Influenza vaccination reduces hospitalization for acute coronary syndrome in elderly patients with chronic obstructive pulmonary disease: a population-based cohort study

Infectious diseases, cardio-cerebrovascular health and vaccines: pathways to prevention

Cardiovascular and infectious diseases both feature among the leading causes of death among men and women in the world. The pathophysiological pathways of infection and cardiovascular disease intersect, and there is a bidirectional relationship between the two. Vaccines are available for the most common infectious diseases affecting older adults, such as influenza, pertussis, pneumococcal disease, herpes zoster, COVID and respiratory syncytial virus (RSV). In many countries, these vaccines are recommended systematically for older adults and any adults with comorbidities, who are also those most likely to suffer from cardiovascular disease. There is a large body of evidence attesting to the benefits of vaccination on cardio- and cerebrovascular health. The European Interdisciplinary Council for Aging (EICA) and the Italian Society for Cardiovascular Prevention (Società Italiana per la Prevenzione Cardiovascolare, SIPREC) convened a 2-day meeting in June 2024 to review the state of the evidence on the relationship between cardio- and cerebrovascular health and the most common infectious diseases, and the role of vaccines in preventing both infection and its adverse consequences in terms of cardiovascular and cerebrovascular outcomes. We present here the Executive Summary of the proceedings of this meeting.

Association of respiratory infections and the impact of vaccinations on cardiovascular diseases

Influenza, pneumococcal, severe acute respiratory syndrome coronavirus 2, and respiratory syncytial virus infections are important causes of high morbidity and mortality in the elderly. Beyond the burden of infectious diseases, they are also associated with several non-infectious complications like cardiovascular events. A growing body of evidence in prospective studies and meta-analyses has shown the impact of influenza and pneumococcal vaccines on types of cardiovascular outcomes in the general population. Influenza vaccination showed a potential benefit for primary and secondary prevention of cardiovascular diseases across all ages. A reduced risk of cardiovascular events for individuals aged 65 years and older was associated with pneumococcal vaccination. Despite scientific evidence on the effectiveness, safety, and benefits of the vaccines and recommendations to vaccinate elderly patients and those with risk factors, vaccination rates remain sub-optimal in this population. Doubts about vaccine necessity or efficacy and concerns about possible adverse events in patients and physicians refer to delayed acceptance. Vaccination campaigns targeting increasing professional recommendations and public perceptions should be implemented in the coming years. The aim of this review paper is to summarize the effect of vaccination in the field of cardiovascular disease to achieve a higher vaccination rate in this patient population.

Influenza vaccination for elderly, vulnerable and high-risk subjects: a narrative review and expert opinion

Influenza is associated with a substantial health burden, especially in high-risk subjects such as older adults, frail individuals and those with underlying chronic diseases. In this review, we summarized clinical findings regarding the impact of influenza in vulnerable populations, highlighted the benefits of influenza vaccination in preventing severe illness and complications and reviewed the main evidence on the efficacy, effectiveness and safety of the vaccines that are best suited to older adults among those available in Italy. The adverse outcomes associated with influenza infection in elderly and frail subjects and those with underlying chronic diseases are well documented in the literature, as are the benefits of vaccination (mostly in older adults and in patients with cardiovascular diseases, diabetes and chronic lung disease). High-dose and adjuvanted inactivated influenza vaccines were specifically developed to provide enhanced immune responses in older adults, who generally have low responses mainly due to immunosenescence, comorbidities and frailty. These vaccines have been evaluated in clinical studies and systematic reviews by international immunization advisory boards, including the European Centre for Disease Prevention and Control. The high-dose vaccine is the only licensed influenza vaccine to have demonstrated greater efficacy versus a standard-dose vaccine in preventing laboratory-confirmed influenza in a randomized controlled trial. Despite global recommendations, the vaccination coverage in high-risk populations is still suboptimal. All healthcare professionals (including specialists) have an important role in increasing vaccination rates.

Impact of influenza, herpes zoster, and pneumococcal vaccinations on the incidence of cardiovascular events in subjects aged over 65 years: a systematic review

This systematic review aims to summarize the impact of vaccination against influenza, shingles, and pneumococcus on the incidence on the risk of cardiovascular events in the elderly. This protocol was developed in accordance with PRISMA guidelines. We conducted a literature search and identified all relevant articles published regarding the matter up to September 2022. We retrieved 38 studies (influenza vaccine = 33, pneumococcal vaccine = 5, and zoster vaccine = 2). A total of 28 and 2 studies have shown that influenza and pneumococcal vaccines significantly lower the risk of cardiovascular disease in the elderly. Also, repeated influenza vaccination shows a consistent and dose-dependent protective effect against acute coronary syndromes and stroke. Moreover, dual influenza and pneumococcal vaccination was associated with lower risks of some cardiovascular events (stroke, congestive heart failure, ischemic heart disease, and myocardial infarction). However, the impact of PCV13 on cardiovascular events has not been studied, nor has the currently recommended vaccination schedule (PCV13 + PPV23). As for herpes zoster vaccination, only the protective effect against stroke has been studied with the live attenuated herpes zoster vaccine, but no studies have been conducted with the recombinant subunit herpes zoster vaccine. This review outlines the benefits of the vaccines mentioned above beyond their preventive action on infectious diseases. It is intended for health professionals who wish to inform and advise their elderly patients.

The need for vaccination in adults with chronic (noncommunicable) diseases in India - lessons from around the world

Worldwide, chronic diseases (noncommunicable diseases [NCDs]) cause 41 million (71%) deaths annually. They are the leading cause of mortality in India, contributing to 60% of total deaths each year. Individuals with these diseases are more susceptible to vaccine-preventable diseases (VPDs) and have an increased risk of associated disease severity and complications. This poses a substantial burden on healthcare systems and economies, exemplified by the COVID-19 pandemic. Vaccines are an effective strategy to combat these challenges; however, utilization rates are inadequate. With India running one of the world’s largest COVID-19 vaccination programs, this presents an opportunity to improve vaccination coverage for all VPDs. Here we discuss the burden of VPDs in those with NCDs, the benefit of vaccinations, current challenges and possible strategies that may facilitate implementation and accessibility of vaccination programs. Effective vaccination will have a significant impact on the disease burden of both VPDs and NCDs and beyond.

What is already known on this topic?

Annually, chronic or noncommunicable diseases (NCDs) cause >40 million deaths worldwide and 60% of all deaths in India

Adults with these diseases are more susceptible to vaccine-preventable diseases (VPDs); however, vaccine utilization is inadequate in this population

What is added by this report?

We highlight the benefits of vaccination in adults with NCDs that extend beyond disease prevention

We discuss key challenges in implementing adult vaccination programs and provide practical solutions

What are the implications for public health practice?

Raising awareness about the benefits of vaccinations, particularly for those with NCDs, and providing national guidelines with recommendations from medical societies, will increase vaccine acceptance

Adequate vaccine acceptance will reduce the VPD burden in this vulnerable population

Effect of Influenza Vaccination on the Reduction of the Incidence of Chronic Kidney Disease and Dialysis in Patients with Type 2 Diabetes Mellitus

Patients with type 2 diabetes mellitus (T2DM) have a higher risk of chronic kidney disease (CKD) due to vascular complications and chronic inflammation. T2DM contributes to a higher risk of mortality and morbidity related to influenza. In Taiwan, influenza vaccination is recommended for patients with T2DM. A previous meta-analysis reported the efficacy of influenza vaccination in reducing hospitalization and mortality in patients with diabetes; however, the renal protective effect of the vaccine remains unclear. This study evaluated whether influenza vaccination could reduce the incidence of CKD and dialysis in patients with T2DM. The study cohort included all patients aged ≥55 years who were diagnosed as having T2DM between 1 January 2000 and 31 December 2012, by using data from Taiwan’s National Health Insurance Research Database. Each patient was followed up with to assess factors associated with CKD. A time-dependent Cox proportional hazard regression model after adjustment for potential confounders was used to calculate the hazard ratio (HR) of CKD in the vaccinated and unvaccinated patients. The study population comprised 48,017 eligible patients with DM; 23,839 (49.7%) received influenza vaccination and the remaining 24,178 (50.3%) did not. The adjusted HRs (aHRs) for CKD/dialysis decreased in the vaccinated patients compared with the unvaccinated patients (influenza season, noninfluenza season, and all seasons: aHRs: 0.47/0.47, 0.48/0.49, and 0.48/0.48, respectively, all p < 0.0001). We observed similar protective effects against CKD during the influenza and noninfluenza seasons. Regardless of comorbidities or drug use, influenza vaccination was an independent protective factor. Furthermore, aHRs for CKD/dialysis were 0.71 (0.65−0.77)/0.77 (0.68−0.87), 0.57 (0.52−0.61)/0.69 (0.56−0.70), and 0.30 (0.28−0.33)/0.28 (0.24−0.31) in the patients who received 1, 2−3, and ≥4 vaccinations during the follow-up period, respectively. This population-based cohort study demonstrated that influenza vaccination exerts a dose-dependent and synergistic protective effect against CKD in the patients with T2DM with associated risk factors.

Effectiveness of influenza and pneumococcal vaccines on chronic obstructive pulmonary disease exacerbations

BACKGROUND AND OBJECTIVE

Single-study evidence of separate and combined effectiveness of influenza and pneumococcal vaccination in patients with chronic obstructive pulmonary disease (COPD) is limited. To fill this gap, we studied the effectiveness of trivalent seasonal influenza vaccine (TIV) and 23-valent pneumococcal polysaccharide vaccine (PPSV23), separately and together, at preventing adverse COPD outcomes.

METHODS

Our study used a self-controlled, before-and-after cohort design to assess the effectiveness of TIV and PPSV23 in COPD patients. Patients were recruited from hospitals in Tangshan City, Hebei Province, China. Subjects self-selected into one of the three vaccination schedules: TIV group, PPSV23 group and TIV&PPSV23 group. We used a physician-completed, medical record-verified questionnaire to obtain data on acute exacerbations of COPD (AECOPD), pneumonia and related hospitalization. Vaccine effectiveness was determined by comparing COPD outcomes before and after vaccination, controlling for potential confounding using Cox regression.

RESULTS

We recruited 474 COPD patients, of whom 109 received TIV, 69 received PPSV23 and 296 received TIV and PPSV23. Overall effectiveness for preventing AECOPD, pneumonia and related hospitalization were respectively 70%, 59% and 58% in the TIV group; 54%, 53% and 46% in the PPSV23 group; and 72%, 73% and 69% in the TIV&PPSV23 group. The vaccine effectiveness without COVID-19 non-pharmaceutical intervention period were 84%, 77% and 88% in the TIV group; 63%, 74% and 66% in the PPSV23 group; and 82%, 83% and 91% in the TIV&PPSV23 group.

CONCLUSION

Influenza vaccination and PPSV23 vaccination, separately and together, can effectively reduce the risk of AECOPD, pneumonia and related hospitalization. Effectiveness for preventing AECOPD was the greatest.

Influenza Vaccination and Risk of Stroke in Women With Chronic Obstructive Pulmonary Disease: A Nationwide, Population-Based, Propensity-Matched Cohort Study

BACKGROUNDS

The risk of stroke is higher among patients with chronic obstructive pulmonary disease (COPD) than among the healthy population. Moreover, women generally have worse long-term stroke outcomes than men.

METHODS

The data of 6681 women with COPD (aged ≥ 65 years) registered in Taiwan's National Health Insurance Research Database were retrospectively analyzed from January 1, 2001 to December 31, 2011. After 1:1 propensity score matching, the patients were divided into vaccinated and unvaccinated groups.

RESULTS

In total, 5102 women were enrolled. The vaccinated group had a significantly lower risk of total, hemorrhagic, and ischemic stroke than the unvaccinated group (adjusted hazard ratio [aHR]: 0.60, 95% confidence interval [CI]: 0.54-0.67; aHR: 0.59, 95% CI: 0.43-0.83; and aHR: 0.59, 95% CI: 0.52-0.68, respectively). A lower risk of stroke was observed among the women aged 65-74 and ≥75 years, and the association was dose-dependent in all types of stroke (aHR: 1.08, 95% CI: 0.92-1.26; aHR: 0.70, 95% CI: 0.60-0.82; and aHR: 0.32, 95% CI: 0.26-0.38 for those vaccinated 1, 2 to 3, and ≥4 times, respectively, during the follow-up period). Women with a CHA2DS2-VASc score (conditions and characteristics included congestive heart failure, hypertension, diabetes, stroke, vascular disease, age, and sex) of 2-3 and ≥4 had a significantly lower risk of ischemic stroke while receiving more vaccinations. A smaller significant lower risk of hemorrhagic stroke after more than 4 times of vaccination was noted in the women with a CHA2DS2-VASc score of ≥4. Both interrupted and non-interrupted vaccination was associated with lower risk of stroke occurrence.

CONCLUSION

Influenza vaccination is associated with a lower risk of total, hemorrhagic, and ischemic stroke among women with COPD, and the association is dose-dependent. However, the findings may be limited by unmeasurable confounders. Further investigations on this subject are warranted.

The Association between Influenza Vaccination and Stroke Risk in Patients with Hypertension: A Nationwide Population-Based Study

There is evidence of strong association between influenza infections and stroke; however, the influenza vaccination and its effect on strokes is currently unclear. In the present study, Taiwan’s National Health Insurance Database was used in obtaining data for study subjects 55 years and older diagnosed with hypertension (n = 59,251; 25,266 vaccinated and 33,985 unvaccinated subjects) from 2001–2012. Propensity scores were calculated using a logistic regression model to determine the effects of vaccination by accounting for covariates that predict receiving the intervention (vaccine). A time-dependent Cox proportional hazard model was used to calculate the hazard ratios (HRs) for stroke in vaccinated and unvaccinated patients. Influenza vaccination was associated with a 42%, 40% and 44% stroke risk reduction in the entire cohort for all seasons, the influenza season and the non-influenza season, respectively (Adjust hazard ratio [aHR]: 0.58, 95% confidence interval [CI]: 0.56–0.61; aHR: 0.60, 95% CI: 0.56–0.63; aHR: 0.56, 95% CI: 0.52–0.60, for all seasons, the influenza season and the non-influenza season, respectively). The effect of risk reduction by vaccination also revealed a trend of dose dependency. Among subjects between 55 to 64 years old with four or more vaccinations during the study period, there is a 73% risk reduction for stroke during the non-influenza season (aHR: 0.27, 95% CI: 0.20–0.34). In conclusion, the influenza vaccination exerts dose-dependent and synergistic protective effects against stroke in individuals 55 years and older with hypertension.

The Implications of Vaccines in Older Populations

Mean longevity is increasing worldwide, with major consequences for public health worldwide, as the global population of adults aged over 65 years now exceeds the number of children under 5 for the first time in history. The ageing process over the life course is extremely heterogeneous, and it will be important to promote and enhance healthy ageing worldwide. Vaccination is a key player in the healthy ageing process, both at the individual and the community level. We review here the contribution of vaccines to individual and community health. At an individual level, we highlight the prevention of infectious diseases, as well as other, less well-known benefits of vaccination, such as modulation of the inflammatory process. We then underline the importance of vaccination in achieving herd immunity and reducing the transmission of pathogens in the community. Finally, at a community level, another important benefit of vaccination is the reduction in antimicrobial resistance. Taken together, these effects contribute to ensuring the best health, for the greatest number, for the longest time possible.

Effect of influenza vaccination on the outcomes of hospitalization for kidney disease in a geriatric population: A propensity-score matched study

Background and aims

The effects of influenza vaccination (IV) on the outcomes of patients with kidney disease (KD) are not completely understood. We aimed to evaluate and compare the outcomes during admission of KD between elderly patients who did or did not receive an IV within the previous 12 months.

Methods

We used health insurance research data in Taiwan and conducted a population-based cohort study that included 22,590 older people aged ≥ 65 years who were hospitalized for KD in 2008–2013. We performed propensity score matching (case-control ratio 1:1) to select 4386 eligible IV recipients and 4386 nonrecipient controls for comparison. The adjusted odds ratios (ORs) with 95% confidence intervals (CIs) of IV associated with complications and mortality during KD admission were calculated using multivariable logistic regression analyses.

Results

During hospitalization for KD, IV was significantly associated with lower risks of 30-day in-hospital mortality (OR 0.56, 95% CI 0.39–0.82), septicemia (OR 0.77, 95% CI 0.68–0.87), and intensive care (OR 0.85, 95% CI 0.75–0.96). Additionally, IV recipients had a shorter length of hospital stay and lower medical expenditure than nonrecipients. Subgroup analyses further showed that the association of IV with reduced adverse events was confined to patients aged ≥ 75 years.

Conclusions

Previous IV was associated with reduced risks of complications and mortality and in elderly patients hospitalized for KD. We raised the possibility and suggested the need to promote IV for this susceptible population of patients with KD.

Recommendations of the Italian society for infectious and tropical diseases (SIMIT) for adult vaccinations

Vaccination prevents 2-3 million deaths worldwide every year. Nevertheless, vaccine-preventable diseases (VPDs) still cause a considerable number of deaths especially in subjects belonging to "risk groups." These are represented by older adults, immunocompromised individuals and all subjects with underlying chronic medical conditions (cardiovascular, pulmonary, renal and liver chronic diseases, diabetes, immunodeficiency disorders). They have a weaker immune system and, if infected, are more likely to develop severe complications of their condition or of the preventable-infectious disease. This document summarizes the recommendations for vaccination of the main Global Institutional Organizations and analyses the risks of comorbidities associated with infectious disease and the benefits of vaccination for each specific group. The document provides a clear, practical and authoritative guide to adult vaccination.

Influenza Vaccination and the Risk of Ventricular Arrhythmias in Patients With Chronic Obstructive Pulmonary Disease: A Population-Based Longitudinal Study

Backgrounds: Influenza vaccination could decrease the risk of major cardiac events in patients with chronic obstructive pulmonary disease (COPD). However, the effects of the vaccine on decreasing the risk of ventricular arrhythmia (VA) development in such patients remain unclear. Methods: We retrospectively analyzed the data of 18,658 patients with COPD (≥55 years old) from the National Health Insurance Research Database from January 1, 2001, to December 31, 2012. After a 1:1 propensity score matching by the year of diagnosis, we divided the patients into vaccinated and unvaccinated groups. Time-varying Cox proportional hazards regression was applied to assess the time to event hazards of influenza vaccination exposure. Results: The risk of VA occurrence was significantly lower in the vaccinated group during influenza season and all seasons [adjusted hazard ratio (aHR): 0.62, 95% CI: 0.41-0.95; aHR: 0.69, 95% CI: 0.44-1.08; and aHR: 0.65, 95% CI: 0.48-0.89, in the influenza season, non-influenza season, and all seasons, respectively]. Among patients with CHA₂DS₂-VASc scores (conditions and characteristics included congestive heart failure, hypertension, diabetes, stroke, vascular disease, age, and sex) of 2-3, receiving one time and two to three times of influenza vaccination were associated with lower risk of VA occurrence in all seasons (aHR: 0.28, 95% CI: 0.10-0.80; aHR: 0.27, 95% CI: 0.10-0.68, respectively). Among patients without stroke, peripheral vascular disease, and diabetes, a lower risk of VA occurrence after receiving one and two to three times vaccination was observed in all seasons. Among patients with a history of asthma and patients without a history of heart failure, ischemic heart disease, angina hypertension, or renal failure, a significantly lower risk of VA occurrence was observed after the first time of vaccination in all seasons. Conclusions: Influenza vaccination may be associated with lower risks of VA among patients with COPD aged 55-74. Further investigation is still needed to resolve this clinical question.

Healthy Ageing and Vaccines: Application of the P4 Medicine Concept to Immunizations

In today's tormented world, it appears useful to take advantage of communication channels to promote life-course immunization and affirm its major role in healthy ageing. Instead of developing the argument of chronological age, we demonstrate the life-course principle here based on the P4 medicine concept. Are vaccines "preventive, personalized, predictive, and participatory?" Based on detailed analysis of research findings, we successively demonstrate the seminal role of vaccines on preventable infectious diseases, post-sepsis functional decline, non-communicable diseases (cardio-neuro-vascular, respiratory, and renal diseases), community protection, antimicrobial resistance, and perhaps even old-age dementia. Healthy ageing and the promotion of immunization are closely dependent on health literacy and provision of information by skilled health-care professionals. However, personal autonomy and individual freedom are influenced by psycho-cognitive hurdles (cultural approaches, beliefs, emotions, and behaviours), the opinions of the public/family/friends, and the increasing role of social media, which challenges scientific evidence. A similar phenomenon exists when dealing with the issue of healthy ageing, whose success depends greatly on life-course immunization.

Vaccination in Older Adults: An Underutilized Opportunity to Promote Healthy Aging in India

Over the last 50 years, the Indian population aged 50 years and above (older adults) has quadrupled and is expected to comprise 404 million people in 2036, representing 27% of the country's projected population. Consequently, the contribution of chronic disease to older adults' total burden of diseases in India is likely to escalate. Disease burden is notably amplified by immunosenescence, a deterioration of the immune system that develops with age, leading to increasing susceptibility to infectious diseases and other comorbidities. Older adults with infectious diseases have a higher incidence and likelihood of life-threatening comorbidities such as coronary artery disease, arrhythmia, stroke, myocardial infarction, hypertension, dyslipidemia, and diabetes mellitus. Therefore, immunization of older adults through vaccination might greatly reduce the burden imposed by vaccine preventable infectious diseases in this population. Here, we review evidence relevant to the disease burden among adults aged ≥ 50 years in India, and existing vaccination recommendations. Furthermore, we suggest a set of routine vaccinations for healthy older adults in India. There is a clear mandate to recognize the contributions of older adults to society and embrace strategies promoting healthy aging, which is described by the World Health Organization as the process of developing and maintaining functional ability and well-being in older age. Increasing vaccination awareness and coverage among older adults is an important step in that direction for India.

The impact of influenza vaccination on cardiovascular disease

Influenza infection has been identified as a triggering or exacerbating factor for cardiovascular events. To analyse the effect of influenza vaccination on cardiovascular disease, a systematic search of studies published between 2009-2019 was conducted. All the studies that evaluated the effect of vaccination against influenza on cardiovascular events and their outcome were considered. Finally, 30 of the 1147 identified studies were included. These studies show a protective effect of the influenza vaccine on the development of cardiovascular events (myocardial infarction, cerebrovascular accidents, atrial fibrillation, and heart failure) and on the worsening of these conditions. Furthermore, the data showed that vaccinated patients have a lower risk of death from cardiovascular pathologies. Influenza vaccination is therefore an effective measure in the prevention of cardiovascular diseases both in patients with established cardiovascular disease and in the population without previous coronary pathology.

Immune Mechanisms in Cardiovascular Diseases Associated With Viral Infection

Influenza virus infection causes 3-5 million cases of severe illness and 250,000-500,000 deaths worldwide annually. Although pneumonia is the most common complication associated with influenza, there are several reports demonstrating increased risk for cardiovascular diseases. Several clinical case reports, as well as both prospective and retrospective studies, have shown that influenza can trigger cardiovascular events including myocardial infarction (MI), myocarditis, ventricular arrhythmia, and heart failure. A recent study has demonstrated that influenza-infected patients are at highest risk of having MI during the first seven days of diagnosis. Influenza virus infection induces a variety of pro-inflammatory cytokines and chemokines and recruitment of immune cells as part of the host immune response. Understanding the cellular and molecular mechanisms involved in influenza-associated cardiovascular diseases will help to improve treatment plans. This review discusses the direct and indirect effects of influenza virus infection on triggering cardiovascular events. Further, we discussed the similarities and differences in epidemiological and pathogenic mechanisms involved in cardiovascular events associated with coronavirus disease 2019 (COVID-19) compared to influenza infection.

Prevalence of influenza and pneumococcal vaccination in chronic obstructive pulmonary disease patients in association with the occurrence of acute exacerbations

Background

Based on current evidence, vaccination is recommended against the influenza virus and pneumococcus to avoid serious acute exacerbations in patients with chronic obstructive pulmonary disease (COPD), but the rate of their vaccination coverage is still suboptimal. To determine the prevalence and effectiveness of influenza and pneumococcal vaccination in COPD patients, and to prove its hypothetical association with the decreasing number of acute exacerbations.

Methods

We conducted a retrospective, population-based cohort study. Influenza and pneumococcal vaccination history were collected from 250 patients selected by simple random sampling from all COPD patients in Budapest at the Department of Pulmonary Rehabilitation of the National Koranyi Institute of Pulmonology between 01 January 2019 and 01 June 2019. Inclusion criteria were the following: age 40 years and diagnosis of COPD. Odds ratios (ORs) were evaluated based on the occurrence of acute exacerbations during the preceding year.

Results

The average age was 66.62 (±8.34) years, 67.30 (±8.54) for males, and 66.09 (±8.16) for females. Man:woman ratio: 43.6%:56.4% in total. Overall prevalence of influenza vaccination was 23.6%, and the pneumococcal vaccination rate was 10.8% among COPD patients. Influenza and pneumococcal vaccination showed a significant protective effect and reduced the occurrence of exacerbations in the following year, influenza vaccination OR: 2.11 (95% CI: 0.88-5.02), pneumococcal vaccination OR: 1.06 (95% CI: 0.84-1.34), when taking both vaccination: OR: 2.37 (95% CI: 1.39-4.08).

Conclusions

We found association between influenza and pneumococcal vaccination and the reduced risk of hospitalization due to exacerbations in the ensuing year. The prevalence of vaccination is significantly below the optimal level.

Effects of influenza vaccination on the risk of cardiovascular and respiratory diseases and all-cause mortality

BACKGROUND

Influenza vaccination is a simple strategy recommended for the prevention of influenza infection and its complications. This meta-analysis aimed to provide current supportive evidence for the breadth and validity of the observed protective effects of influenza vaccination on cardiovascular and respiratory adverse outcomes and all-cause mortality in older adults and in general adult population.

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Library to identify all published studies comparing influenza vaccination with placebo from the database inception to November 11, 2018. These included studies reporting the associations of influenza vaccination with the risk of aforementioned adverse outcomes.

RESULTS

The pooled adjusted relative risks among influenza-vaccinated people relative to unvaccinated people for the outcomes of interest were 0.74 (95 % confidence interval [CI] = 0.70-0.78) for cardiovascular diseases (63 studies), 0.82 (95 % CI = 0.75-0.91) for respiratory diseases (29 studies), and 0.57 (95 % CI = 0.51-0.63) for all-cause mortality (43 studies). We performed subgroup analysis of age, sex, and region/country and found that these protective effects were evident in the general adult population and particularly robust in older adults and in those with pre-existing specific diseases.

CONCLUSION

Influenza vaccine is associated with a significant risk reduction of cardiovascular and respiratory adverse outcomes as well as all-cause mortality. Such a preventative measure can benefit the general population as well as those in old age and with pre-existing specific diseases.

Influenza Vaccination and Hospitalization Outcomes Among Older Patients With Cardiovascular or Respiratory Diseases

BACKGROUND

Influenza vaccination has been suggested to protect against death and recurrent events among patients with cardiovascular disease or chronic obstructive respiratory disease, but there is limited evidence in older adults, who have higher risks of influenza-associated hospitalization and mortality.

METHODS

Patients aged ≥60 years hospitalized for cardiovascular or respiratory diseases from the Beijing Urban Employee Basic Medical Insurance database during 3 influenza seasons (2013-2014 through 2015-2016) were pooled to estimate the effects of influenza vaccination on hospitalization outcomes. Vaccination status was ascertained through cross-referencing the Beijing Elderly Influenza Vaccination database. The summer months (June-August) were used as a reference period to adjust for unmeasured confounders during influenza seasons.

RESULTS

After adjustment for both measured and unmeasured confounders, influenza vaccination was associated with lower risks of in-hospital deaths among patients hospitalized for cardiovascular (odds ratio [95% confidence interval], 0.85 [.68-1.06]) or respiratory diseases (0.66 [.54-.82]). Influenza vaccination was associated with a lower risk of readmission among patients with cardiovascular (odds ratio [95% confidence interval], 0.81 [.69-.95]) but not respiratory diseases (1.12 [.92-1.35]). Influenza vaccination was also associated with lower direct medical costs, but not with length of stay.

CONCLUSIONS

Influenza vaccination protected against hospitalization outcomes among older adults with cardiovascular or respiratory diseases.

Cardiovascular-targeted patient education and uptake of influenza vaccination in elderly patients

BACKGROUND

Elderly patients are especially vulnerable to influenza and its complications but their vaccination coverage remains unsatisfactory.

DESIGN

Prospective study of hospitalized or ambulatory patients ≥65 years of age. A questionnaire on influenza vaccination was followed by short physician-administered verbal instruction on risk of 'heart-attack and stroke' following influenza, ameliorated by vaccination.

RESULTS

Most patients (n = 100) had cardiovascular risk-factors, many had prior vascular disease. In 2018, 53 % did not intend to be vaccinated. None were aware of the association between influenza and risk of vascular events but when asked again ≤7 days after the intervention 34/53 (64 %) stated they will shortly get vaccinated. Charts of 27/34 recorded actual influenza vaccination when examined six weeks later (51 % of 'unwilling' patients). Together with the patients already planning to be vaccinated (47 + 27/100) the current target of 70 % vaccinated can be surpassed.

CONCLUSION

Pending confirmation by a larger RCT, informing elderly patients of the substantial risk of vascular events following influenza and its modification by vaccination may constitute a simple, effective, costless and time-frugal method of changing many patients' often-negative attitudes towards seasonal influenza vaccination. The resulting increased vaccine uptake in vulnerable elderly patients, may improve their influenza-associated morbidity and mortality.

PRACTICE IMPLICATIONS

Providers discussing seasonal influenza vaccination with their patients could inform them of the substantially increased risk of myocardial infarction and ischemic stroke associated with acute influenza to overcome vaccine hesitancy.

Precision Medicine and Vaccination of Older Adults: From Reactive to Proactive (A Mini-Review)

As populations age globally, the health of older adults is looming larger on the agendas of public health bodies. In particular, the priority is to ensure that older adults remain healthy, independent, and engaged in their communities. In other words, ensuring that increasing life spans are matched by increasing "health spans," meaning years spent in good health. Chronic conditions such as cancer or respiratory and cardiovascular diseases account for the bulk of the disease burden in older adults, and the consensus is that these can best be tackled by effective primary prevention. However, given the diverse nature of older populations, whose prior health experiences can be complicated by multi-morbidity and poly-pharmacy, effective primary prevention can be challenging. One approach that is gaining momentum is what is called "precision" or P4 medicine. The acronym stands for "predictive, personalized, preventive, participatory" medicine, and is based on the premise that preventing disease is better than treating it. However, effective prevention requires the ability to predict disease risk for a given patient, the tailoring of treatment to their circumstances, and their consent for or participation in the offered treatment. A P4 approach may seem counter-intuitive, given that vaccination is generally considered a public health intervention. However, in this article, we discuss the application of P4 medicine as a complement to planning the vaccination of older individuals, with a special focus on the important role that vaccine-preventable infections play in the burden of non-communicable disease.

Effect of annual influenza vaccination on reducing lung cancer in patients with chronic obstructive pulmonary disease from a population-based cohort study

Chronic obstructive pulmonary disease (COPD) patients are at a higher risk of development of lung cancer. Frequent exacerbations of COPD trigger the disease course to chronic inflammation which likely plays a role in the pathogenesis of lung cancer. Previous studies showed influenza virus infection is one of important causes for exacerbations of COPD. Therefore, the aim of this study was to know whether influenza vaccination could reduce the incidence of lung cancer in patients with COPD.This cohort study enrolled patients (≥55 years old) with a recorded diagnosis of COPD between January 1, 2000 and December 31, 2012 by using the Taiwan Health Insurance Database. A propensity score was calculated to reduce vaccine therapy selection bias. Cox proportional hazard regressions were used to investigate the association between the influenza vaccination and lung cancer incidence after adjusting for known confounding factors. Besides, we categorized the patients into 4 groups according to vaccination status (unvaccinated, total number of vaccinations: 1, 2-3, ≥4) to evaluate the dose-dependent effect on reducing lung cancer occurrence of lung cancer in COPD patients.Our study comprised of 28,752 eligible individuals from the COPD cohort database. Among them, 51% (14,630) received influenza vaccination; the rest (49%) of the COPD patients did not receive influenza vaccination. We observed that COPD patients receiving influenza vaccination had a lower risk of lung cancer (adjusted HR = 0.40, 95% CI (0.35-0.45), P < .001). We also founded comparable protective effect in both sexes and all age groups (55-64, 65-74, ≥75) regardless of influenza seasonality. Furthermore, dose-dependent protective effect could be seen after stratifying patients according to the total number vaccinations, the adjusted HRs for lung cancer risk were 0.48 (0.40-0.54) and 0.24 (0.20-0.29) for patients who received 2 to 3 and ≥4 vaccinations during the follow-up period.This population-based cohort study demonstrated that annual influenza vaccination administration could reduce incidence of lung cancer in COPD patients.

Impact of influenza vaccination on healthcare utilization - A systematic review

INTRODUCTION

Although a vaccine-preventable disease, influenza causes approximately 3-5 million cases of severe illness and about 290,000-650,000 deaths worldwide, which occur primarily among people 65 years and older. Nonetheless, prevention of influenza and its complications rely mainly on vaccination. We aimed to systematically evaluate influenza vaccine effectiveness at reducing healthcare utilization in older adults, defined as the reduction of outpatient visits, ILI and influenza hospitalizations, utilization of antibiotics and cardiovascular events by vaccination status during the influenza season.

METHODS

We searched MEDLINE, EMBASE, CINAHL, Cochrane Library and considered any seasonal influenza vaccine, excluding the pandemic (2009-10 season) vaccine. Reviewers independently assessed data extraction and quality assessment.

RESULTS

Of the 8308 citations retrieved, 22 studies were included in the systematic review. Overall, two studies (9%) were deemed at moderate risk of bias, thirteen (59%) at serious risk of bias and seven (32%) at critical risk of bias. For outpatient visits, we found modest evidence of protection by the influenza vaccine. For all-cause hospitalization outcomes, we found a wide range of results, mostly deemed at serious risk of bias. The included studies suggested that the vaccine may protect older adults against influenza hospitalizations and cardiovascular events. No article meeting our inclusion criteria explored the use of antibiotics and ILI hospitalizations. The high heterogeneity between studies hindered the aggregation of data into a meta-analysis.

CONCLUSION

The variability between studies prevented us from drawing a clear conclusion on the effectiveness of the influenza vaccine on healthcare utilization in older adults. Overall, the data suggests that the vaccine may result in a reduction of healthcare utilization in the older population. Further studies of higher quality are necessary.

Adult vaccination as part of a healthy lifestyle: moving from medical intervention to health promotion

As the global population ages, there is concern about the effect of an increased proportion of older individuals on the economic sustainability of healthcare systems and the social effects of an older society. Health authorities and advocacy groups in countries at the forefront of this trend are now developing strategies to ameliorate the social and financial effects of an ageing population. There is broad agreement that for both society and for the individuals, it is important to ensure that increasing lifespans are matched with increased "healthspans" - the number of years spent in good health. There is also growing consensus that vaccination is one of the tools that can play an important role in improving adult health - though currently vaccination coverage is often poor. This review focuses on two issues that consistently appear to be associated with under-vaccination: the low awareness of risk (and potential consequences) for vaccine-preventable diseases and a poor understanding of the value of improved vaccination coverage for adults. We suggest that understanding of vaccination as a health-promoting activity, rather than a medical intervention designed to prevent the spread of a specific pathogen - is a crucial step to improve vaccination uptake among adults (see Supplementary video abstract ). Key messages As populations age globally, we are seeing an increasing burden of vaccine-preventable disease in adults. Adult vaccination against some common diseases has been shown to dramatically improve health and quality of life for older people. Despite the attested benefits, vaccination coverage is almost always poor in adults, even in countries where access is free at point of care. In this article, we discuss what appears to a neglected issue in adult vaccination, that of personal autonomy. We argue that adult vaccination will only be successful if it respects individual autonomy and that this requires treating the choice to vaccinate as a public health issue akin to smoking cessation, exercise and healthy diet.

Insights about the economic impact of chronic obstructive pulmonary disease readmissions post implementation of the hospital readmission reduction program

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) affects over 12 million adults in the United States and is the third leading cause of 30-day readmissions. COPD is costly with almost $50 billion in direct costs annually. Total COPD costs can be up to double the identified direct costs because of comorbid disease and numerous indirect costs such as absenteeism. Acute exacerbations of COPD (AECOPD) are responsible for up to 70% of COPD-related healthcare costs; hospital readmissions alone account for over $15 billion annually. In this review, we aim to describe insights about the economic impact of COPD readmissions based on articles published over the last 18 months.

RECENT FINDINGS

Interventions aimed at reducing readmission, particularly those using interdisciplinary teams with bundled care interventions, were uniformly successful at improving the quality of care provided and demonstrating improved process measures. However, success at reducing readmissions and cost savings based on these interventions varied across the studies.

SUMMARY

The literature to date points to factors and conditions that may place patients at higher risk of readmissions and may lead to higher costs. Interventions aimed at reducing readmissions after index admissions for AECOPD have demonstrated variable results. Most interventions did not reflect cost-based analyses.

Influenza Vaccination and Incident Tuberculosis among Elderly Persons, Taiwan1

Experimental studies have demonstrated that influenza vaccination may protect against tuberculosis (TB) through a Th17 response. This nationwide cohort study aimed to evaluate the association of influenza vaccination with incident TB among elderly persons in Taiwan. This 2005–2012 study included 99,982 elderly persons (64,290 vaccinated and 35,692 unvaccinated) from the Taiwan National Health Insurance Research Database. During the 738,367 person-years of follow-up, 1,141 (1.14%) persons had incident TB. The cumulative incidences of TB were 145.2 cases/100,000 person-years among vaccinated elderly persons and 175.5 cases/100,000 person-years among unvaccinated elderly persons (p = 0.002). The time-dependent Cox proportional hazards model revealed that influenza vaccination was an independent protective factor for incident TB. Our results suggest that influenza vaccination is associated with a lower risk of incident TB among elderly persons in Taiwan. Further investigation of biologic mechanisms is warranted.

Challenges in adult vaccination

Life-long primary prevention interventions beginning and continuing throughout an individual's lifetime are increasingly seen as key to meeting the global healthcare challenges that accompany demographic changes - a concept referred to as "Healthy aging". In this perspective, vaccination is seen as part of a triad, together with healthy diet and exercise. Current adult vaccine coverage is lower than target vaccination rates in most developed countries, and so vaccine preventable diseases continue to present a substantial burden on health and healthcare resources, especially in older individuals. In part, this is due to lack of knowledge and understanding of the benefits of vaccination, inconsistent recommendations by providers and uncertainties about cost benefits. However, lower vaccine effectiveness in older adults plays a part, and new vaccines with novel characteristics to improve effectiveness in older adults are required. A life-course immunization approach to ensure optimal vaccine uptake across adults of all ages can be expected to reduce morbidity and mortality in later life. To achieve this, greater emphasis on public and healthcare provider education is necessary, based on appropriate economic analyses that demonstrate the overall value of vaccination. This article introduces the technical, economic, political and demographic issues that make establishing effective adult vaccination programs such a difficult, but pressing issue, and outlines some of the steps that are now being taken to address them. Key messages Life-long preventive activities that start and continue throughout life are essential, especially as the world's population is "getting older". This "Healthy aging" approach includes not only healthy diet and physical exercise; vaccination is critical in reducing some infectious diseases and their complications. Many adults, especially older adults (who have lower immunity than younger people) develop infections such as influenza and shingles that could potentially be prevented through vaccination. This review provides a perspective on the challenges in delivering a life-course immunization program. While some vaccines are less effective in older people, newer vaccines have been developed which provide stronger and longer protection in older patients than standard existing vaccines. However, the benefits of vaccination can only be realized if the vaccines are recommended and used. For that purpose, greater education of patients and their healthcare providers is necessary. Better knowledge of vaccines and making sure that all adults are up to date with all their recommended vaccines is an essential part of "Healthy aging". This should prevent not only vaccine-preventable diseases but also reduce the risk of complications in later life.

Risk of acute coronary syndrome in patients with cervical spondylosis

BACKGROUND AND AIMS

Cervical spondylosis (CS) is reported to be associated with increased sympathetic activity and hypertension. However, the cardiovascular (CV) outcomes of patients with CS are largely unknown.

METHODS

A national insurance claims dataset of 22 million enrollees in Taiwan during 1999-2010 was used as the research database. We identified 27,948 patients with CS and age-, sex-, and comorbidity-matched controls. By using multivariate logistic regression analysis after adjustment for potential cardiovascular (CV) confounders, we calculated odds ratios (ORs) with 95% confidence intervals (CIs) to quantify the association between CS and acute coronary syndrome (ACS).

RESULTS

A total of 744 ACS events were identified among the 27,948 patients with CS. The overall incidence of ACS was 4.27 per 1000 person-years in the CS cohort and 3.90 per 1000 person-years in the non-CS cohort, with an adjusted hazard ratio (aHR) of 1.13 (95% CI = 1.08-1.18). The aHRs of ACS were 1.08 (95% CI = 1.03-1.15) in the CS cohort without myelopathy and 1.20 (95% CI = 1.13-1.28) in the CS cohort with myelopathy, compared with the non-CS cohort. Compared with patients with CS without neurological signs, patients with CS receiving rehabilitation exhibited a 0.67 aHRs of ACS (95% CI = 0.59-0.76), whereas those with neurological signs receiving spinal decompression exhibited 0.73 aHRs of ACS (95% CI = 0.63-0.84).

CONCLUSIONS

CS is associated with an increased risk of ACS. Receiving treatment for CS, either rehabilitation or spinal decompression, is associated with less risk of ACS.

Influenza vaccine effectiveness among high-risk groups: A systematic literature review and meta-analysis of case-control and cohort studies

Vaccination represents the most effective intervention to prevent infection, hospitalization and mortality due to influenza. This meta-analysis quantifies data reporting influenza vaccine effectiveness (VE) on influenza visits and hospitalizations of case-control and cohort studies among high-risk groups.

A systematic literature review including original articles published between 2007 and 2016, using a protocol registered on Prospero with No. 42017054854, and a meta-analysis were conducted.

For 3 high-risk groups (subjects with underlying health conditions, pregnant women and health care workers) only a qualitative evaluation was performed. The VE quantitative analysis demonstrated a clear significant overall effect of 39% (95%CI: 32–46%) for visits and 57% (95%CI: 30–74%) for hospitalization among children. Considering the elderly influenza VE had a clear effect of 25% (95%CI: 6–40%) for visits and 14% (95%CI: 7–21%; p<0.001) for hospitalization.

This study showed the high VE of influenza vaccination among high-risk groups, representing a tool for public health decision-makers to develop evidence-based preventive interventions to avoid influenza outcomes.

Seasonal influenza vaccination in patients with COPD: a systematic literature review

BACKGROUND

Influenza is a frequent cause of exacerbations of chronic obstructive pulmonary disease (COPD). Exacerbations are associated with worsening of the airflow obstruction, hospitalisation, reduced quality of life, disease progression, death, and ultimately, substantial healthcare-related costs. Despite longstanding recommendations to vaccinate vulnerable high-risk groups against seasonal influenza, including patients with COPD, vaccination rates remain sub-optimal in this population.

METHODS

We conducted a systematic review to summarise current evidence from randomised controlled trials (RCTs) and observational studies on the immunogenicity, safety, efficacy, and effectiveness of seasonal influenza vaccination in patients with COPD. The selection of relevant articles was based on a three-step selection procedure according to predefined inclusion and exclusion criteria. The search yielded 650 unique hits of which 48 eligible articles were screened in full-text.

RESULTS

Seventeen articles describing 13 different studies were found to be pertinent to this review. Results of four RCTs and one observational study demonstrate that seasonal influenza vaccination is immunogenic in patients with COPD. Two studies assessed the occurrence of COPD exacerbations 14 days after influenza vaccination and found no evidence of an increased risk of exacerbation. Three RCTs showed no significant difference in the occurrence of systemic effects between groups receiving influenza vaccine or placebo. Six out of seven studies on vaccine efficacy or effectiveness indicated long-term benefits of seasonal influenza vaccination, such as reduced number of exacerbations, reduced hospitalisations and outpatient visits, and decreased all-cause and respiratory mortality.

CONCLUSIONS

Additional large and well-designed observational studies would contribute to understanding the impact of disease severity and patient characteristics on the response to influenza vaccination. Overall, the evidence supports a positive benefit-risk ratio for seasonal influenza vaccination in patients with COPD, and supports current vaccination recommendations in this population.

Influenza vaccination reduces hemorrhagic stroke risk in patients with atrial fibrillation: A population-based cohort study

PURPOSE

The risk of hemorrhagic stroke in patients with atrial fibrillation (AF) is low but the consequences of its occurrence are extremely severe. In this study, we investigated the association of influenza vaccination with the risk of hemorrhagic stroke to develop an efficient strategy for reducing this risk in patients with AF.

METHODS

In this study, data were retrieved from the Taiwan National Health Insurance Research Database. The study cohort comprised all patients who received a diagnosis of AF (n=14,454) before January 1, 2005 (index date) and were followed until December 31, 2012. Propensity scores were calculated using a logistic regression model to determine the effects of vaccination by accounting for covariates that predict receiving the intervention (vaccine). A time-dependent Cox proportional hazard model was used to calculate the hazard ratios (HRs) for hemorrhagic stroke in vaccinated and unvaccinated patients with AF.

RESULTS

The study population comprised 6570 patients who did (2547 [38.77%]) and did not receive (4023 [61.23%]) influenza vaccination. The adjusted HRs (aHRs) for hemorrhagic stroke were lower in the vaccinated patients than in the unvaccinated patients (influenza season, noninfluenza season, and all seasons: aHRs=0.97 [0.59-1.60], 0.51 [0.30-0.87], and 0.72 [0.50-1.03], respectively).

CONCLUSIONS

Influenza vaccination exerts dose-response and synergistic protective effects against hemorrhagic stroke in patients with AF who have a high risk of hemorrhagic stroke (i.e., male sex, age≥75years, Charlson comorbidity index ≥3, and hypertension) and reduces the incidence of hemorrhagic stroke.

Prevalence and burden of comorbidities in Chronic Obstructive Pulmonary Disease

The classical definition of Chronic Obstructive Pulmonary Disease (COPD) as a lung condition characterized by irreversible airway obstruction is outdated. The systemic involvement in patients with COPD, as well as the interactions between COPD and its comorbidities, justify the description of chronic systemic inflammatory syndrome. The pathogenesis of COPD is closely linked with aging, as well as with cardiovascular, endocrine, musculoskeletal, renal, and gastrointestinal pathologies, decreasing the quality of life of patients with COPD and, furthermore, complicating the management of the disease. The most frequently described comorbidities include skeletal muscle wasting, cachexia (loss of fat-free mass), lung cancer (small cell or non-small cell), pulmonary hypertension, ischemic heart disease, hyperlipidemia, congestive heart failure, normocytic anemia, diabetes, metabolic syndrome, osteoporosis, obstructive sleep apnea, depression, and arthritis. These complex interactions are based on chronic low-grade systemic inflammation, chronic hypoxia, and multiple common predisposing factors, and are currently under intense research. This review article is an overview of the comorbidities of COPD, as well as their interaction and influence on mutual disease progression, prognosis, and quality of life.

Influenza vaccination in north Indian patients with heart failure

Background

No data exists regarding the uptake of influenza vaccination in patients with heart failure (HF) in India. The present study was designed to assess the uptake, knowledge, attitude and practices of the Indian HF patients towards influenza vaccination.

Methods and results

Five-hundred patients with acute/chronic HF were approached for a personal interview and responses to an interview recorded in a pre-defined questionnaire depicting their knowledge, attitudes and practice regarding influenza vaccination. Of the 500 approached, 320 (64%, 174 male, age 3–90 years) consented to participate in the survey. Only 7.5% (n = 24) knew of influenza as an illness with adverse potential consequences for themselves or their family. Seventeen (5.3%) were aware of potentially serious nature of influenza and 40 (12.5%) knew of the availability of a vaccine against it and its local availability. However only 14 (4.4%) had actually received the vaccine 1–2 times in the past 5 years. Only 21 (6.56%) had been prescribed influenza vaccine by their respective physicians. Reasons for declining vaccination included misperceptions about safety and efficacy of the vaccine. Most of the participants, however, had not been prescribed vaccination at all.

Conclusions

Poor influenza vaccination rates in HF mandate intense efforts to improve vaccination rates.

Influenza Vaccination Reduces Dementia Risk in Chronic Kidney Disease Patients: A Population-Based Cohort Study

Taiwan has the highest prevalence of chronic kidney disease (CKD) worldwide. CKD, a manifestation of vascular diseases, is associated with a high risk of dementia. Here, we estimated the association between influenza vaccination and dementia risk in patients with CKD. Data from the National Health Insurance Research Database of Taiwan were used in this study. The study cohort included all patients diagnosed with CKD (according to International Classification of Disease, Ninth Revision, Clinical Modification codes) at healthcare facilities in Taiwan (n = 32,844) from January 1, 2000, to December 31, 2007. Each patient was followed up to assess dementia risk or protective factors: demographic characteristics of age and sex; comorbidities of diabetes, hypertension, dyslipidemia, cerebrovascular diseases, parkinsonism, epilepsy, substance and alcohol use disorders, mood disorder, anxiety disorder, psychotic disorder, and sleep disorder; urbanization level; monthly income; and statin, metformin, aspirin, and angiotensin-converting enzyme inhibitor (ACEI) use. A propensity score was derived using a logistic regression model for estimating the effect of vaccination by accounting for covariates that predict receiving the intervention (vaccine). A time-dependent Cox proportional hazard model was used to calculate the hazard ratios (HRs) of dementia among vaccinated and unvaccinated CKD patients. The study population comprised 11,943 eligible patients with CKD; 5745 (48%) received influenza vaccination and the remaining 6198 (52%) did not. The adjusted HRs (aHRs) of dementia decreased in vaccinated patients compared with those in unvaccinated patients (influenza season, noninfluenza season, and all seasons: aHRs = 0.68, 0.58, and 0.64; P < 0.0001, P < 0.0001, and P < 0.0001, respectively). In the sensitivity analysis, adjustments were made to estimate the association of age and sex; diabetes, dyslipidemia, hypertension, cerebrovascular diseases, anxiety disorder; and statin, metformin, ACEI, and aspirin use with the incidence of dementia in various models. A stronger protective effect against dementia risk was demonstrated during the noninfluenza season. Regardless of comorbidities or drug use, influenza vaccination was an independent protective factor and dose-dependently reduced the risk of dementia in CKD patients. Influenza vaccination exerts dose-response and synergistic protective effects against dementia in CKD patients with dementia risk factors by reducing the incidence of dementia.

The Effectiveness of Influenza Vaccination in Different Groups

Annual administration of the seasonal influenza vaccine, especially to persons known to be at elevated risk for developing serious complications, is the focus of current efforts to reduce the impact of influenza. The main factors influencing estimated inactivated influenza vaccine efficacy and effectiveness, the results obtained in different population groups, current vaccination strategies and the possible advantages of new vaccines are discussed. The available evidence suggests that influenza vaccines are less effective in the elderly than in young adults, but vaccination is encouraged by public health institutions due to higher mortality and complications. There is no consensus on universal vaccination of children yet economic studies suggest that yearly paediatric vaccination is cost saving. The benefits of herd immunity generated by paediatric vaccination require further study. Newer vaccines should be more and more-broadly protective, stable, easy to manufacture and administer and highly immunogenic across all population groups.

Influenza Vaccination is Associated with Lower Risk of Acute Coronary Syndrome in Elderly Patients with Chronic Kidney Disease

Elderly patients with chronic kidney disease (CKD) are at a higher risk of hospitalization for cardiovascular diseases (CVD). Previous studies have showed that influenza vaccination could reduce the risk of recurrent major cardiovascular events in patients with CVD. However, the effects of influenza vaccination on the reduction of first hospitalizations for acute coronary syndrome (ACS) in elderly patients with CKD remain unknown.We conducted a cohort study using data from the Taiwan Longitudinal Health Insurance Database 1997 to 2008. This cohort study comprised elderly patients (ages ≥55 years) with a recorded diagnosis of CKD (n = 4406) between January 1, 1999, and December 31, 2007. Each patient was followed up until the end of 2008. To minimize the selection bias of vaccine therapy, a propensity score adjustment was applied. The hazard ratio (HR) and 95% confidence interval (CI) for the association between the influenza vaccination and the occurrence of first hospitalization for ACS was evaluated by Cox proportional hazards regression. We further categorized the patients into 4 groups according to their vaccination status (unvaccinated, and total number of vaccinations: 1, 2-3, and ≥4).We found that elderly CKD patients without prior CVD history receiving influenza vaccination exhibited a lower risk of hospitalization for ACS (adjusted HR = 0.35, 95% CI 0.30-0.42; P < 0.001). We observed consistent protective effects regardless of age groups (55-64, 65-74, and ≥75), gender, and seasonality of influenza. When the patients were stratified according to the total number of vaccinations, the adjusted HRs for first ACS hospitalization were 0.62 (95% CI 0.52-0.81), 0.35 (95% CI 0.28-0.45), and 0.13 (95% CI 0.09-0.19) for patients who received 1, 2 to 3, and ≥4 vaccinations. There was a significant trend of decreasing risk of ACS hospitalization with an increasing number of vaccinations.The results of our observational study could strengthen the annual vaccination policy and physicians should be aware of missed opportunities to vaccinate elderly patients with CKD against influenza. The potential public health impact of influenza vaccination, particularly in the elderly CKD patients without a history of CVD, who are at risk for ACS, should be further explored.

Frequency and impact of confounding by indication and healthy vaccinee bias in observational studies assessing influenza vaccine effectiveness: a systematic review

Background

Evidence on influenza vaccine effectiveness (VE) is commonly derived from observational studies. However, these studies are prone to confounding by indication and healthy vaccinee bias. We aimed to systematically investigate these two forms of confounding/bias.

Methods

Systematic review of observational studies reporting influenza VE and indicators for bias and confounding. We assessed risk of confounding by indication and healthy vaccinee bias for each study and calculated ratios of odds ratios (crude/adjusted) to quantify the effect of confounder adjustment. VE-estimates during and outside influenza seasons were compared to assess residual confounding by healthy vaccinee effects.

Results

We identified 23 studies reporting on 11 outcomes. Of these, 19 (83 %) showed high risk of bias: Fourteen due to confounding by indication, two for healthy vaccinee bias, and three studies showed both forms of confounding/bias. Adjustment for confounders increased VE on average by 12 % (95 % CI: 7–17 %; all-cause mortality), 9 % (95 % CI: 4–14 %; all-cause hospitalization) and 7 % (95 % CI: 4–10 %; influenza-like illness). Despite adjustment, nine studies showed residual confounding as indicated by significant off-season VE-estimates. These were observed for five outcomes, but more frequently for all-cause mortality as compared to other outcomes (p = 0.03) and in studies which indicated healthy vaccinee bias at baseline (p = 0.01).

Conclusions

Both confounding by indication and healthy vaccinee bias are likely to operate simultaneously in observational studies on influenza VE. Although adjustment can correct for confounding by indication to some extent, the resulting estimates are still prone to healthy vaccinee bias, at least as long as unspecific outcomes like all-cause mortality are used. Therefore, cohort studies using administrative data bases with unspecific outcomes should no longer be used to measure the effects of influenza vaccination.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-1154-y) contains supplementary material, which is available to authorized users.

8th international conference on management and rehabilitation of chronic respiratory failure: the long summaries – part 1

This paper summarizes the Part 1 of the proceedings of the 8^th International Conference on Management and Rehabilitation of Chronic Respiratory Failure, held in Pescara, Italy, on 7 and 8 May, 2015. It summarizes the contributions from numerous experts in the field of chronic respiratory disease and chronic respiratory failure. The outline follows the temporal sequence of presentations.

This paper (Part 1) includes sections regarding: Advances in Asthma and COPD Therapy (Novel Therapeutic Targets for Asthma: Proteinases, Blood Biomarker Changes in COPD Patients); The problem of Hospital Re-Admission following Discharge after the COPD Exacerbation (Characteristics of the Hospitalized COPD Patient, Reducing Hospital Readmissions Following COPD Exacerbation).

Epidemiological features of influenza in Canadian adult intensive care unit patients

To identify predictive factors and mortality of patients with influenza admitted to intensive care units (ICU) we carried out a prospective cohort study of patients hospitalized with laboratory-confirmed influenza in adult ICUs in a network of Canadian hospitals between 2006 and 2012. There were 626 influenza-positive patients admitted to ICUs over the six influenza seasons, representing 17·9% of hospitalized influenza patients, 3·1/10,000 hospital admissions. Variability occurred in admission rate and proportion of hospital influenza patients who were admitted to ICUs (proportion range by year: 11·7-29·4%; 21·3% in the 2009-2010 pandemic). In logistic regression models ICU patients were younger during the pandemic and post-pandemic period, and more likely to be obese than hospital non-ICU patients. Influenza B accounted for 14·2% of all ICU cases and had a similar ICU admission rate as influenza A. Influenza-related mortality was 17·8% in ICU patients compared to 2·0% in non-ICU patients.

Avian influenza A(H5N1) and A(H9N2) seroprevalence and risk factors for infection among Egyptians: a prospective, controlled seroepidemiological study

BACKGROUND

A(H5N1) and A(H9N2) avian influenza viruses are enzootic in Egyptian poultry, and most A(H5N1) human cases since 2009 have occurred in Egypt. Our understanding of the epidemiology of avian viruses in humans remains limited. Questions about the frequency of infection, the proportion of infections that are mild or subclinical, and the case-fatality rate remain largely unanswered.

METHODS

We conducted a 3-year, prospective, controlled, seroepidemiological study that enrolled 750 poultry-exposed and 250 unexposed individuals in Egypt.

RESULTS

At baseline, the seroprevalence of anti-A(H5N1) antibodies (titer, ≥80) among exposed individuals was 2% significantly higher than that among the controls (0%). Having chronic lung disease was a significant risk factor for infection. Antibodies against A(H9N2) were not detected at baseline when A(H9N2) was not circulating in poultry. At follow-up, A(H9N2) was detected in poultry, and consequently, the seroprevalence among exposed humans was between 5.6% and 7.5%. Vaccination of poultry, older age, and exposure to ducks were risk factors for A(H9N2) infection.

CONCLUSIONS

Results of this study indicate that the number of humans infected with avian influenza viruses is much larger than the number of reported confirmed cases. In an area where these viruses are enzootic in the poultry, human exposure to and infection with avian influenza becomes more common.