Seasonal Influenza Infections and Cardiovascular Disease Mortality

Excess Mortality and Hospitalizations Associated With Seasonal Influenza in Patients With Heart Failure

BACKGROUND

Influenza virus may cause severe infection in patients with heart failure. It is known that influenza infection is associated with increased morbidity and mortality in patients with heart failure. However, less is known about the excess burden of morbidity and mortality caused by influenza infection in patients with heart failure at a population level.

OBJECTIVES

The purpose of this study was to estimate the excess burden of morbidity and mortality as determined by annual excess number of deaths and hospitalizations associated with influenza infection in patients with heart failure in Denmark.

METHODS

We collected nationwide data on weekly number of deaths and hospitalizations among patients with heart failure in Denmark and weekly estimates of influenza circulation as determined by the proportion of positive influenza samples analyzed at all Danish Hospitals. These data were correlated in a time series linear regression model, and this model was used to estimate the annual excess number of deaths and hospitalizations attributable to influenza circulation among patients with heart failure in Denmark. The model also included data on weekly mean temperature and restricted cubic spline terms to account for seasonality and trends over time.

RESULTS

Data were available from 2010 to 2018 encompassing 8 influenza seasons with an annual mean of 25,180 samples tested for influenza at Danish hospitals. Among an annual mean of 70,570 patients with heart failure, our model estimated that influenza activity was associated with an annual excess of 250 all-cause deaths (95% CI: 144-489 deaths) corresponding to 2.6% of all all-cause deaths (95% CI: 1.5%-5.1%) in patients with heart failure. Similarly, influenza activity was associated with an annual excess of 115 cardiovascular deaths (95% CI: 62-244 deaths) corresponding to 2.9% of all cardiovascular deaths (95% CI: 1.5%-6.1%). Influenza activity was also associated with an annual excess of 251 hospitalizations for pneumonia or influenza (95% CI: 107-533 hospitalizations) corresponding to 5.0% of all hospitalizations for pneumonia or influenza.

CONCLUSIONS

Our results indicate that influenza activity likely causes substantial morbidity and mortality among patients with heart failure. Notably, our study suggests that approximately 2.6% of all deaths and 5.0% of all hospitalizations with influenza or pneumonia may be attributed to influenza in patients with heart failure.

Advances in protein subunit vaccines against H1N1/09 influenza

The A/H1N1pdm09 influenza virus, which caused the 2009 pandemic, has since become a recurring strain in seasonal influenza outbreaks. Given the ongoing threat of influenza, protein subunit vaccines have garnered significant attention for their safety and effectiveness. This review seeks to highlight the latest developments in protein subunit vaccines that specifically target the A/H1N1pdm09 virus. It will also examine the structure and replication cycle of influenza A viruses and compare different types of influenza vaccines. Additionally, the review will address key aspects of H1N1 protein subunit vaccine development, such as antigen selection, protein expression systems, and the use of adjuvants. The role of animal models in evaluating these vaccines will also be discussed. Despite challenges like antigenic variability and the complexities of vaccine production and distribution, protein subunit vaccines remain a promising option for future influenza prevention efforts.

Flu Vaccination Among Patients with Noncommunicable Diseases: A Survey About Awareness, Usage, Gaps and Barriers in Europe

Purpose

People with noncommunicable diseases (NCDs) have a high risk of contracting flu and suffering from its associated complications; however, in many countries flu vaccine uptake in this group is sub-optimal. This survey assessed the knowledge, attitudes, and gaps toward vaccination in general and flu in particular among adults with NCDs in Europe.

Patients and Methods

The survey was conducted in France, Italy, Spain, Germany, Poland, Belgium, Portugal, and the Czech Republic. A structured web-based questionnaire was administered to the subjects.

Results

In total, 1106 subjects were enrolled, with 61% aged between 41 and 60 years. The main reasons for getting vaccinated were disease prevention and healthcare practitioner recommendations. Protection against infection and the risks of not receiving a vaccination was the most common vaccine information received, followed by information about possible side effects, duration of protection, and need for a booster dose. In the unvaccinated group, there was a lack of belief in the need for a flu vaccine, with a lack of recommendation from treating practitioners, and the experience of mild severity of flu being the main barriers against the vaccine. The physician remained the most preferred and tapped resource for information followed by dedicated websites. Understanding of flu vaccine benefits was particularly widespread among vaccinated patients, yet >50% wanted to know more about them. There was less clarity of the benefits of flu vaccine among unvaccinated patients; however, approximately 50% of them wanted to know more about it. Between January 2021 and December 2022, about 30% and 36% of the vaccinated and unvaccinated individuals, respectively, reported having suffered from flu.

Conclusion

Healthcare practitioners are the key influencers for people to get vaccinated. The dissemination of information about the importance of flu vaccines needs to be increased, and clear and explanatory messaging based on country-specific characteristics is important.

Mortality patterns in Dutch diabetes outpatients

AIM

Diabetes mellitus is a major cause of death. Outpatients with diabetes have more complications than patients in general practice; mortality patterns have only been studied in the total diabetes population. This study aims to assess mortality, causes, and predictors in outpatients with diabetes.

MATERIALS AND METHODS

A cohort study, included people with diabetes mellitus from the nationwide Dutch Paediatric and Adult Registry of Diabetes (DPARD) visiting diabetes outpatient clinics in 2016-2020. DPARD data were linked to Statistics Netherlands (CBS), comprising data on mortality, ethnicity and education. All-cause and cardiovascular mortality rates were estimated using Cox proportional hazard regression.

RESULTS

During a median follow-up of 3.1 years among 12 992 people with diabetes, mortality rates per 10 000 person-years were 67.7 in adult type 1 diabetes and 324.2 in type 2 diabetes. The major cause of non-cardiovascular death was malignancy. During the pandemic years of influenza (2018) and COVID (2020), mortality rates peaked. Age, smoking and an estimated glomerular filtration rate of <60 ml/min were associated with all-cause mortality. In type 2 diabetes, additional factors were male sex, body mass index <20 kg/m2, diabetes duration <1 year and hypertension.

CONCLUSIONS

Mortality among Dutch outpatients with diabetes is high. Smoking and renal failure were associated with mortality in both types. Further focus on early detection and treatment of mortality-associated factors may improve clinical outcomes.

Risk of Cardiovascular Events After Influenza: A Population-Based Self-Controlled Case Series Study, Spain, 2011-2018

This study explores the relationship between influenza infection, both clinically diagnosed in primary care and laboratory confirmed in hospital, and atherothrombotic events (acute myocardial infarction and ischemic stroke) in Spain. A population-based self-controlled case series design was used with individual-level data from electronic registries (n = 2 230 015). The risk of atherothrombotic events in subjects ≥50 years old increased more than 2-fold during the 14 days after the mildest influenza cases in patients with fewer risk factors and more than 4-fold after severe cases in the most vulnerable patients, remaining in them more than 2-fold for 2 months. The transient increase of the association, its gradient after influenza infection, and the demonstration by 4 different sensitivity analyses provide further evidence supporting causality. This work reinforces the official recommendations for influenza prevention in at-risk groups and should also increase the awareness of even milder influenza infection and its possible complications in the general population.

Associations Between Severe Influenza-Complicated Thromboembolism Events, Intensive Care Unit Stays and Mortality, and Associated Risk Factors: A Retrospective Cohort Study

The association between influenza infection and thromboembolism (TE) events, including cardiovascular events, cerebrovascular events, pulmonary embolism, and deep vein thrombosis, is supported by compelling evidence. However, there is a disparity in the risk factors that impact the outcomes of severe influenza-complicated TE in intensive care unit (ICU) patients. The objective of this study was to evaluate the outcomes of severe influenza-complicated TE in ICU patients and identify any associated risk factors.

METHODS

A retrospective cohort study was conducted, recruiting consecutive patients with TE events admitted to the ICU between December 2015 through December 2018 at our institution in Taiwan. The study included a group of 108 patients with severe influenza and a control group of 192 patients with severe community-acquired pneumonia. Associations between complicated TE, length of ICU stay, and 90-day mortality were evaluated using logistic regression analysis, and risk factors were identified using univariate and multivariate generalized linear regression analyses.

RESULTS

TE event prevalence was significantly higher in ICU patients with severe influenza than in ICU patients with severe CAP (21.3% vs. 5.7%, respectively; p < 0.05). Patients with severe influenza who developed TE experienced a significant increase in the ratio of mechanical ventilation use, length of mechanical ventilation use, ICU stay, and 90-day mortality when compared to patients without TE (all p < 0.05). The comparison of severe CAP patients with and without TE revealed no significant differences (p > 0.05). The development of thromboembolic events in patients with severe influenza or severe noninfluenza CAP is linked to influenza infection and hypertension (p < 0.05). Furthermore, complicated TE and the severity of the APACHE II score are risk factors for 90-day mortality in ICU patients with severe influenza (p < 0.05).

CONCLUSIONS

Patients with severe influenza and complicated TE are more likely to have an extended ICU stay and 90-day mortality than patients with severe CAP. The risk is significantly higher for patients with a higher APACHE II score. The results of this study may aid in defining better strategies for early recognition and prevention of severe influenza-complicated TE.

Generation of antigen-specific memory CD4 T cells by heterologous immunization enhances the magnitude of the germinal center response upon influenza infection

Current influenza vaccine strategies have yet to overcome significant obstacles, including rapid antigenic drift of seasonal influenza viruses, in generating efficacious long-term humoral immunity. Due to the necessity of germinal center formation in generating long-lived high affinity antibodies, the germinal center has increasingly become a target for the development of novel or improvement of less-efficacious vaccines. However, there remains a major gap in current influenza research to effectively target T follicular helper cells during vaccination to alter the germinal center reaction. In this study, we used a heterologous infection or immunization priming strategy to seed an antigen-specific memory CD4+ T cell pool prior to influenza infection in mice to evaluate the effect of recalled memory T follicular helper cells in increased help to influenza-specific primary B cells and enhanced generation of neutralizing antibodies. We found that heterologous priming with intranasal infection with acute lymphocytic choriomeningitis virus (LCMV) or intramuscular immunization with adjuvanted recombinant LCMV glycoprotein induced increased antigen-specific effector CD4+ T and B cellular responses following infection with a recombinant influenza strain that expresses LCMV glycoprotein. Heterologously primed mice had increased expansion of secondary Th1 and Tfh cell subsets, including increased CD4+ TRM cells in the lung. However, the early enhancement of the germinal center cellular response following influenza infection did not impact influenza-specific antibody generation or B cell repertoires compared to primary influenza infection. Overall, our study suggests that while heterologous infection or immunization priming of CD4+ T cells is able to enhance the early germinal center reaction, further studies to understand how to target the germinal center and CD4+ T cells specifically to increase long-lived antiviral humoral immunity are needed.

Role of Influenza Vaccination in Cardiovascular Disease: Systematic Review and Meta-Analysis

Influenza vaccination has shown great promise in terms of its cardioprotective effects. The aim of our analysis is to provide evidence regarding the protective effects of influenza vaccination in patients with cardiovascular disease. We conducted a systematic literature search to identify trials assessing the cardiovascular outcomes of influenza vaccination. Summary effects were calculated using a DerSimonian and Laird fixed effects and random effects model as odds ratio with 95% confidence intervals (CIs) for all the clinical endpoints. Fifteen studies with a total of 745,001 patients were included in our analysis. There was lower rates of all-cause mortality [odds ratio (OR) = 0.74, 95% CI 0.64-0.86], cardiovascular death (OR = 0.73, 95% CI 0.59-0.92), and stroke (OR = 0.71, 95% CI 0.57-0.89) in patients who received the influenza vaccine compared to placebo. There was no significant statistical difference in rates of myocardial infarction (OR = 0.91, 95% CI 0.69-1.21) or heart failure hospitalizations (OR = 1.06, 95% CI 0.85-1.31) in the 2 cohorts. In patients with cardiovascular disease, influenza vaccination is associated with lower all-cause mortality, cardiovascular death, and stroke.

Relative Effectiveness of the MF59-Adjuvanted Influenza Vaccine Versus High-Dose Influenza Vaccine in Older Adults With Influenza Risk Factors During the 2019-2020 US Influenza Season

Background

This study estimated the relative vaccine effectiveness (rVE) of the MF59-adjuvanted trivalent influenza vaccine (aTIV) versus high-dose trivalent inactivated influenza vaccine (HD-TIV) for prevention of influenza-related medical encounters (IRMEs) during the 2019-2020 United States (US) influenza season stratified by the cumulative number of influenza risk factors. A secondary objective evaluated outpatient IRMEs and influenza- and pneumonia-related hospitalizations.

Methods

This retrospective cohort study included US adults ≥65 years old vaccinated with aTIV or HD-TIV between 1 August 2019 and 31 January 2020. Electronic health records linked to claims were used to ascertain exposure, covariates, risk factors, and outcomes. Multivariable adjusted odds ratios (ORs) were derived using inverse probability of treatment-weighted samples to calculate rVEs independently for individuals with 0, ≥1, 1-2, or ≥3 risk factors.

Results

The study included 1 115 725 aTIV and 2 561 718 HD-TIV recipients. For the primary outcome of any IRME, the analysis found comparable effectiveness between aTIV and HD-TIV (rVE, 5.2% [95% confidence interval {CI}, -5.9% to 15.1%]) among those with 0 risk factors, whereas aTIV was more effective than HD-TIV among patients with ≥1, 1-2, or ≥3 risk factors (12.5% [95% CI, 10.0%-15.0%], 18.4% [95% CI, 13.7%-22.9%], and 10.4% [7.4%-13.3%], respectively). The same trends were observed for the secondary outcomes.

Conclusions

This study demonstrated comparable effectiveness of aTIV and HD-TIV among individuals with no identified risk factors and higher effectiveness of aTIV compared with HD-TIV in preventing any IRMEs, outpatient IRMEs, and influenza- or pneumonia-related hospitalizations among those with at least 1 or multiple high-risk factors in adults ≥65 years old.

Cardio-cerebrovascular adverse outcomes in patients with influenza with and without preexisting cardiovascular disease: Oral antiviral agents impact

This study aimed to compare the 2-year cardio-cerebrovascular adverse outcomes of patients with influenza with and without preexisting cardiovascular disease (preCVD) treated with oral antiviral agents in the outpatient clinic. Oral antiviral agents are routinely prescribed to treat influenza infection with a positive rapid-antigen test in the outpatient clinic; however, influenza-associated cardio-cerebrovascular outcomes have not yet been characterized in patients with preCVD treated with oral antiviral agents. Data between 2006 and 2016 were extracted from the National Health Database of South Korea. A total of 865,522 patients with influenza treated with oral antiviral agents were selected in South Korea and classified as preexisting ischemic heart disease (IHD), heart failure (HF), or atrial fibrillation (AF), and 2-year cardio-cerebrovascular outcomes were analyzed using a Cox proportional hazard regression model. Among the participants, 96,433 had preCVD (11.1%; mean age, 46 years) including IHD (86.4%), HF (23.1%), and AF (12.5%). The incidence of new-onset IHD, AF, HF, and death was similar between patients with influenza with and without preCVD. The incidences of IHD and stroke were 0.489 and 0.047 per 100-person year in the preCVD group, respectively. The incidence of cardiovascular mortality was 0.489 per 100-person year in the preCVD group, and the hazard ratio for cardiovascular mortality in the preCVD group was not significantly different from that in patients without preCVD. Based on the national health data, 2-year cardio-cerebrovascular adverse outcomes were not significantly different between patients with and without preCVD treated with oral antiviral agents.

Protecting the elderly from influenza in the context of immune system senescence. Elderly aged 65 and over are vulnerable to influenza and its associated complications.: Position paper by the Romanian Society of Gerontology and Geriatrics

Influenza affects millions globally each year, often causing severe complications, hospitalizations, and deaths, particularly among the elderly. As the global population ages, infections will pose a growing health risk. Annual vaccination remains the most effective way to prevent influenza and its complications. After the age of 65, people suffering from chronic diseases become the majority of this population category. All the data support that most of the population over 65 years old, whose immune system goes through immunosenescence, presents multimorbidity, requiring age-appropriate anti-influenza protection. The immune response to the traditional influenza vaccine has been proven to be lower in the elderly, highlighting the need for a more immunogenic vaccine specifically tailored to the elderly population group. Therefore, high-dose (HD) influenza vaccines have demonstrated their safety and are more effective in preventing influenza and its associated complications compared to standard-dose (SD) vaccines in the elderly in the context of immunosenescence. These recommendations focus on the safety, effectiveness, and efficacy of HD influenza vaccines, adapted to the elderly and available on the Romanian market, to increase the vaccination rate and, thus, protect against influenza infection and its complications. Therefore, strategies such as increased accessibility and free immunizations, as well as ensuring that flu vaccines for the elderly are prescribed without restrictions based on the number of comorbidities, should be used.

Coronary and Cerebrovascular Events and Exacerbation of Existing Conditions After Laboratory-Confirmed Influenza Infection Among US Veterans: A Self-Controlled Case Series Study

BACKGROUND

Influenza may contribute to coronary/cerebrovascular events and exacerbate underlying conditions.

METHODS

We used self-controlled case series (SCCS) design to analyze data from US Veterans ≥18 years with coronary/cerebrovascular or exacerbation event +/-1 year of lab-confirmed influenza (LCI) during 2010-2018. We estimated the incidence ratio (IR) (95% CI) of the event for risk interval (Days 1-7 post-LCI) versus control interval (all other times +/-1 year of LCI) with fixed-effects conditional Poisson regression. We included biomarker data for mediation analysis.

RESULTS

We identified 3439 episodes with coronary/cerebrovascular-related hospitalizations. IRs (95% CI) for LCI risk versus control interval were STEMI 0.6 (0.1, 4.4), NSTEMI 7.3 (5.8, 9.2), ischemic stroke 4.0 (3.0, 5.4), hemorrhagic stroke 6.2 (3.4, 11.5), and coronary spasm 1.3 (0.5, 3.0). IR significantly increased for NSTEMI and ischemic stroke among those ≥ 65 years. IR for NSTEMI and ischemic stroke dropped 26% and 10%, respectively, when white blood cell (WBC) and platelet count were considered. LCI was significantly associated with exacerbation of preexisting asthma, chronic obstructive pulmonary disease, and congestive heart failure.

CONCLUSIONS

We found significant association between LCI and hospitalization for NSTEMI, ischemic stroke, and hemorrhagic stroke, the latter possibly due to unaccounted time-varying confounding in SCCS design.

Impact of influenza vaccination history in the clinical course of older adults hospitalized with COVID-19

BACKGROUND AND PURPOSE

Some studies have shown that influenza vaccination is associated with a lower risk of SARS-CoV-2 infection; in patients with COVID-19 infection, admission to intensive care is reduced, with less need for mechanical ventilation, shorter hospital stays, and reduced mortality. This study aimed to determine if a history of annual influenza vaccination impacts the clinical course of SARS-CoV-2 infection during hospitalization.

METHODS

This was an observational, prospective, cohort study of patients older than 65 admitted to the COVID-19 unit from January to June 2021. The history of influenza vaccination over the last 5 years was assessed in each patient during hospitalization. We measured the length of hospital stay, the need for admission to the intensive care unit (ICU), the patient's oxygen requirements, complications during hospitalization, and outcome (medical discharge or death). Patients with a history of vaccination against SARS-CoV-2 were not included.

RESULTS

We analyzed 125 patients, 50.4% (n=63) with history of influenza vaccination and 49.6% (n=62) without a history of influenza vaccination. In-hospital mortality was 44.8%, higher in the unvaccinated (54.8%) population (p=0.008). ICU admission was 27% higher in vaccinated (35%) patients (p=0.05). Patients without a history of influenza vaccination had a higher prevalence of cardiac (8% vs. 5%, p=0.04) and renal complications (29% vs. 13%, p=0.02). Patients with a history of vaccination had a greater need for invasive mechanical ventilation (25.4%, p=0.02).

CONCLUSION

In this study, a history of influenza vaccination in older adults with SARS-CoV-2 infection was related to lower in-hospital mortality.

Long COVID and cardiovascular disease: a prospective cohort study

BACKGROUND

Pre-existing cardiovascular disease (CVD) or cardiovascular risk factors have been associated with an increased risk of complications following hospitalisation with COVID-19, but their impact on the rate of recovery following discharge is not known.

OBJECTIVES

To determine whether the rate of patient-perceived recovery following hospitalisation with COVID-19 was affected by the presence of CVD or cardiovascular risk factors.

METHODS

In a multicentre prospective cohort study, patients were recruited following discharge from the hospital with COVID-19 undertaking two comprehensive assessments at 5 months and 12 months. Patients were stratified by the presence of either CVD or cardiovascular risk factors prior to hospitalisation with COVID-19 and compared with controls with neither. Full recovery was determined by the response to a patient-perceived evaluation of full recovery from COVID-19 in the context of physical, physiological and cognitive determinants of health.

RESULTS

From a total population of 2545 patients (38.8% women), 472 (18.5%) and 1355 (53.2%) had CVD or cardiovascular risk factors, respectively. Compared with controls (n=718), patients with CVD and cardiovascular risk factors were older and more likely to have had severe COVID-19. Full recovery was significantly lower at 12 months in patients with CVD (adjusted OR (aOR) 0.62, 95% CI 0.43 to 0.89) and cardiovascular risk factors (aOR 0.66, 95% CI 0.50 to 0.86).

CONCLUSION

Patients with CVD or cardiovascular risk factors had a delayed recovery at 12 months following hospitalisation with COVID-19. Targeted interventions to reduce the impact of COVID-19 in patients with cardiovascular disease remain an unmet need.

TRAIL REGISTRATION NUMBER

ISRCTN10980107.

STAT1 regulates neutrophil gelatinase B-associated lipocalin induction in influenza-induced myocarditis

Influenza is a significant public health and economic threat around the world. Epidemiological studies have demonstrated a close association between influenza pandemics and cardiovascular mortality. Moreover, it has been shown that there is a decrease in cardiovascular mortality in high-risk patients following vaccination with the influenza vaccine. Here, we have investigated the role of anti-viral STAT1 signaling in influenza-induced myocarditis. Wild-type mice (C57BL/6) were infected with either influenza A/PR/8/34 or control, and cellular response and gene expression analysis from the heart samples were assessed 7 days later. The expression of interferon response genes STAT1, STAT2, Mx1, OASL2, ISG15, chemokines CCL2, CCL3, CXCL9 and CXCL10, and the frequency of neutrophils (CD45+CD11b+Ly6G+) and CD4+ T cells (CD45+CD4+) were all significantly increased in influenza-infected mice when compared to vehicle controls. These data suggest that influenza infection induces interferons, inflammatory chemokines, and cellular recruitment during influenza infection. We further investigated the role of STAT1 in influenza-induced myocarditis. The frequency of neutrophils and the levels of lipocalin 2 were significantly increased in STAT1-/- mice when compared to WT controls. Finally, we investigated the role of Lcn2 in viral-induced myocarditis. We found that in the absence of Lcn2, there was preserved cardiac function in Lcn2-/- mice when compared to WT controls. These data suggest that the absence of Lcn2 is cardioprotective during viral-induced myocarditis.

Safety, Tolerability, and Immunogenicity of aH5N1 Vaccine in Adults with and without Underlying Medical Conditions

Influenza pandemics pose a serious risk to the global population, with the potential for high morbidity and mortality. An adjuvanted H5N1 vaccine (aH5N1) has been approved for prophylaxis against the avian influenza virus H5N1, which is a likely cause of future pandemics. In this phase-III, stratified, randomized, controlled, observer-blind, multicenter study, we evaluated the safety and immunogenicity of aH5N1 in four separate groups of adults: adults 18-60 years of age who were healthy or had high-risk medical conditions and older adults ≥61 years of age who were healthy or had high-risk medical conditions. Subjects were randomly assigned to aH5N1 or the comparator, adjuvanted trivalent seasonal influenza vaccine (aTIV). Antibody responses to aH5N1 were increased in all four subgroups and, within each age stratum, largely consistent between healthy subjects and those with medical conditions. Injection-site pain was reported by 66-73% of younger and 36-42% of older-aH5N1 recipients, and fatigue and myalgia were reported by 22-41% of subjects across age and health subgroups. No serious adverse events or deaths were considered related to the study vaccine. In conclusion, aH5N1 increased antibody responses regardless of age or health status and demonstrated a clinically acceptable safety and tolerability profile.

Comorbidity of patients with noncommunicable diseases in general practice. Eurasian guidelines

Создание руководства поддержано Советом по терапевтическим наукам отделения клинической медицины Российской академии наук.

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.

Socioeconomic inequalities in cardiovascular disease: a causal perspective

Socioeconomic inequalities in cardiovascular disease (CVD) persist in high-income countries despite marked overall declines in CVD-related morbidity and mortality. After decades of research, the field has struggled to unequivocally answer a crucial question: is the association between low socioeconomic position (SEP) and the development of CVD causal? We review relevant evidence from various study designs and disciplinary perspectives. Traditional observational, family-based and Mendelian randomization studies support the widely accepted view that low SEP causally influences CVD. However, results from quasi-experimental and experimental studies are both limited and equivocal. While more experimental and quasi-experimental studies are needed to aid causal understanding and inform policy, high-quality descriptive studies are also required to document inequalities, investigate their contextual dependence and consider SEP throughout the lifespan; no simple hierarchy of evidence exists for an exposure as complex as SEP. The COVID-19 pandemic illustrates the context-dependent nature of CVD inequalities, with the generation of potentially new causal pathways linking SEP and CVD. The linked goals of understanding the causal nature of SEP and CVD associations, their contextual dependence, and their remediation by policy interventions necessitate a detailed understanding of society, its change over time and the phenotypes of CVD. Interdisciplinary research is therefore key to advancing both causal understanding and policy translation.

Relative Effectiveness of the MF59®-Adjuvanted Influenza Vaccine Versus High-Dose and Non-Adjuvanted Influenza Vaccines in Preventing Cardiorespiratory Hospitalizations During the 2019-2020 US Influenza Season

BACKGROUND

Adults ≥ 65 years of age have suboptimal influenza vaccination responses compared to younger adults due to age-related immunosenescence. Two vaccines were specifically developed to enhance protection: MF59-adjuvanted trivalent influenza vaccine (aIIV3) and high-dose egg-based trivalent influenza vaccine (HD-IIV3e).

METHODS

In a retrospective cohort study conducted using US electronic medical records linked to claims data during the 2019-2020 influenza season, we compared the relative vaccine effectiveness (rVE) of aIIV3 with HD-IIV3e and a standard-dose non-adjuvanted egg-based quadrivalent inactivated influenza vaccine (IIV4e) for the prevention of cardiorespiratory hospitalizations, including influenza hospitalizations. We evaluated outcomes in the "any" diagnosis position and the "admitting" position on the claim. A doubly robust methodology using inverse probability of treatment weighting and logistic regression was used to adjust for covariate imbalance. rVE was calculated as 100 * (1 - ORadjusted).

RESULTS

The study included 4,299,594 adults ≥ 65 years of age who received aIIV3, HD-IIV3e, or IIV4e. Overall, aIIV3 was associated with lower proportions of cardiorespiratory hospitalizations with diagnoses in any position compared to HD-IIV3e (rVE = 3.9% [95% CI, 2.7-5.0]) or IIV4e (9.0% [95% CI, 7.7-10.4]). Specifically, aIIV3 was more effective compared with HD-IIV3e and IIV4e in preventing influenza hospitalizations (HD-IIV3e: 9.7% [95% CI, 1.9-17.0]; IIV4e: 25.3% [95% CI, 17.7-32.2]). Consistent trends were observed for admitting diagnoses.

CONCLUSION

Relative to both HD-IIV3e and IIV4e, aIIV3 provided improved protection from cardiorespiratory or influenza hospitalizations.

Influenza: cause or excuse? An analysis of flu's influence on worsening mortality trends in England and Wales, 2010-19

BACKGROUND

England and Wales experienced a stagnation of previously improving life expectancy during the 2010s. Public bodies cited influenza as an important cause.

SOURCES OF DATA

We used data from the Office for National Statistics to examine mortality attributed directly to influenza and to all influenza-like diseases for the total population of England and Wales 2010-19. Several combinations of ICD-10 codes were used to address the possibility of under-counting influenza deaths.

AREAS OF AGREEMENT

Deaths from influenza and influenza-like diseases declined between 2010 and 2019, while earlier improvements in mortality from all causes of death were stalling and, with some causes, worsening. Our findings support existing research showing that influenza is not an important cause of the stalling of mortality rates 2010-19.

AREAS OF CONTROVERSY

Influenza was accepted by many as an important cause of stalling life expectancy for much of the 2010s, while few in public office have accepted austerity as a key factor in the changes seen during that time.

GROWING POINTS

This adds to the mounting evidence that austerity damaged health prior to COVID-19 and left the population more vulnerable when it arrived.

AREAS FOR DEVELOPING TIMELY RESEARCH

Future research should explore why so many in public office were quick to attribute the change in trends in overall mortality in the UK in this period to influenza, and why many continue to do so through to 2023 and to deny the key role of austerity in harming population health.

Exposome in ischaemic heart disease: beyond traditional risk factors

Ischaemic heart disease represents the leading cause of morbidity and mortality, typically induced by the detrimental effects of risk factors on the cardiovascular system. Although preventive interventions tackling conventional risk factors have helped to reduce the incidence of ischaemic heart disease, it remains a major cause of death worldwide. Thus, attention is now shifting to non-traditional risk factors in the built, natural, and social environments that collectively contribute substantially to the disease burden and perpetuate residual risk. Of importance, these complex factors interact non-linearly and in unpredictable ways to often enhance the detrimental effects attributable to a single or collection of these factors. For this reason, a new paradigm called the 'exposome' has recently been introduced by epidemiologists in order to define the totality of exposure to these new risk factors. The purpose of this review is to outline how these emerging risk factors may interact and contribute to the occurrence of ischaemic heart disease, with a particular attention on the impact of long-term exposure to different environmental pollutants, socioeconomic and psychological factors, along with infectious diseases such as influenza and COVID-19. Moreover, potential mitigation strategies for both individuals and communities will be discussed.

Influenza vaccine effect on risk of stroke occurrence: a systematic review and meta-analysis

Background

Stroke is a significant global cause of mortality and long-term disability, potentially influenced by infections that heighten systemic inflammation and thrombotic events. The full impact of influenza vaccination on stroke remains uncertain. This systematic review and meta-analysis aimed to investigate the association between influenza immunization and stroke incidence.

Methods

We searched for randomized controlled trials (RCTs), case-control, and cohort studies published in PubMed/Medline, Cochrane-Central-Register-of-Controlled-Trials (CENTRAL), and Embase until 5 December 2022, and identified articles investigating the effect of influenza vaccine on stroke occurrence. All articles were screened by two independent reviewers. We performed a meta-analysis to investigate the risk of stroke occurrence in vaccinated vs. unvaccinated individuals. The random-effects model was used in all statistical analyses.

Results

Among the 26 articles meeting our criteria, 10 were retrospective cohort studies, 9 were case-control studies, 3 were prospective cohort studies, 3 were RCTs and 1 case-series. Overall, the studies showed a significant decrease in the risk of stroke incidence/hospitalization among vaccinated patients (OR = 0.81, 95% CI [0.77-0.86], p = 0.00001). Furthermore, studies showed flu vaccine decreases the occurrence of mortality among stroke patients (OR = 0.50, 95% CI [0.37-0.68], p = 0.00001). Sub-group analysis revealed significant protective effect for patients with specific comorbidities including atrial fibrillation (OR = 0.68, 95% CI [0.57-0.81], p = 0.0001), diabetes (OR = 0.76, 95% CI [0.66-0.87], p = 0.0001), Chronic obstructive pulmonary disease (OR = 0.70, 95% CI [0.61-0.81], p = 0.00001), and hypertension (OR = 0.76, 95% CI [0.70-83], p = 0.00001).

Conclusion

The current meta-analysis further supports prior findings that influenza vaccination reduces stroke risk, particularly in patients with comorbidities. Guidelines should promote vaccination for at-risk individuals.

Cumulative incidence and mortality rate of cardiovascular complications due to laboratory-confirmed influenza virus infection: A systematic review and meta-analysis

Influenza infection is associated with cardiovascular complications that range significantly in presentation and severity. The cumulative incidence of cardiovascular complications due to laboratory-confirmed influenza, however, is not reported in the literature. We conducted a systematic review and random-effects meta-analysis to evaluate the cumulative incidence and mortality rate of influenza virus-related cardiovascular complications in hospitalized patients. We searched the PubMed and EMBASE databases for studies reporting acute myocardial infarction (AMI), heart failure (HF), arrhythmia of any kind, stroke or transient ischemic attack (TIA), and myocarditis in hospitalized patients with laboratory-confirmed influenza virus infection. Prospective studies, retrospective cohort studies, and randomized controlled trials (RCTs) were included in the analysis. We followed the PRISMA checklist and used 95% confidence intervals (CIs) to report meta-analysis outcomes. This study was registered on PROSPERO (CRD42023427849). After retrieving 2803 studies, we identified 19 studies (18 observational and 1 RCT) with relevant data, and we included 6936 patients in our analysis, of whom 690 (9.9%) developed a cardiovascular outcome of interest. The cumulative incidence of HF was 17.47% (95% CI: 5.06%-34.54%), arrhythmia of any kind 6.12% (95% CI: 0.00%-21.92%), myocarditis 2.56% (95% CI: 0.66%-5.38%), AMI 2.19% (95% CI: 1.03%-3.72%), and stroke or TIA 1.14% (95% CI: 0.00%-4.05%). The in-hospital mortality rate from cardiovascular events was 1.38% (95% CI: 0.00%-4.80%). Cardiovascular complications occur in patients with influenza virus infection, with the cumulative incidence of specific cardiac manifestations varying considerably (1.51%-17.47%). Preventive strategies and close clinical monitoring after infection remain a priority.

Estimated health and economic impact of using high-dose influenza vaccine on respiratory and circulatory plus respiratory hospitalizations of older adults in Australia

Background

Standard dose influenza vaccine provides moderate protection from infection, but with lower effectiveness among the elderly. High dose and adjuvanted vaccines (HD-TIV and aTIV) were developed to address this. This study aims to estimate the incremental health and economic impact of using HD-TIV (high dose trivalent vaccine) instead of aTIV (adjuvanted trivalent vaccine) on respiratory and circulatory plus respiratory hospitalizations of older people (≥65 years) in Australia.

Methods

This is a modelling study comparing predicted hospitalization outcomes in people receiving HD-TIV or aTIV during an average influenza season in Australia. Hospitalization records of Australian adults ≥65 years of age from 01 April to 30 November during 15 influenza seasons (2002-2017 excluding 2009, which was a pandemic) were extracted from the Australian Institute of Health and Welfare [AIHW] and used to calculate hospitalisation rates during an average season. Relative vaccine effectiveness data for aTIV and HD-TIV were used to estimate morbidity burden related to influenza.

Results

Between 2002 and 2017, the average respiratory hospitalization rate among older people during influenza season (April-November) was 3,445/100,000 population-seasons, with an average cost of AU$ 7,175 per admission. The average circulatory plus respiratory hospitalization rate among older Australian people during that time was 10,393/100,000 population-seasons, with an average cost of AU$ 7829 per admission. For older Australians, HD-TIV may avert an additional 6,315-9,410 respiratory admissions each year, with an incremental healthcare cost saving of AU$ 15.9-38.2 million per year compared to aTIV. Similar results were also noted for circulatory plus respiratory hospitalizations.

Conclusions

From the modelled estimations, HD-TIV was associated with less economic burden and fewer respiratory, and circulatory plus respiratory hospitalizations than aTIV for older Australians.

The role of vaccination in COPD: influenza, SARS-CoV-2, pneumococcus, pertussis, RSV and varicella zoster virus

Exacerbations of COPD are associated with worsening of the airflow obstruction, hospitalisation, reduced quality of life, disease progression and death. At least 70% of COPD exacerbations are infectious in origin, with respiratory viruses identified in approximately 30% of cases. Despite long-standing recommendations to vaccinate patients with COPD, vaccination rates remain suboptimal in this population.Streptococcus pneumoniae is one of the leading morbidity and mortality causes of lower respiratory tract infections. The Food and Drug Administration recently approved pneumococcal conjugate vaccines that showed strong immunogenicity against all 20 included serotypes. Influenza is the second most common virus linked to severe acute exacerbations of COPD. The variable vaccine efficacy across virus subtypes and the impaired immune response are significant drawbacks in the influenza vaccination strategy. High-dose and adjuvant vaccines are new approaches to tackle these problems. Respiratory syncytial virus is another virus known to cause acute exacerbations of COPD. The vaccine candidate RSVPreF3 is the first authorised for the prevention of RSV in adults ≥60 years and might help to reduce acute exacerbations of COPD. The 2023 Global Initiative for Chronic Lung Disease report recommends zoster vaccination to protect against shingles for people with COPD over 50 years.

The spatial distribution of interleukin-4 (IL-4) reference values in China based on a back propagation (BP) neural network

This study aimed to investigate the geospatial distribution of normal reference values of Interleukin 4 (IL-4) in healthy Chinese adults and to provide a basis for the development of standard references. IL-4 values of 5,221 healthy adults from 64 cities in China were collected and analyzed for a potential correlation with 24 topographical, climatic and soil factors. Seven of these factors were extracted and used to build a back propagation (BP) neural network model that was used to predict IL-4 reference values in healthy individuals from 2,317 observation sites nationwide. The predicted values were tested for normality and geographic distribution by analytic Kriging interpolation to map the geographic distribution of IL-4 reference values in healthy Chinese subjects. The results showed that IL-4 values generally decreased and then increased from the South to the North. We concluded that the BP neural network model applies to this approach, where certain geographical factors determine levels of various biochemical and immunological standards in healthy adults in regions with different topography, climate and soil indices.

Temporal Association Among Influenza-Like Illness, Cardiovascular Events, and Vaccine Dose in Patients With High-Risk Cardiovascular Disease: Secondary Analysis of a Randomized Clinical Trial

Importance

Influenza-like illness (ILI) activity has been associated with increased risk of cardiopulmonary (CP) events during the influenza season. High-dose trivalent influenza vaccine was not superior to standard-dose quadrivalent vaccine for reducing these events in patients with high-risk cardiovascular (CV) disease in the Influenza Vaccine to Effectively Stop Cardio Thoracic Events and Decompensated Heart Failure (INVESTED) trial.

Objective

To evaluate whether high-dose trivalent influenza vaccination is associated with benefit over standard-dose quadrivalent vaccination in reducing CP events during periods of high, local influenza activity.

Design, Setting, and Participants

This study was a prespecified secondary analysis of INVESTED, a multicenter, double-blind, active comparator randomized clinical trial conducted over 3 consecutive influenza seasons from September 2016 to July 2019. Follow-up was completed in July 2019, and data were analyzed from September 21, 2016, to July 31, 2019. Weekly Centers for Disease Control and Prevention (CDC)-reported, state-level ILI activity was ascertained to assess the weekly odds of the primary outcome. The study population included 3094 patients with high-risk CV disease from participating centers in the US.

Intervention

Participants were randomized to high-dose trivalent or standard-dose quadrivalent influenza vaccine and revaccinated for up to 3 seasons.

Main Outcomes and Measures

The primary outcome was the time to composite of all-cause death or CP hospitalization within each season. Additional measures included weekly CDC-reported ILI activity data by state.

Results

Among 3094 participants (mean [SD] age, 65 [12] years; 2309 male [75%]), we analyzed 129 285 person-weeks of enrollment, including 1396 composite primary outcome events (1278 CP hospitalization, 118 deaths). A 1% ILI increase in the prior week was associated with an increased risk in the primary outcome (odds ratio [OR], 1.14; 95% CI, 1.07-1.21; P < .001), CP hospitalization (OR, 1.13; 95% CI, 1.06-1.21; P < .001), and CV hospitalization (OR, 1.12; 95% CI, 1.04-1.19; P = .001), after adjusting for state, demographic characteristics, enrollment strata, and CV risk factors. Increased ILI activity was not associated with all-cause death (OR, 1.00; 95% CI, 0.88-1.13; P > .99). High-dose compared with standard-dose vaccine did not significantly reduce the primary outcome, even when the analysis was restricted to weeks of high ILI activity (OR, 0.88; 95% CI, 0.65-1.20; P = .43). Traditionally warmer months in the US were associated with lower CV risk independent of local ILI activity.

Conclusions and Relevance

In this secondary analysis of a randomized clinical trial, ILI activity was temporally associated with increased CP events in patients with high-risk CV disease, and a higher influenza vaccine dose did not significantly reduce temporal CV risk. Other seasonal factors may play a role in the coincident high rates of ILI and CV events.

Trial Registration

ClinicalTrials.gov Identifier: NCT02787044.

Excess mortality among people with communicable diseases over a 30-year period, Victoria, Australia: a whole of population cohort study

Background

Understanding mortality burden associated with communicable diseases is key to informing resource allocation, disease prevention and control efforts, and evaluating public health interventions. We quantified excess mortality among people notified with communicable diseases in Victoria, Australia.

Methods

Cases of communicable disease notified in Victoria between 1 January 1991 and 31 December 2021 were linked to the death registry. Informational gain obtained through linkage and 30-day case fatality rates were calculated for each disease. Standardised mortality ratios (SMR) and 95% confidence intervals were calculated up to a year following illness onset.

Findings

There were 1,032,619 cases and 5985 (0.58%) died ≤30 days of illness onset. Following linkage, the 30-day case fatality rate increased more than 2-fold. Diseases with high 7-day SMR signifying excess mortality included invasive pneumococcal disease (167.7, 95% CI 153.4-182.7); listeriosis (166.2, 95% CI 121.2-218.3); invasive meningococcal disease (145.9, 95% CI 116.7-178.3); legionellosis (43.3, 95% CI 28.0-62.0); and COVID-19 (21.9, 95% CI 19.7-24.3). Most diseases exhibited a strong negative gradient, with high SMRs in the first 7-days of illness onset that reduced over time.

Interpretation

We demonstrated that the rate of death in Victoria's notifiable disease surveillance dataset is underestimated. Further, compared to a general population, there is evidence of elevated all-cause mortality among people notified with communicable diseases often up to one year following illness onset. Not all elevated risk is likely directly attributable to the communicable diseases of interest, rather, it may reflect underlying comorbidities or behaviours in these individuals. Regardless of attribution, infection with communicable diseases may represent a marker of mortality. Key to preventing deaths may be through timely and appropriate transition to primary and preventive healthcare following diagnosis.

Funding

No funding was provided for this study.

Generation of antigen-specific memory CD4 T cells by heterologous immunization enhances the magnitude of the germinal center response upon influenza infection

Current influenza vaccine strategies have yet to overcome significant obstacles, including rapid antigenic drift of seasonal influenza viruses, in generating efficacious long-term humoral immunity. Due to the necessity of germinal center formation in generating long-lived high affinity antibodies, the germinal center has increasingly become a target for the development of novel or improvement of less-efficacious vaccines. However, there remains a major gap in current influenza research to effectively target T follicular helper cells during vaccination to alter the germinal center reaction. In this study, we used a heterologous infection or immunization priming strategy to seed an antigen-specific memory CD4+ T cell pool prior to influenza infection in mice to evaluate the effect of recalled memory T follicular helper cells in increased help to influenza-specific primary B cells and enhanced generation of neutralizing antibodies. We found that heterologous priming with intranasal infection with acute lymphocytic choriomeningitis virus (LCMV) or intramuscular immunization with adjuvanted recombinant LCMV glycoprotein induced increased antigen-specific effector CD4+ T and B cellular responses following infection with a recombinant influenza strain that expresses LCMV glycoprotein. Heterologously primed mice had increased expansion of secondary Th1 and Tfh cell subsets, including increased CD4+ TRM cells in the lung. However, the early enhancement of the germinal center cellular response following influenza infection did not impact influenza-specific antibody generation or B cell repertoires compared to primary influenza infection. Overall, our study suggests that while heterologous infection/immunization priming of CD4+ T cells is able to enhance the early germinal center reaction, further studies to understand how to target the germinal center and CD4+ T cells specifically to increase long-lived antiviral humoral immunity are needed.

Role of Endothelium in Cardiovascular Sequelae of Long COVID

The global action against coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 infection, shed light on endothelial dysfunction. Although SARS-CoV-2 primarily affects the pulmonary system, multiple studies have documented pan-vascular involvement in COVID-19. The virus is able to penetrate the endothelial barrier, damaging it directly or indirectly and causing endotheliitis and multi-organ injury. Several mechanisms cooperate to development of endothelial dysfunction, including endothelial cell injury and pyroptosis, hyperinflammation and cytokine storm syndrome, oxidative stress and reduced nitric oxide bioavailability, glycocalyx disruption, hypercoagulability, and thrombosis. After acute-phase infection, some patients reported signs and symptoms of a systemic disorder known as long COVID, in which a broad range of cardiovascular (CV) disorders emerged. To date, the exact pathophysiology of long COVID remains unclear: in addition to the persistence of acute-phase infection mechanisms, specific pathways of CV damage have been postulated, such as persistent viral reservoirs in the heart or an autoimmune response to cardiac antigens through molecular mimicry. The aim of this review is to provide an overview of the main molecular patterns of enduring endothelial activation following SARS-CoV-2 infection and to offer the latest summary of CV complications in long COVID.

Seasonal influenza vaccine uptake among patients with cardiovascular disease in Denmark, 2017-2019

BACKGROUND

Influenza vaccination protects against morbidity and mortality in patients with cardiovascular disease (CVD). We aimed to describe influenza vaccine uptake in patients with CVD in a universal-access healthcare system.

METHODS

Using nationwide Danish registries, we included all patients with prevalent CVD, defined as heart failure (HF), atrial fibrillation (AF), ischemic heart disease (IHD), or stroke during three consecutive influenza seasons (October-December 2017-2019). The outcome was relative frequency of influenza vaccination across strata of patient characteristics.

RESULTS

There was an average of 397 346 patients with CVD yearly during 2017-2019. Vaccine uptake was 45.6% for the whole population and ranged from 55.0% in AF to 61.8% in HF among patients aged ≥65 years. Among patients aged <65 years, uptake was 32.6% in HF, 19.0% in AF, 21.1% in IHD, and 18.3% in stroke. There was a lower uptake with decreasing age: 21.6% in HF, 5.5% in AF, 7.4% in IHD, and 6.3% in stroke among males aged <45 years, as opposed to 25.5% in HF, 11.5% in AF, 13.8% in IHD, and 12.1% in stroke for males aged 45-54 years. In the further stratified analyses, uptake ranged from a low of 2.5% for males <45 years with AF who were not vaccinated the previous season to a high of 87.0% for females ≥75 years with IHD who were vaccinated the previous season.

CONCLUSION

Seasonal influenza vaccine uptake is suboptimal among patients with CVD, even in a universal-access healthcare system with free-of-charge vaccinations. Vaccine uptake was particularly low among young patients.

Relative Effectiveness of the Cell-Based Quadrivalent Influenza Vaccine in Preventing Cardiorespiratory Hospitalizations in Adults Aged 18-64 Years During the 2019-2020 US Influenza Season

Background

The mammalian cell-based quadrivalent inactivated influenza vaccine (IIV4c) has advantages over egg-based quadrivalent inactivated influenza vaccine (IIV4e), as production using cell-derived candidate viruses eliminates the opportunity for egg adaptation. This study estimated the relative vaccine effectiveness (rVE) of IIV4c versus IIV4e in preventing cardiorespiratory hospitalizations during the 2019-2020 US influenza season.

Methods

We conducted a retrospective cohort study using electronic medical records linked to claims data of US individuals aged 18-64 years. We assessed rVE against cardiorespiratory hospitalizations and against subcategories of this outcome, including influenza, pneumonia, myocardial infarction and ischemic stroke, and respiratory hospitalizations. We used a doubly robust inverse probability of treatment weighting and logistic regression model to obtain odds ratios (ORs; odds of outcome among IIV4c recipients/odds of outcome among IIV4e recipients) adjusted for age, sex, race, ethnicity, geographic region, vaccination week, health status, frailty, and healthcare resource utilization. rVE was calculated as 100(1 - OR_adjusted).

Results

In total, 1 491 097 individuals (25.2%) received IIV4c, and 4 414 758 (74.8%) received IIV4e. IIV4c was associated with lower odds of cardiorespiratory (rVE, 2.5% [95% confidence interval, 0.9%-4.1%]), respiratory (3.7% [1.5%-5.8%]), and influenza (9.3% [0.4%-17.3%]) hospitalizations among adults 18-64 years of age. No difference was observed for the other outcomes.

Conclusions

This real-world study conducted for the 2019-2020 season demonstrated that vaccination with IIV4c was associated with fewer cardiorespiratory, respiratory, and influenza hospitalizations compared with IIV4e.

Influenza vaccination in mitigating vascular events and risk

PURPOSE OF REVIEW

Influenza imparts a significant health burden on the United States and global population. Furthermore, influenza is associated with acute cardiovascular events, including heart failure exacerbations, acute coronary syndromes, strokes, and overall cardiovascular mortality. We review the role of seasonal influenza vaccination in mitigating cardiovascular risk.

RECENT FINDINGS

A large study assessed the impact of influenza vaccine on cardiovascular outcomes and mortality using the US National Inpatient Sample (NIS) database. This study included 22 634 643 hospitalizations. Vaccination against influenza was associated with a reduction in myocardial infarctions (MI) [relative risk (RR) = 0.84, 95% CI 0.82-0.87, P  < 0.001], transient ischemic attacks (RR = 0.93, 95% CI 0.9-0.96, P  < 0.001), cardiac arrests (RR = 0.36, 95% CI 0.33-0.39, P  < 0.001), strokes (RR = 0.94, 95% CI 0.91-0.97, P  < 0.001), and overall mortality (RR = 0.38, 95% CI 0.36-0.4, P  < 0.001).

SUMMARY

Available data suggests that seasonal influenza vaccination is very effective in mitigating cardiovascular risk. Increasing the rates of influenza vaccination, especially among those with cardiovascular risk factors, is critical in preventing infection and attenuating influenza-related cardiovascular complications and adverse outcomes.

Influenza A(H1N1)pdm09 Virus Aggravates Pathology of Blood Vessels in Wistar Rats with Premorbid Acute Cardiomyopathy

Influenza virus can infect the vascular endothelium and cause endothelial dysfunction. Persons at higher risk for severe influenza are patients with acute and chronic cardiovascular disorders; however, the mechanism of influenza-induced cardiovascular system alteration remains not fully understood. The aim of the study was to assess the functional activity of mesenteric blood vessels of Wistar rats with premorbid acute cardiomyopathy infected with Influenza A(H1N1)pdm09 virus. For this, we determined (1) the vasomotor activity of mesenteric blood vessels of Wistar rats using wire myography, (2) the level of expression of three endothelial factors: endothelial nitric oxide synthase (eNOS), plasminogen activator inhibitor-1 (PAI-1), and tissue plasminogen activator (tPA) in the endothelium of mesenteric blood vessels using immunohistochemistry, and (3) the concentration of PAI-1 and tPA in the blood plasma using ELISA. Acute cardiomyopathy in animals was induced by doxorubicin (DOX) following infection with rat-adapted Influenza A(H1N1)pdm09 virus. The functional activity of mesenteric blood vessels was analyzed at 24 and 96 h post infection (hpi). Thus, the maximal response of mesenteric arteries to both vasoconstrictor and vasodilator at 24 and 96 hpi was significantly decreased compared with control. Expression of eNOS in the mesenteric vascular endothelium was modulated at 24 and 96 hpi. PAI-1 expression increased 3.47-fold at 96 hpi, while the concentration of PAI-1 in the blood plasma increased 6.43-fold at 24 hpi compared with control. The tPA concentration in plasma was also modulated at 24 hpi and 96 hpi. The obtained data indicate that influenza A(H1N1)pdm09 virus aggravates the course of premorbid acute cardiomyopathy in Wistar rats, causing pronounced dysregulation of endothelial factor expression and vasomotor activity impairment of mesenteric arteries.

Cardiovascular Complications Are the Primary Drivers of Mortality in Hospitalized Patients With SARS-CoV-2 Community-Acquired Pneumonia

BACKGROUND

Hospitalized patients with SARS-CoV-2 community-acquired pneumonia (CAP) and associated comorbidities are at increased risk of cardiovascular complications. The magnitude of effect of cardiovascular complications and the role of prior comorbidities on clinical outcomes are not well defined.

RESEARCH QUESTION

What is the impact of cardiovascular complications on mortality in hospitalized patients with SARS-CoV-2 CAP? What is the impact of comorbidities and other risk factors on the risk of developing cardiovascular complications and mortality in these patients?

STUDY DESIGN AND METHODS

This cohort study included 1,645 hospitalized patients with SARS-CoV-2 CAP. Cardiovascular complications were evaluated. The clinical course during hospitalization was described by using a multistate model with four states: (1) hospitalized with no cardiovascular complications; (2) hospitalized with cardiovascular complications; (3) discharged alive; (4) and dead. Cox proportional hazards regression was used to analyze the impact of prior comorbid conditions on transitions between these states. Hazard ratios (HRs) and 95% CIs are reported.

RESULTS

Cardiovascular complications occurred in 18% of patients hospitalized with SARS-CoV-2 CAP. The mortality rate in this group was 45% vs 13% in patients without cardiovascular complications. Male subjects (HR, 1.32; 95% CI, 1.03-1.68), older adults (HR, 1.34; 95% CI, 1.03-1.75), and patients with congestive heart failure (HR, 1.59; 95% CI, 1.18-2.15), coronary artery disease (HR, 1.34; 95% CI, 1.00-1.79), atrial fibrillation (HR, 1.43; 95% CI, 1.06-1.95), direct admissions to the ICU (HR, 1.77; 95% CI, 1.36-2.32), and Pao2/Fio2 < 200 (HR, 1.46; 95% CI, 1.11-1.92) were more likely to develop cardiovascular complications following hospitalization for SARS-CoV-2 CAP; however, these factors are not associated with increased risk of death following a cardiovascular complication.

INTERPRETATION

Prior comorbidities, older age, male sex, severity of illness, and hypoxemia are associated with increased risk of cardiovascular complications. Once patients develop cardiovascular complications, the risk of death is extremely high. Cardiovascular complications are the primary drivers of mortality in hospitalized patients with SARS-CoV-2 CAP.

Nationwide Analysis of Cardiac Arrest Outcomes During the COVID-19 Pandemic

Introduction

The coronavirus disease 2019 (COVID-19) pandemic had a significant impact on the chain of survival following cardiac arrest. However, large population-based reports of COVID-19 in patients hospitalized after cardiac arrest are limited.

Methods

The National Inpatient Sample database was queried for cardiac arrest admissions during 2020 in the United States (US). Propensity score matching was used to match patients with and without concurrent COVID-19 according to age, race, sex, and comorbidities. Multivariate logistic regression analysis was used to identify predictors of mortality.

Results

A weighted total of 267,845 hospitalizations for cardiac arrest were identified, among which 44,105 patients (16.5%) had a concomitant diagnosis of COVID-19. After propensity matching, cardiac arrest patients with concomitant COVID-19 had higher rate of acute kidney injury requiring dialysis (64.9% vs. 54.8%) mechanical ventilation > 24 hours (53.6% vs. 44.6%) and sepsis (59.4% vs. 40.4%) compared to cardiac arrest patients without COVID-19. In contrast, cardiac arrest patients with COVID-19 had lower rates of cardiogenic shock (3.2% vs. 5.4%, p < 0.001), ventricular tachycardia (9.6% vs. 11.7%, p < 0.001), and ventricular fibrillation (6.7% vs. 10.8%, p < 0.001), and a lower utilization of cardiac procedures. In-hospital mortality was higher in patients with COVID-19 (86.9% vs. 65.5%, p <0.001) and, on multivariate analysis, a diagnosis of COVID-19 was an independent predictor of mortality.

Conclusion

Among patients hospitalized following a cardiac arrest during 2020, concomitant COVID-19 infection was associated with significantly worse outcomes characterized by an increased risk of sepsis, pulmonary and renal dysfunction, and death.

Associations between mortality from COVID-19 and other causes: A state-level analysis

BACKGROUND

During the COVID-19 pandemic, the high death toll from COVID-19 was accompanied by a rise in mortality from other causes of death. The objective of this study was to identify the relationship between mortality from COVID-19 and changes in mortality from specific causes of death by exploiting spatial variation in these relationships across US states.

METHODS

We use cause-specific mortality data from CDC Wonder and population estimates from the US Census Bureau to examine relationships at the state level between mortality from COVID-19 and changes in mortality from other causes of death. We calculate age-standardized death rates (ASDR) for three age groups, nine underlying causes of death, and all 50 states and the District of Columbia between the first full year of the pandemic (March 2020-February 2021) and the year prior (March 2019-February 2020). We then estimate the relationship between changes in cause-specific ASDR and COVID-19 ASDR using linear regression analysis weighted by the size of the state's population.

RESULTS

We estimate that causes of death other than COVID-19 represent 19.6% of the total mortality burden associated with COVID-19 during the first year of the COVID-19 pandemic. At ages 25+, circulatory disease accounted for 51.3% of this burden while dementia (16.4%), other respiratory diseases (12.4%), influenza/pneumonia (8.7%) and diabetes (8.6%) also contribute. In contrast, there was an inverse association across states between COVID-19 death rates and changes in death rates from cancer. We found no state-level association between COVID-19 mortality and rising mortality from external causes.

CONCLUSIONS

States with unusually high death rates from COVID-19 experienced an even larger mortality burden than implied by those rates alone. Circulatory disease served as the most important route through which COVID-19 mortality affected death rates from other causes of death. Dementia and other respiratory diseases made the second and third largest contributions. In contrast, mortality from neoplasms tended to decline in states with the highest death rates from COVID-19. Such information may help to inform state-level responses aimed at easing the full mortality burden of the COVID-19 pandemic.

Retrospective analyses of the outcomes among hospitalized liver cirrhosis patients with heart failure and COVID-19 infection: Insight from the National Inpatient Sample

Background

There is paucity of data regarding the impact of Coronavirus Disease 2019 (COVID-19) infection on the outcomes of hospitalized liver cirrhosis (LC) patients with heart failure (HF).

Methods

Utilizing the 2020 National Inpatient Sample (NIS) Database, we conducted a retrospective cohort study to investigate the outcomes of hospitalized LC patients with HF and COVID-19 infection, looking at its impact on in-hospital mortality, risk for acute kidney injury (AKI) and length of stay (LOS).

Results

We identified a total of 10,810 hospitalized LC patients with HF, of which 1.39 % (n = 150/10,810) had COVID-19 infection. Using a stepwise survey multivariable logistic regression model that adjusted for patient and hospital level confounders, COVID-19 infection among hospitalized LC patients with HF was found to be an independent predictor of overall in-hospital mortality (aOR 3.73; 95 % CI, 1.58-8.79; p = 0.00) and risk for AKI (aOR 3.06; 95 % CI, 1.27-7.37; p = 0.01) compared to those without COVID-19 infection. However, there were comparable rates of LOS among LC patients with HF regardless of COVID-19 infection status. Moreover, AKI was found to be an independent predictor of longer LOS (coefficient 4.40, 95 % CI 3.26-5.38; p = 0.00). On subgroup analysis, diastolic HF was found to be associated with increased risk for in-hospital mortality (aOR 6.54; 95 % CI, 2.02-21.20; p = 0.00), development of AKI (aOR 3.33; 95 % CI, 1.12-9.91; p = 0.03) and longer LOS (coefficient 4.30, 95 % CI 0.79-9.45; p = 0.03).

Conclusion

Concomitant COVID-19 infection among hospitalized LC patients with HF was associated with higher risk for in-hospital mortality and AKI but did not significantly affect hospital LOS.

Seasonality of head and neck cancers

PURPOSE

The purpose of this study is to investigate if the season of diagnosis is associated with patient, tumor, and treatment characteristics within head and neck cancer.

MATERIALS AND METHODS

1406 patients with a diagnosis of head and neck cancer (HNC) were identified from a HNC database (1996-2019). Patients were classified as receiving a diagnosis in the winter, spring, summer, or fall by calendar definition. Proportions and chi-squared analysis compared patient, tumor, and treatment factors for all diagnoses. Data was subdivided and analyzed based on the primary site.

RESULTS

From this cohort, 23 %, 27 %, 25 %, and 25 % of HNC patients were diagnosed in winter, spring, summer, and fall respectively with no statistically significant difference between seasons of diagnosis. When subdivided by primary site, oral cavity cancer was significantly more likely to be diagnosed in spring, salivary gland cancer was more likely to be diagnosed in winter and summer (p = 0.03 and p = 0.01 respectively). No other demographic, clinicopathologic, or management characteristics were associated with the season of diagnosis (p > 0.05 for all).

CONCLUSIONS

Diagnosis of head and neck cancer does not follow a seasonal pattern. Diagnosis of oral cavity and salivary gland cancer showed a seasonal pattern. The majority of patient, tumor and management characteristics were not associated with the.

Impact of General Practitioner Education on Acceptance of an Adjuvanted Seasonal Influenza Vaccine among Older Adults in England

Seasonal vaccination against influenza and in-pandemic COVID-19 vaccination are top public health priorities; vaccines are the primary means of reducing infections and also controlling pressures on health systems. During the 2018-2019 influenza season, we conducted a study of the knowledge, attitudes, and behaviours of 159 general practitioners (GPs) and 189 patients aged ≥65 years in England using a combination of qualitative and quantitative approaches to document beliefs about seasonal influenza and seasonal influenza vaccine. GPs were surveyed before and after a continuing medical education (CME) module on influenza disease and vaccination with an adjuvanted trivalent influenza vaccine (aTIV) designed for patients aged ≥65 years, and patients were surveyed before and after a routine visit with a GP who participated in the CME portion of the study. The CME course was associated with significantly increased GP confidence in their ability to address patients' questions and concerns about influenza disease and vaccination (p < 0.001). Patients reported significantly increased confidence in the effectiveness and safety of aTIV after meeting their GP. Overall, 82.2% of the study population were vaccinated against influenza (including 137 patients vaccinated during the GP visit and 15 patients who had been previously vaccinated), a rate higher than the English national average vaccine uptake of 72.0% that season. These findings support the value of GP-patient interactions to foster vaccine acceptance.

Outcomes among ST-Elevation Myocardial Infarction (STEMI) patients with cardiogenic shock and COVID-19: A nationwide analysis

Background

There is paucity of data regarding the characteristics and outcomes of patients admitted for ST Elevation Myocardial Infarction (STEMI) complicated by cardiogenic shock (CS) with concomitant Coronavirus Disease 2019 (COVID-19) infection.

Methods

Using the National Inpatient Sample (NIS) Database for the year 2020, we conducted a retrospective cohort study to investigate the outcomes of patients who sustained STEMI-associated cardiogenic shock (STEMI-CS) with concomitant COVID-19 infection looking at its impact on in-hospital mortality and secondarily at the in-hospital procedure and intervention utilization rates as well as hospital length of stay.

Results

We identified a total of 22,775 patients with STEMI-CS, of which 1.71 % (n = 390/22,775) had COVID-19 infection. Using a stepwise survey multivariable logistic regression model that adjusted for patient and hospital level confounders, concomitant COVID-19 infection among STEMI-CS patients was found to be an independent predictor of overall in-hospital mortality compared to those without COVID-19 (adjusted OR 2.10; 95 % confidence interval [CI], 1.30-3.40). STEMI-CS patients with concomitant COVID-19 infection had similar in-hospital utilization rates for percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG), extracorporeal membrane oxygenation (ECMO), percutaneous and durable left ventricular device, intra-arterial aortic balloon pump (IABP), renal replacement therapy (RRT), mechanical ventilation, as well as similar hospital lengths of stay.

Conclusion

Concomitant COVID-19 infection was associated with higher in-hospital mortality rates among patients with cardiogenic shock related to STEMI but had similar in-hospital procedure and intervention utilization rates as well as hospital length of stay.

Maintaining a 'fit' immune system: the role of vaccines

INTRODUCTION

Conventionally, vaccines are thought to induce a specific immune response directed against a target pathogen. Long recognized but poorly understood nonspecific benefits of vaccination, such as reduced susceptibility to unrelated diseases or cancer, are now being investigated and may be due in part to "trained immunity'.

AREAS COVERED

We discuss 'trained immunity' and whether vaccine-induced 'trained immunity' could be leveraged to prevent morbidity due to a broader range of causes.

EXPERT OPINION

The prevention of infection i.e. maintaining homeostasis by preventing the primary infection and resulting secondary illnesses, is the pivotal strategy used to direct vaccine design and may have long-term, positive impacts on health at all ages. In the future, we anticipate that vaccine design will change to not only prevent the target infection (or related infections) but to generate positive modifications to the immune response that could prevent a wider range of infections and potentially reduce the impact of immunological changes associated with aging. Despite changing demographics, adult vaccination has not always been prioritized. However, the SARS-CoV-2 pandemic has demonstrated that adult vaccination can flourish given the right circumstances, demonstrating that harnessing the potential benefits of life-course vaccination is achievable for all.

Global, regional and national estimates of influenza-attributable ischemic heart disease mortality

BACKGROUND

Influenza virus infection is associated with incident ischemic heart disease (IHD) events. Here, we estimate the global, regional, and national IHD mortality burden attributable to influenza.

METHODS

We used vital registration data from deaths in adults ≥50 years (13.2 million IHD deaths as underlying cause) to assess the relationship between influenza activity and IHD mortality in a non-linear meta-regression framework from 2010 to 2019. This derived relationship was then used to estimate the global influenza attributable IHD mortality. We estimated the population attributable fraction (PAF) of influenza for IHD deaths based on the relative risk associated with a given level of weekly influenza test positivity rate and multiplied PAFs by IHD mortality from the Global Burden of Disease study.

FINDINGS

Influenza activity was associated with increased risk of IHD mortality across all countries analyzed. The mean PAF of influenza for IHD mortality was 3.9% (95% uncertainty interval [UI] 2.5-5.3%), ranging from <1% to 10%, depending on country and year. Globally, 299,858 IHD deaths (95% UI 191,216-406,809) in adults ≥50 years could be attributed to influenza, with the highest rates per 100,000 population in the Central Europe, Eastern Europe and Central Asia Region (32.3; 95% UI 20.6-43.8), and in the North Africa and Middle East Region (26.7; 95% UI 17-36.2).

INTERPRETATION

Influenza may contribute substantially to the burden of IHD. Our results suggest that if there were no influenza, an average of 4% of IHD deaths globally would not occur.

FUNDING

Collaborative study funded by Sanofi Vaccines.

Elucidation of the inhibitory activity of plant-derived SARS-CoV inhibitors and their potential as SARS-CoV-2 inhibitors

Several drugs are now being tested as possible therapies due to the necessity of treating SARS-CoV-2 infection. Although approved vaccines bring much hope, a vaccination program covering the entire global population will take a very long time, making the development of effective antiviral drugs an effective solution for the immediate treatment of this dangerous infection. Previous studies found that three natural compounds, namely, tannic acid, 3-isotheaflavin-3-gallate and theaflavin-3,3-digallate, are effective proteinase (3CL^pro) inhibitors of SARS-CoV (IC₅₀ <10 µM). Based on this information and due to the high sequence identity between SARS-CoV and SARS-CoV-2 3CL^pro, these three compounds could be candidate inhibitors of SARS-CoV-2 3CL^pro. This paper explores the structural and energetic features that guided the molecular recognition of these three compounds for dimeric SARS-CoV-2 and SARS-CoV 3CL^pro, the functional state of this enzyme, using docking and MD simulations with the molecular mechanics-generalized-born surface area (MMGBSA) approach. Energetic analysis demonstrated that the three compounds reached good affinities in both systems in the following order: tannic acid > 3-isotheaflavin-3-gallate > theaflavin-3,3-digallate. This tendency is in line with that experimentally reported between these ligands and SARS-CoV 3CL^pro. Therefore, tannic acid may have clinical usefulness against COVID-19 by acting as a potent inhibitor of SARS-CoV-2 3CL^pro.Communicated by Ramaswamy H. Sarma.

The association between health information technology and influenza vaccine uptake among adults with heart disease

Aim: Assess the association of health information technology (HIT) on influenza vaccine (IV) uptake among adults with heart disease. Methods: The association of four different uses of HIT - (1) look up health information, (2) schedule medical appointments, (3) refill prescriptions online and (4) communicate with healthcare providers on IV uptake - was analyzed using multiple logistic regression. Results: Adults with heart disease who use the internet to look up information (adjusted odds ratio [AOR] = 1.48, 95% CI: 1.39-1.59; p < 0.001), fill up prescription (AOR = 1.87, 95% CI: 1.69-2.06; p < 0.001), and communicate with a healthcare provider (AOR = 1.95, 95% CI: 1.23-3.10; p = 0.005) had a higher uptake of IV unlike those who did not. Conclusion: Using the internet in patient-healthcare system engagement via HIT was associated with increase IV uptake. Future studies should assess the impact of population-level variables on this relationship.

How the COVID 19 pandemic will shape influenza public health initiatives: The UK experience

Although caused by different pathogens, COVID-19 and influenza share many clinical features, as well as the potential for inflammatory, cardiovascular, and other long-term complications. During the 2020-2021 influenza season, COVID-19 mitigation efforts and a robust influenza vaccination campaign led to an unprecedented reduction in influenza cases. The lack of exposure to influenza, along with antigenic changes, may have reduced population immunity to influenza and set the stage for a high severity influenza season in 2021-2022. For the second consecutive season, the UK Department of Health and Social Care has expanded influenza vaccine eligibility to mitigate the impact of both COVID-19 and influenza. Continuation of clear policy decisions, as well as ongoing coordination between manufacturers, distributors, health authorities, and healthcare providers, is key to reducing the burden of influenza and COVID-19 and preventing large numbers of severe cases that can overwhelm the healthcare system.

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

Elucidation of the inhibitory activity of ivermectin with host nuclear importin α and several SARS-CoV-2 targets

Ivermectin (IVM) is an FDA-approved drug that has shown antiviral activity against a wide variety of viruses in recent years. IVM inhibits the formation of the importin-α/β1 heterodimeric complex responsible for the translocation and replication of various viral species proteins. Also, IVM hampers SARS-CoV-2 replication in vitro; however, the molecular mechanism through which IVM inhibits SARS-CoV-2 is not well understood. Previous studies have explored the molecular mechanism through which IVM inhibits importin-α and several potential targets associated with COVID-19 by using docking approaches and MD simulations to corroborate the docked complexes. This study explores the energetic and structural properties through which IVM inhibits importin-α and five targets associated with COVID-19 by using docking and MD simulations combined with the molecular mechanics generalized Born surface area (MMGBSA) approach. Energetic and structural analysis showed that the main protease 3CLpro reached the most favorable affinity, followed by importin-α and Nsp9, which shared a similar relationship. Therefore, in vitro activity of IVM can be explained by acting as an inhibitor of importin-α, dimeric 3CLpro, and Nsp9, but mainly over dimeric 3CLpro.Communicated by Ramaswamy H. Sarma.