a low attack rate of H1N1 (2009) influenza transmission before H1N1 (2009) influenza vaccination is available, and the attack rate is further decreased after mass vaccination. Unspecified contact infection rates were significantly higher than that of patient contact and household contact infection, highlighting the need for public education of influenza transmission in addition to hospital infection control.

Effectiveness of influenza vaccine in aging and older adults: comprehensive analysis of the evidence

Foremost amongst the diseases preventable by vaccination is influenza. Worldwide, influenza virus infection is associated with serious adverse events leading to hospitalization, debilitating complications, and death in elderly individuals. Immunization is considered to be the cornerstone for preventing these adverse health outcomes, and vaccination programs are timed to optimize protection during the annual influenza season. Trivalent inactivated influenza virus vaccines are believed to be both effective and cost-saving; however, in spite of widespread influenza vaccination programs, rates of hospitalization for acute respiratory illness and cardiovascular diseases have been increasing in this population during recent annual influenza seasons. From meta-analyses summarizing estimates of influenza vaccine effectiveness from available observational clinical studies, this review aims to examine how effective current influenza vaccine strategies are in the aging and older adult population and to analyze which are the most important biases that interfere with measurements of influenza vaccine effectiveness. Furthermore, consideration is given to strategies that should be adopted in order to optimize influenza vaccine effectiveness in the face of immune exhaustion.

Economic value of influenza vaccination

Influenza epidemics are responsible for high mortality and morbidity rates in particular among elderly and high risk groups. This review is aimed at assessing the economic value of vaccination in these groups. A search of full economic evaluations of influenza vaccination in comparison with no interventions was performed on PubMed from January 1990 to May 2011. Only economic evaluations dealing with elderly and high risk groups were considered. The quality of selected articles was assessed through Drummond's checklist. Sixteen cost-effectiveness analyses and four cost-benefit analyses were included: overall, the quality of studies was fairly good. The vaccination was demonstrated to be cost-effective or cost-saving in almost all studies, independently by the perspective and the type of analysis. Influenza vaccination is a worthwhile intervention from the pharmacoeconomic view-point, anyway a standardization of methods should be desirable in order to guarantee the comparability and transferability of results.

Family physicians beliefs and attitudes regarding adult pneumococcal and influenza immunization in Lebanon

BACKGROUND

Influenza and pneumococcal diseases are responsible for more deaths than all other vaccine-preventable diseases combined. Despite all efforts, the vaccination rate is below target.

OBJECTIVES

To assess knowledge and beliefs of family physicians in Lebanon regarding influenza and pneumococcal vaccines, to identify adult immunization barriers, to assess physicians' use of evidence-based strategies to improve adult immunization and identify barriers to implementation of such strategies.

METHODS

All 52 Lebanese family physicians attending the annual family medicine conference in Beirut in November 2009 were asked to fill a self-administered questionnaire that included items inquiring about knowledge, beliefs, attitudes, barriers to these vaccines and their opinions regarding strategies to improve immunization rate.

RESULTS

Response rate was 82.7%. Accurate knowledge of influenza and pneumococcal vaccination guidelines was 58.1% and 53.5%, respectively. Thirty-eight physicians (88.4%) believe that influenza and pneumococcal vaccines are important, while 36 (83.7%) recommend influenza vaccine and 33 (76.7%) pneumococcal vaccine. Barriers for recommending vaccines were reported by 14 participants (32.5%). Concerning the influenza vaccine, the most commonly reported barriers were patient's refusal and non-availability of the vaccine, followed by physicians' concerns about efficacy and safety. As for the pneumococcal vaccine, the most frequently reported barriers were patient's refusal, cost and physicians concerns about efficacy. Insufficient time and unknown immunization status were reported to be barriers of lesser importance. Twenty-six physicians (61%) reported physicians' reminders as the most important intervention to promote adult immunization, followed by patient education (48%). Lack of time and availability of electronic medical record were cited as important strategies to increase adult immunization rate.

CONCLUSIONS

Education and intervention efforts are needed to overcome barriers faced by practitioners and to define the most effective strategies to overcoming these barriers.

What determines influenza vaccination take-up of elderly Europeans?

We analyse the determinants of influenza vaccination take-up of Europeans above the age of 50 years using the first two waves of the Survey of Health, Ageing, and Retirement (SHARE). Using quality-of-care indicators, special emphasis is put on the measurement and the impact of physician quality. We find that age, health status, lifestyle, labour-force status, and the family structure are important determinants of the decision to get a flu shot. Physician quality, as measured by four indicators, also positively affects the probability of getting a flu shot.

Efficacy of a vaccine that links viral epitopes to flagellin in protecting aged mice from influenza viral infection

Influenza vaccines are less effective in older people than younger people. This impaired ability to protect older people from influenza viral lung infection has important implications as older people suffer a higher morbidity and mortality from influenza viral lung infection than younger people. Therefore, the development of novel effective vaccines that induce protection from influenza viral infections in older people are urgently needed. We had previously shown that direct linking the TLR5 activator, flagellin, to viral peptides induces effective immunity to viral antigens in young mice and people, respectively. In this study, we tested the efficacy of this vaccine platform with the hemagglutinin peptide of the influenza A strain virus (vaccine denoted as STF2.HA1-2) in protecting aged mice from subsequent influenza viral lung infection. We found that a 3.0 μg dose of the vaccine was effective in reducing mortality and increasing clinical well-being during influenza viral lung infection in aged mice. However, this effect was inferior to the response induced in young mice. Defects in the adaptive immune system but not the innate immune system were associated with this reduced effectiveness of the vaccine with aging. Our results indicate that the STF2.HA1-2 vaccine is effective in protecting aged hosts from influenza lung infection, although defects in the adaptive immune system with aging may limit the effectiveness of this vaccine in older people.

Influenza vaccine effectiveness in the elderly based on administrative databases: change in immunization habit as a marker for bias

BACKGROUND

Administrative databases provide efficient methods to estimate influenza vaccine effectiveness (IVE) against severe outcomes in the elderly but are prone to intractable bias. This study returns to one of the linked population databases by which IVE against hospitalization and death in the elderly was first assessed. We explore IVE across six more recent influenza seasons, including periods before, during, and after peak activity to identify potential markers for bias.

METHODS AND FINDINGS

Acute respiratory hospitalization and all-cause mortality were compared between immunized/non-immunized community-dwelling seniors ≥65 years through administrative databases in Manitoba, Canada between 2000-01 and 2005-06. IVE was compared during pre-season/influenza/post-season periods through logistic regression with multivariable adjustment (age/sex/income/residence/prior influenza or pneumococcal immunization/medical visits/comorbidity), stratification based on prior influenza immunization history, and propensity scores. Analysis during pre-season periods assessed baseline differences between immunized and unimmunized groups. The study population included ∼140,000 seniors, of whom 50-60% were immunized annually. Adjustment for key covariates and use of propensity scores consistently increased IVE. Estimates were paradoxically higher pre-season and for all-cause mortality vs. acute respiratory hospitalization. Stratified analysis showed that those twice consecutively and currently immunized were always at significantly lower hospitalization/mortality risk with odds ratios (OR) of 0.60 [95%CI0.48-0.75] and 0.58 [0.53-0.64] pre-season and 0.77 [0.69-0.86] and 0.71 [0.66-0.77] during influenza circulation, relative to the consistently unimmunized. Conversely, those forgoing immunization when twice previously immunized were always at significantly higher hospitalization/mortality risk with OR of 1.41 [1.14-1.73] and 2.45 [2.21-2.72] pre-season and 1.21 [1.03-1.43] and 1.78 [1.61-1.96] during influenza circulation.

CONCLUSIONS

The most pronounced IVE estimates were paradoxically observed pre-season, indicating bias tending to over-estimate vaccine protection. Change in immunization habit from that of the prior two years may be a marker for this bias in administrative data sets; however, no analytic technique explored could adjust for its influence. Improved methods to achieve valid interpretation of protection in the elderly are needed.

Vaccine effectiveness in older individuals: what has been learned from the influenza-vaccine experience

Vaccination policies in most high-income countries attempt to reduce the adverse impact of influenza targeting people aged at least 60 years. However, while it is widely believed that the current immunization strategy saves many lives, influenza infection still remains a severe burden in aged individuals leading to a wide debate on the exact magnitude of the benefit of vaccination in this population. The first aim of the present review is to examine how effective current influenza-vaccine strategies are in aged adults, by analysing which are the most important factors modulating the interpretation of study results in this population. Furthermore, consideration will be given to how immune factors influence the measurement of vaccine efficacy/effectiveness, where advancing age leads to deleterious changes in the adaptive immune system, resulting in less than optimal responses to infectious agents and vaccination. Finally this review concludes with possible strategies to improve the ability of the senescent immune system to respond to vaccination.

[Flu vaccination in the elderly]

Seasonal flu is a very serious public health problem in the elderly due to its morbidity and mortality and financial and social costs arising from this. The aim of this review is to describe the magnitude and importance of seasonal flu in this population group, and its prevention by means of vaccination. For this reason, an updated account of the composition of the vaccine, its dosage and administration route, vaccine safety and the evaluation of the immunogenicity and effectiveness of vaccination. There is variation between different countries and official organisations on the age at which flu vaccination must be established in the elderly. New flu vaccination strategies need to be introduced, to further improve flu vaccination cover in Spain.

Workplace efforts to promote influenza vaccination among healthcare personnel and their association with uptake during the 2009 pandemic influenza A (H1N1)

BACKGROUND

Survey data suggest that, in a typical year, less than half U.S. healthcare personnel (HCP) are vaccinated for influenza. We measured workplace efforts to promote influenza vaccination among HCP in the U.S. and their association with seasonal and pandemic vaccination during the 2009-10 influenza season.

METHODS

Self-reported survey data collected in June 2010 from eligible HCP (n=1714) participating in a nationally representative, online research panel. HCP eligible for participation in the survey were those reporting as patient care providers and/or working in a healthcare setting. The survey measured workplace exposure to vaccination recommendations, vaccination requirements, on-site vaccination, reminders, and/or rewards, and being vaccinated for seasonal or H1N1 influenza.

RESULTS

At least two-thirds of HCP were offered worksite influenza vaccination; about one half received reminders; and 10% were required to be vaccinated. Compared to HCP in other work settings, hospital employees were most (p<0.001) likely to be the subject to efforts to promote vaccination. Vaccination requirements were associated with increases in seasonal and pandemic vaccination rates of between 31 and 49% points (p<0.005). On-site vaccination was associated with increases in seasonal and pandemic vaccination of between 13 and 29% points (p<0.05). Reminders and incentives were not associated with vaccination.

CONCLUSIONS

Our findings provide empirical support for vaccination requirements as a strategy for increasing influenza vaccination among HCP. Our findings also suggest that making influenza vaccination available to HCP at work could increase uptake and highlight the need to reach beyond hospitals in promoting vaccination among HCP.

Does influenza vaccination of older adult Medicare beneficiaries lower treatment costs for acute and chronic respiratory disease?

BACKGROUND

Influenza accounts for a large proportion of hospitalizations and deaths among older adults, resulting in substantial health care expenses. Influenza vaccinations are effective in reducing respiratory infections in younger populations, but it is less certain whether they reduce costs associated with respiratory infections among older adults.

OBJECTIVE

The purpose of this study was to determine whether influenza vaccination of older adult Medicare beneficiaries reduced costs associated with acute and chronic respiratory conditions during 3 recent influenza seasons.

METHODS

This study analyzed the relationship between influenza vaccination and costs for respiratory conditions among Medicare beneficiaries >or=55 years of age in influenza seasons (October-May) between 2002 and 2005 using data from the Medicare Current Beneficiary Survey. Two-part multiple regressions of vaccination status were estimated on the probability and cost of treating respiratory conditions in each influenza season controlling for influenza risk factors and other covariates. Various sensitivity tests were conducted by type of service, subgroup analysis for specific population risk segments, propensity score-matched comparisons, and difference equations.

RESULTS

The study sample included 13,402 Medicare beneficiaries for the 3 influenza seasons examined. Vaccination rates varied between 67.3% and 74.9% over the 3 influenza seasons. In unadjusted comparisons, no significant difference in the cost of treating respiratory conditions was found between vaccinated and unvaccinated beneficiaries in 2002/2003 (-$104), but vaccinated beneficiaries had significantly higher mean cost differentials in the more recent influenza seasons ($258 in 2003/2004, P = 0.012; $254 in 2004/2005, P = 0.003). Based on 2-part multiple regressions of vaccine status over the 3 seasons combined, costs of respiratory conditions were $142 dollars higher on average for vaccinated beneficiaries (P = 0.014). The base regression models showed no significant cost savings from vaccination in any year. Results of 2 of the 54 sensitivity tests that were conducted indicated significant savings from vaccination (inpatient costs for 2002/2003 and difference in total costs for persons unvaccinated in 2002/2003 but vaccinated in 2003/2004).

CONCLUSION

In this study of older adults, no significant cost savings were found with influenza vaccines in the 3 influenza seasons examined (2002-2005) when the outcome was measured in terms of differential spending for acute and chronic respiratory conditions.

Vaccines for preventing influenza in the elderly

BACKGROUND

Vaccines have been the main global weapon to minimise the impact of influenza in the elderly for the last four decades and are recommended worldwide for individuals aged 65 years or older. The primary goal of influenza vaccination in the elderly is to reduce the risk of complications among persons who are most vulnerable.

OBJECTIVES

To assess the effectiveness of vaccines in preventing influenza, influenza-like illness (ILI), hospital admissions, complications and mortality in the elderly. To identify and appraise comparative studies evaluating the effects of influenza vaccines in the elderly. To document types and frequency of adverse effects associated with influenza vaccines in the elderly.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Acute Respiratory Infections (ARI) Group's Specialised Register (The Cochrane Library 2009, issue 4); MEDLINE (January 1966 to October Week 1 2009); EMBASE (1974 to October 2009) and Web of Science (1974 to October 2009).

SELECTION CRITERIA

Randomised controlled trials (RCTs), quasi-RCTs, cohort and case-control studies assessing efficacy against influenza (laboratory-confirmed cases) or effectiveness against influenza-like illness (ILI) or safety. Any influenza vaccine given independently, in any dose, preparation or time schedule, compared with placebo or with no intervention was considered.

DATA COLLECTION AND ANALYSIS

We grouped reports first according to the setting of the study (community or long-term care facilities) and then by level of viral circulation and vaccine matching. We further stratified by co-administration of pneumococcal polysaccharide vaccine (PPV) and by different types of influenza vaccines. We analysed the following outcomes: influenza, influenza-like illness, hospital admissions, complications and deaths.

MAIN RESULTS

We included 75 studies. Overall we identified 100 data sets. We identified one RCT assessing efficacy and effectiveness. Although this seemed to show an effect against influenza symptoms it was underpowered to detect any effect on complications (1348 participants). The remainder of our evidence base included non-RCTs. Due to the general low quality of non-RCTs and the likely presence of biases, which make interpretation of these data difficult and any firm conclusions potentially misleading, we were unable to reach clear conclusions about the effects of the vaccines in the elderly.

AUTHORS' CONCLUSIONS

The available evidence is of poor quality and provides no guidance regarding the safety, efficacy or effectiveness of influenza vaccines for people aged 65 years or older. To resolve the uncertainty, an adequately powered publicly-funded randomised, placebo-controlled trial run over several seasons should be undertaken.

Influenza vaccines provide diminished protection but are cost-saving in older adults

Influenza is associated with substantial morbidity and mortality in adults aged over 65 years. Although vaccination remains the most effective method of preventing influenza and its sequellae, current vaccination strategies provide less protection to older adults than to younger persons. Influenza vaccination in community-dwelling older adults is cost-effective, though there is room for improvement. Newer vaccine strategies considered for use in older adults include alternate routes of administration (intradermal or intranasal), addition of adjuvant, and novel methods of antigen presentation. Measuring cell-mediated immune response to new vaccines in addition to antibody response may correlate better with vaccine efficacy in this population. Whilst pandemic influenza A/H1N1 2009 (pH1N1) has largely spared older adults, the impact of pH1N1 vaccination has yet to be determined.