Association of COVID-19 vaccination with risks of hospitalization due to cardiovascular and other diseases: A study using data from the UK Biobank

OBJECTIVES

To explore whether COVID-19 vaccination protects against hospital admission by preventing infections and severe disease.

METHODS

We leveraged the UK Biobank and studied associations of COVID-19 vaccination (BioNTech-BNT162b2 or Oxford-AstraZeneca-ChAdOx1) with hospitalizations from cardiovascular and other selected diseases (N = 393,544; median follow-up = 54 days among vaccinated individuals). Multivariable Cox, Poisson regression, propensity score matching, and inverse probability treatment weighting analyses were performed. We also performed adjustment using prescription-time distribution matching, and prior event rate ratio.

RESULTS

We observed that COVID-19 vaccination (at least one dose), compared with no vaccination, was associated with reduced short-term risks of hospitalizations from stroke (hazard ratio [HR] = 0.178, 95% confidence interval [CI]: 0.127-0.250, P = 1.50e-23), venous thromboembolism (HR = 0.426, CI: 0.270-0.673, P = 2.51e-4), dementia (HR = 0.114, CI: 0.060-0.216; P = 2.24e-11), non-COVID-19 pneumonia (HR = 0.108, CI: 0.080-0.145; P = 2.20e-49), coronary artery disease (HR = 0.563, CI: 0.416-0.762; P = 2.05e-4), chronic obstructive pulmonary disease (HR = 0.212, CI: 0.126-0.357; P = 4.92e-9), type 2 diabetes (HR = 0.216, CI: 0.096-0.486, P = 2.12e-4), heart failure (HR = 0.174, CI: 0.118-0.256, P = 1.34e-18), and renal failure (HR = 0.415, CI: 0.255-0.677, P = 4.19e-4), based on standard Cox regression models. Among the previously mentioned results, reduced hospitalizations for stroke, heart failure, non-COVID-19 pneumonia, and dementia were consistently observed across regression, propensity score matching/inverse probability treatment weighting, prescription-time distribution matching, and prior event rate ratio. The results for two-dose vaccination were similar.

CONCLUSIONS

Taken together, this study provides further support to the safety and benefits of COVID-19 vaccination, and such benefits may extend beyond reduction of infection risk or severity per se. However, causal relationship cannot be concluded and further studies are required.

New Directions in Infection-Associated Ischemic Stroke

The relationship between infections and stroke has not been fully characterized, probably delaying the development of specific treatments. This narrative review addresses mechanisms of stroke linked to infections, including hypercoagulability, endothelial dysfunction, vasculitis, and impaired thrombolysis. SARS-CoV-2, the virus that causes COVID-19, may promote the development of stroke, which may represent its most severe neurological complication. The development of specific therapies for infection-associated stroke remains a profound challenge. Perhaps the most important remaining issue is the distinction between infections that trigger a stroke versus infections that are truly incidental. This distinction likely requires the establishment of appropriate biomarkers, candidates of which are elevated levels of fibrin D-dimer and anticardiolipin/antiphospholipid antibodies. These candidate biomarkers might have potential use in identifying pathogenic infections preceding stroke, which is a precursor to establishing specific therapies for this syndrome.

Assessing interventions to encourage primary care health workers to recommend influenza vaccination and the impact on vaccination uptake for persons with Non-Communicable diseases in China

BACKGROUND

Influenza vaccination coverage is low among persons with non-communicable diseases (NCDs) in China. Chinese health workers (HWs) do not routinely recommend influenza vaccination despite evidence that recommendations increase vaccine uptake. This study aims to assess whether interventions increased primary care HWs' recommendation for influenza vaccination and measure their impact on influenza vaccine uptake in persons with NCDs.

METHODS

We conducted a cluster randomized controlled study in public primary healthcare clinics in Hubei from November 2018 through April 2019. In the intervention clinics, primary care HWs received training on the benefits of influenza vaccination and were asked to recommend influenza vaccine in routine primary healthcare for persons with NCDs. In the control clinics, primary care HWs did not receive training and provided standard services. We conducted questionnaire surveys before and after the intervention to collect information about recommendations made and receipt of influenza vaccines.

RESULTS

A total of 896 primary care HWs and 4552 persons with NCDs were included. After intervention, a higher percentage of HWs recommended influenza vaccines in intervention clinics compared to control clinics. Vaccinated primary care HWs were more likely to recommend vaccination. Persons with NCDs reported higher influenza vaccination coverage in intervention than control clinics, and primary care HWs' recommendation increased vaccination uptake among persons with NCDs.

CONCLUSIONS

Vaccinated primary care HWs were more likely to recommend influenza vaccination than unvaccinated HWs. Promoting primary care HWs' vaccination and encouraging them to recommend influenza vaccination during routine primary healthcare could increase influenza vaccine receipt among persons with NCDs. Registration number ChiCTR2200067140.

Covid-19 and influenza vaccine effectiveness against associated hospital admission and death among individuals over 65 years in Norway: A population-based cohort study, 3 October 2022 to 20 June 2023

BACKGROUND

Co-circulation of SARS-CoV-2 and influenza virus can lead to double epidemics and increased pressure on health systems. To evaluate the effect of both vaccines, we estimated the adjusted vaccine effectiveness (aVE) of influenza and Covid-19 vaccines against related severe disease in the elderly population in Norway during the 2022/2023 season.

METHODS

In this population-based cohort study, we included data from the Emergency preparedness register for Covid-19 (Beredt C19) on all individuals ≥ 65 years living in Norway between 3 October 2022 and 20 June 2023. Using Cox-proportional hazard models, we estimated aVE of both influenza and Covid-19 vaccines (bivalent BA.1 and BA.4-5) against associated hospitalisation and death. Vaccine status was included as a time-varying covariate and all models were adjusted for potential confounders, including the other vaccine.

RESULTS

We identified 2,437 influenza-associated hospitalisations and 178 deaths, alongside 5,824 Covid-19-associated hospitalisations and 621 deaths. The aVE was highest in the first three months after receiving either vaccine. Against influenza-associated hospitalisation the aVE was 34 % (26 %-42 %) among 65-79-year-olds and 40 % (30 %-48 %) among ≥ 80-year-olds, and 6.6 % (-64 %-47 %) and 37 % (0.5 %-61 %) against influenza-associated death, respectively. The aVE against Covid-19-associated hospitalisation was 65 % (61 %-69 %) among 65-79-year-olds and 55 % (49 %-60 %) among ≥ 80-year-olds (compared to having received the vaccine ≥ 180 days ago). Similarly, the aVE against Covid-19-associated death was 68 % (48 %-80 %) and 78 % (65 %-86 %), respectively. For Covid-19 we show a reduction in aVE with time since dose.

CONCLUSION

Covid-19 and influenza vaccines reduced the risk of severe disease in the same high-risk population. Ensuring high uptake of both vaccines could thus limit the overall health care burden.

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.

The Impact of Adjuvanted Influenza Vaccine on Disease Severity in the US: A Stochastic Model

Influenza can exacerbate underlying medical conditions. In this study, we modelled the potential impact of an egg-based quadrivalent influenza vaccine (QIVe) or adjuvanted QIV (aQIV) on hospitalizations and mortality from influenza-related cardiovascular disease (CVD), respiratory, and other complications in adults ≥65 years of age in the US with underlying chronic conditions. We used a stochastic decision-tree model, with 1000 simulations varying input across predicted ranges. Due to the variable nature of influenza across seasons and differences in published estimates for input parameters, data are presented as 95% confidence intervals. Compared with no vaccination, use of aQIV would prevent 135,450-564,360 hospitalizations and 1612-29,226 deaths across outcomes evaluated. Overall, aQIV prevented 1071-18,388 more hospitalizations and 85-1944 more deaths than QIVe. By routine seasonal vaccination against influenza, a substantial number of severe influenza-associated complications and deaths, caused by direct influenza symptoms or by exacerbation of chronic conditions, can be prevented in high-risk adults ≥65 years of age in the US.

Outcomes after surgery in patients with and without recent influenza: a nationwide population-based study

Background

The influence of recent influenza infection on perioperative outcomes is not completely understood.

Method

Using Taiwan's National Health Insurance Research Data from 2008 to 2013, we conducted a surgical cohort study, which included 20,544 matched patients with a recent history of influenza and 10,272 matched patients without. The main outcomes were postoperative complications and mortality. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for the complications and for mortality in patients with a history of influenza within 1-14 days or 15-30 days compared with non-influenza controls.

Results

Compared with patients who had no influenza, patients with influenza within preoperative days 1-7 had increased risks of postoperative pneumonia (OR 2.22, 95% CI 1.81-2.73), septicemia (OR 1.98, 95% CI 1.70-2.31), acute renal failure (OR 2.10, 95% CI 1.47-3.00), and urinary tract infection (OR 1.45, 95% CI 1.23-1.70). An increased risk of intensive care admission, prolonged length of stay, and higher medical expenditure was noted in patients with history of influenza within 1-14 days.

Conclusion

We found that there was an association between influenza within 14 days preoperatively and the increased risk of postoperative complications, particularly with the occurrence of influenza within 7 days prior to surgery.

A Systematic Review and Meta-Analysis of the Relationship between Receiving the Flu Vaccine with Acute Cerebrovascular Accident and Its Hospitalization in the Elderly

Background and Aims

In recent years, various studies have been conducted worldwide to investigate the relationship between receiving the flu vaccine with acute cerebrovascular accident or stroke and its hospitalization in the elderly; however, the results of these studies are contradictory. Therefore, this study was aimed at investigating the relationship between receiving the flu vaccine with stroke and its hospitalization in the elderly.

Methods

This study is a systematic review and meta-analysis of studies examining the relationship between receiving the flu vaccine with stroke and its hospitalization in the elderly during the years 1980 to 2021 which have been published in ISI Web of Science, Scopus PubMed, Cochrane, Science Direct, Google Scholar, and Embase. All analyses were performed by Stata 15, and the significance level in this study was considered <0.05.

Results

In the systematic search, 3088 articles were retrieved, considering the study criteria; finally, 14 studies were included in the meta-analysis. Based on the results of the meta-analysis, the odds ratio (OR) of occurrence and hospitalization of stroke compared to the nonvaccinated group in vaccine recipients is equal to 0.84 (95% confidence interval (CI): 0.78-0.90, P value ≤ 0.001). Publication bias was not observed in this study (P value = 0.101).

Conclusion

Getting the flu vaccine can reduce the risk of occurrence and hospitalization of stroke in the elderly by 16% (10%-22%). Therefore, receiving this vaccine as a preventive intervention for stroke in the elderly may be promising.

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

Influenza Vaccination and Risk of Ischemic Stroke: A Population-Based Case-Control Study

BACKGROUND AND OBJECTIVES

To assess the relationship between influenza vaccination in the general population and risk of a first ischemic stroke (IS) during pre-epidemic, epidemic, and postepidemic periods.

METHODS

A nested case-control study was conducted in a Spanish primary care database over 2001-2015. Individuals aged 40-99 years with at least 1 year registry and no history of stroke or cancer were selected to conform the source cohort, from which incident IS cases were identified and classified as cardioembolic or noncardioembolic. Five controls per case were randomly selected, individually matched with cases for exact age, sex, and date of stroke diagnosis (index date). A patient was considered vaccinated when he/she had a recorded influenza vaccination at least 14 days before the index date within the same season. Adjusted odds ratios (aORs) and their respective 95% CIs were computed through a conditional logistic regression. Pneumococcal vaccination was used as a negative control.

RESULTS

From a cohort of 3,757,621 patients, we selected 14,322 incident IS cases (9,542 noncardioembolic and 4,780 cardioembolic) and 71,610 matched controls. Of them, 41.4% and 40.5%, respectively, were vaccinated yielding a crude OR of 1.05 (95% CI 1.01-1.10). Vaccinated patients presented a higher prevalence of vascular risk factors, diseases, and comedication than those nonvaccinated, and after full adjustment, the association of influenza vaccination with IS yielded an aOR of 0.88 (95% CI 0.84-0.92), appearing early (aOR15-30 days 0.79; 95% CI 0.69-0.92) and slightly declining over time (aOR>150 days 0.92; 95% CI 0.87-0.98). A reduced risk of similar magnitude was observed with both types of IS, in the 3 epidemic periods, and in all subgroups analyzed (men, women, individuals younger and older than 65 years of age, and those with intermediate and high vascular risk). By contrast, pneumococcal vaccination was not associated with a reduced risk of IS (aOR 1.08; 95% CI 1.04-1.13).

DISCUSSION

Results are compatible with a moderate protective effect of influenza vaccine on IS appearing early after vaccination. The finding that a reduced risk was also observed in pre-epidemic periods suggests that either the "protection" is not totally linked to prevention of influenza infection or it may be partly explained by unmeasured confounding factors.

Association between influenza vaccination and risk of stroke in Alberta, Canada: a population-based study

BACKGROUND

Respiratory infection can be an immediate precursor to stroke and myocardial infarction. Influenza vaccination is associated with reduced risk of myocardial infarction and hospitalisation for cardiac disease, and influenza vaccination is strongly recommended for patients with heart disease. Evidence on whether the same protective association exists for stroke, and whether this potential effect is consistent across age and risk groups, is conflicting. We aimed to assess the risk of stroke after influenza vaccination in adults.

METHODS

We obtained administrative data from the Alberta Health Care Insurance Plan (which covers all residents of Alberta, Canada) beginning on Sept 30, 2009, or May 15 of the year in which residents were recorded as being 18 years of age. Individuals were censored at the earliest of three events: death, recorded outmigration, or Dec 31, 2018. The outcome of interest was any stroke event, comprising acute ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage, and transient ischaemic attack. We used Andersen-Gill Cox models to analyse the hazard of any stroke event for individuals with recent (&lt;182 days) influenza vaccination compared with those without recent influenza vaccination, with adjustment for age, sex, anticoagulant use, atrial fibrillation, chronic obstructive pulmonary disease, diabetes, hypertension, income quintile, and rural or urban home location. Two-way interaction terms between each individual covariate and vaccination status were used to assess for effect modification by risk factor. The association between vaccination and risk of each type of stroke was also modelled, adjusting for baseline covariates.

FINDINGS

The study sample consisted of 4 141 209 adults (29 687 899 person-years of observation time) registered under the provincial health-care system between Sept 30, 2009, and Dec 31, 2018. 1 769 565 (42·73%) individuals received at least one vaccination during the study period, and 38 126 stroke events were recorded. Adjusted for demographics and comorbidities, recent influenza vaccination significantly reduced the hazard of stroke (hazard ratio 0·775 [95% CI 0·757-0·793]). This association persisted across all stroke types. We found effect modification by each covariate examined except for home location; however, vaccination was associated with a reduced risk of stroke overall across all ages and risk profiles with the exception of individuals without hypertension.

INTERPRETATION

The risk of stroke is reduced among people who have recently been vaccinated against influenza compared with those who have not. This association extended to the entire adult population and was not limited to individuals with a baseline high risk of stroke. Further studies in a variety of settings are needed to evaluate whether influenza vaccination could be used as a public health strategy to prevent stroke.

FUNDING

None.

Impact of industry sponsorship on the quality of systematic reviews of vaccines: a cross-sectional analysis of studies published from 2016 to 2019

BACKGROUND

Systematic reviews (SRs) provide the highest level of evidence and inform evidence-based decision making in health care. Earlier studies found association with industry to be negatively associated with methodological quality of SRs. However, this has not been investigated in SRs on vaccines.

METHODS

We performed a systematic literature search using MEDLINE and EMBASE in March 2020. The results were restricted to those published between 2016 and 2019 with no language restrictions. Study characteristics were extracted by one person and checked by an experienced reviewer. The methodological quality of the SRs was assessed with the AMSTAR 2 tool by multiple reviewers after a calibration exercise was performed. A summary score for each SR was calculated. The Mann-Whitney U test and Fisher's exact test were performed to compare both groups.

RESULTS

Out of 185 SRs that met all inclusion criteria, 27 SRs were industry funded. Those were matched with 30 non-industry funded SRs resulting in a total sample size of 57. The mean AMSTAR 2 summary score across all SRs was 0.49. Overall, the median AMSTAR 2 summary score was higher for the non-industry funded SRs than for the industry-funded SRs (0.62 vs. 0.36; p < .00001). Lower ratings for industry funded SRs were consistent across all but one AMSTAR 2 item, though significantly lower only for three specific items.

CONCLUSION

The methodological quality of SRs in vaccination is comparable to SRs in other fields, while it is still suboptimal. We are not able to provide a satisfactory explanation why industry funded SRs had a lower methodological quality than non-industry funded SRs over recent years. Industry funding is an important indicator of methodological quality for vaccine SRs and should be carefully considered when appraising SR quality.

The underlying mechanisms of cold exposure-induced ischemic stroke

Growing evidence suggests that cold exposure is to some extent a potential risk factor for ischemic stroke. At present, although the mechanism by which cold exposure induces ischemic stroke is not fully understood, some potential mechanisms have been mentioned. First, the seasonal and temperature variability of cerebrovascular risk factors (hypertension, hyperglycemia, hyperlipidemia, atrial fibrillation) may be involved. Moreover, the activation of sympathetic nervous system and renin-angiotensin system and their downstream signaling pathways (pro-inflammatory AngII, activated platelets, and dysfunctional immune cells) are also major contributors. Finally, the influenza epidemics induced by cold weather are also influencing factors that cannot be ignored. This article is the first to systematically and comprehensively describe the underlying mechanism of cold-induced ischemic stroke, aiming to provide more preventive measures and medication guidance for stroke-susceptible individuals in cold season, and also provide support for the formulation of public health policies.

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

The risk of stroke in patients with gout is high. The effect of vaccines in lowering the stroke risk in patients with gout remains unclear. We retrospectively analyzed 23,949 patients with gout (age ≥ 55 years) from the National Health Insurance Research Database over a 12-year period. The patients were divided into vaccinated (n = 11,649) and unvaccinated groups (n = 12,300). Overall, the vaccinated group had significantly lower risks of all stroke, hemorrhagic stroke, and ischemic stroke than the unvaccinated group (adjusted hazard ratio [aHR], 0.59 and 95% confidence interval [CI], 0.55–0.63; aHR, 0.60 and 95% CI, 0.49–0.73; and aHR, 0.60 and 95% CI, 0.55–0.65, respectively). The association appeared to be dose-dependent for both hemorrhagic and ischemic stroke (hemorrhagic stroke: aHR, 0.81 and 95% CI, 0.61–1.08; aHR, 0.80 and 95% CI, 0.62–1.02; and aHR, 0.37 and 95% CI, 0.28–0.48; ischemic stroke: aHR, 0.83 and 95% CI, 0.74–0.94; aHR, 0.73 and 95% CI, 0.65–0.81; and aHR, 0.42 and 95% CI, 0.38–0.47 for patients vaccinated 1, 2 or 3, and ≥4 times, respectively, during the follow-up period). Patients with a history of atrial fibrillation did not have a lower risk of hemorrhagic stroke even after receiving four vaccinations (aHR, 0.59; 95% CI, 0.25–1.38). Influenza vaccination was associated with a lower risk of all stroke in people with gout, and the association appeared to be dose-dependent.

Individual and Joint Effects of Influenza-Like Illness and Vaccinations on Stroke in the Young: A Case-Control Study

BACKGROUND:

Influenza-like illness (ILI) is an acute trigger for stroke, although joint effects of vaccinations and ILI have not yet been explored.

METHODS:

Data for our case-control study was obtained from MarketScan Commercial Claims and Encounters between 2008 and 2014. Patients 18 to 65 years old who experienced a stroke were matched on age and admission date to a control, defined as patients with head trauma or ankle sprain at an inpatient or emergency department visit. Exposures were ILI in the prior 30 days, and any type of vaccination during the year prior. Our outcome was ischemic and intracerebral hemorrhagic strokes identified using International Classification of Diseases, Ninth Revision (ICD-9 ) codes. Logistic regression models estimated adjusted odds ratios (aORs) controlling for preventive care visits, diabetes, valvular heart disease, smoking, alcohol abuse, obesity, and hypertension.

RESULTS:

We identified and matched 24 103 cases 18 to 44 years old and 141 811 45 to 65 years old. Those aged 18 to 44 years had increased stroke risk 30 days after ILI (aOR, 1.68 [95% CI, 1.51–1.86]) and reduced risk with any vaccination in the year prior (aOR, 0.92 [95% CI, 0.87–0.99]). Joint effects indicate that ILI was associated with increased stroke risk among those with (aOR, 1.41 [95% CI, 1.08–1.85]) and without (aOR, 1.73 [95% CI, 1.55–1.94]) vaccinations in the prior year ( P interaction =0.16). Among those aged 45 to 65 years, adjusted analyses indicate increased stroke risk for those with ILI (aOR, 1.32 [95% CI, 1.26–1.38]), although there was no effect of vaccinations (aOR, 1.00 [95% CI, 0.97–1.02]). Joint effects indicate that ILI was not associated with stroke among those with any vaccination (aOR, 1.07 [95% CI, 0.96–1.18]) but was associated with increased risk among those without vaccinations ([aOR, 1.39 [95% CI, 1.32–1.47]; P interaction <0.001).

CONCLUSIONS:

ILI was associated with increased stroke risk in the young and middle-aged, while vaccinations of any type were associated with decreased risk among the young. Joint effects of ILI and vaccinations indicate vaccinations can reduce the effect of ILI on stroke.

Therapeutic Trends of Cerebrovascular Disease during the COVID-19 Pandemic and Future Perspectives

As of May 2022, there have been more than 400 million cases (including re-infections) of the systemic acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), and nearly 5 million deaths worldwide. Not only has the coronavirus disease 2019 (COVID-19) pandemic been responsible for diagnosis and treatment delays of a wide variety of conditions, and overwhelmed the allocation of healthcare resources, it has impacted the epidemiology and management of cerebrovascular disease. In this narrative review, we summarize the changing paradigms and latest data regarding the complex relationship between COVID-19 and cerebrovascular disease. Paradoxically, although SARS-CoV-2 has been associated with many thrombotic complications—including ischemic stroke—there have been global declines in ischemic stroke and other cerebrovascular diseases. These epidemiologic shifts may be attributed to patient avoidance of healthcare institutions due to fear of contracting the novel human coronavirus, and also related to declines in other transmissible infectious illnesses which may trigger ischemic stroke. Despite the association between SARS-CoV-2 and thrombotic events, there are inconsistent data regarding targeted antithrombotics to prevent venous and arterial events. In addition, we provide recommendations for the conduct of stroke research and clinical trial planning during the ongoing COVID-19 pandemic, and for future healthcare crises.

Aneurysmal Subarachnoid Hemorrhage during the Shutdown for COVID-19

The aim was to evaluate hospitalization rates for aneurysmal subarachnoid hemorrhage (SAH) within an interdisciplinary multicenter neurovascular network (NVN) during the shutdown for the COVID-19 pandemic along with its modifiable risk factors. In this multicenter study, admission rates for SAH were compared for the period of the shutdown for the COVID-19 pandemic in Germany (calendar weeks (cw) 12 to 16, 2020), the periods before (cw 6–11) and after the shutdown (cw 17–21 and 22–26, 2020), as well as with the corresponding cw in the years 2015–2019. Data on all-cause and pre-hospital mortality within the area of the NVN were retrieved from the Department of Health, and the responsible emergency medical services. Data on known triggers for systemic inflammation, e.g., respiratory viruses and air pollution, were analyzed. Hospitalizations for SAH decreased during the shutdown period to one-tenth within the multicenter NVN. There was a substantial decrease in acute respiratory illness rates, and of air pollution during the shutdown period. The implementation of public health measures, e.g., contact restrictions and increased personal hygiene during the shutdown, might positively influence modifiable risk factors, e.g., systemic inflammation, leading to a decrease in the incidence of SAH.

Ιmmunity, Vascular Aging, and Stroke

Stroke is one of the most devastating manifestations of cardiovascular disease. Growing age, arterial hypertension, and atherosclerosis are identified as independent risk factors for stroke, primarily due to structural and functional alterations in the cerebrovascular tree. Recent data from in vitro and clinical studies have suggested that the immune system influences atherosclerosis, promoting vascular stiffness and vascular aging and contributing to ischemic stroke, intracranial haemorrhage and microbleeds, white matter disease, and cognitive decline. Furthermore, aging is related to a chronic low-grade inflammatory state, in which macrophage, neutrophils, natural killer (NK cells), and B and T lymphocytes act as major effectors of the immune-mediated cell responses. Moreover, oxidative stress and vascular inflammation are correlated with endothelial dysfunction, vascular aging, blood-brain barrier disruption, lacunar lesions, and neurodegenerative disorders. This review discusses the pathophysiological roles of fundamental cellular and molecular mechanisms of aging, including the complex interplay between them and innate immunity, as well as vascular dysfunction, arterial stiffness, atherosclerosis, atherothrombosis, systemic inflammation, and blood-brain barrier dysfunction.

Novel Technique to Measure Pulse Wave Velocity in Brain Vessels Using a Fast Simultaneous Multi-Slice Excitation Magnetic Resonance Sequence

In this study, we proposed a novel pulse wave velocity (PWV) technique to determine cerebrovascular stiffness using a 3-tesla magnetic resonance imaging (MRI) to overcome the various shortcomings of existing PWV techniques for cerebral-artery PWV, such as long scan times and complicated procedures. The technique was developed by combining a simultaneous multi-slice (SMS) excitation pulse sequence with keyhole acquisition and reconstruction (SMS-K). The SMS-K technique for cerebral-artery PWV was evaluated using phantom and human experiments. In the results, common and internal carotid arteries (CCA and ICA) were acquired simultaneously in an image with a high temporal resolution-of 48 ms for one measurement. Vascular signals at 500 time points acquired within 30 s could generate pulse waveforms of CCA and ICA with 26 heartbeats, allowing for the detection of PWV changes over time. The results demonstrated that the SMS-K technique could provide more PWV information with a simple procedure within a short period of time. The procedural convenience and advantages of PWV measurements will make it more appropriate for clinical applications.

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

Background

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

Objective

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

Methods

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

Results

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

Conclusions

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

Periprocedural complications in patients with SARS-CoV-2 infection compared to those without infection: A nationwide propensity-matched analysis

BACKGROUND

Reports on emergency surgery performed soon after a COVID-19 infection that are not controlled for premorbid risk-factors show increased 30-day mortality and pulmonary complications. This contributed to a virtual cessation of elective surgery during the pandemic surge. To inform evidence-based guidance on the decisions for surgery during the recovery phase of the pandemic, we compare 30-day outcomes in patients testing positive for COVID-19 before their operation, to contemporary propensity-matched COVID-19 negative patients undergoing the same procedures.

METHODS

This prospective multicentre study included all patients undergoing surgery at 170 Veterans Health Administration (VA) hospitals across the United States. COVID-19 positive patients were propensity matched to COVID-19 negative patients on demographic and procedural factors. We compared 30-day outcomes between COVID-19 positive and negative patients, and the effect of time from testing positive to the date of procedure (≤10 days, 11-30 days and >30 days) on outcomes.

RESULTS

Between March 1 and August 15, 2020, 449 COVID-19 positive and 51,238 negative patients met inclusion criteria. Propensity matching yielded 432 COVID-19 positive and 1256 negative patients among whom half underwent elective surgery. Infected patients had longer hospital stays (median seven days), higher rates of pneumonia (20.6%), ventilator requirement (7.6%), acute respiratory distress syndrome (ARDS, 17.1%), septic shock (13.7%), and ischemic stroke (5.8%), while mortality, reoperations and readmissions were not significantly different. Higher odds for ventilation and stroke persisted even when surgery was delayed 11-30 days, and for pneumonia, ARDS, and septic shock >30 days after a positive test.

DISCUSSION

30-day pulmonary, septic, and ischaemic complications are increased in COVID-19 positive, compared to propensity score matched negative patients. Odds for several complications persist despite a delay beyond ten days after testing positive. Individualized risk-stratification by pulmonary and atherosclerotic comorbidities should be considered when making decisions for delaying surgery in infected patients.

Determinants of Influenza Vaccine Uptake in Patients With Cardiovascular Disease and Strategies for Improvement

Cardiovascular disease (CVD) is the leading cause of death and disability worldwide. Influenza infection is associated with an increased risk of cardiovascular events (myocardial infarction, stroke, and heart failure exacerbation) and mortality, and all‐cause mortality in patients with CVD. Infection with influenza leads to a systemic inflammatory and thrombogenic response in the host body, which further causes destabilization of atherosclerotic plaques. Influenza vaccination has been shown to be protective against cardiovascular and cerebrovascular events in several observational and prospective studies of at‐risk populations. Hence, many international guidelines recommend influenza vaccination for adults of all ages, especially for individuals with high‐risk conditions such as CVD. Despite these long‐standing recommendations, influenza vaccine uptake among US adults with CVD remains suboptimal. Specifically, vaccination uptake is strikingly low among patients aged <65 years, non‐Hispanic Black individuals, those without health insurance, and those with diminished access to healthcare services. Behavioral factors such as perceived vaccine efficacy, vaccine safety, and attitudes towards vaccination play an important role in vaccine acceptance at the individual and community levels. With the ongoing COVID‐19 pandemic, there is a potential threat of a concurrent epidemic with influenza. This would be devastating for vulnerable populations such as adults with CVD, further stressing the need for ensuring adequate influenza vaccination coverage. In this review, we describe a variety of strategies to improve the uptake of influenza vaccination in patients with CVD through improved understanding of key sociodemographic determinants and behaviors that are associated with vaccination, or the lack thereof. We further discuss the potential use of relevant strategies for COVID‐19 vaccine uptake among those with CVD.

[Lifestyle changes for stroke prevention]

Changes of lifestyle have a substantial effect on stroke prevention, especially in high-risk patients. Maintaining a healthier lifestyle can have greater effects than most pharmacological therapies of cardiovascular prevention. For example, increasing the amount of physical activity, adopting a healthy diet, limiting alcohol consumption and quitting smoking are associated with a 70 % decrease in stroke risk. Despite the abundance of observational data and meta-analyses assessing the association of different lifestyle changes and stroke risk, the literature frequently lacks evidence from randomized controlled clinical trial. This article will provide an overview of various forms of lifestyle changes and summarize their potential to modify the risk of stroke.

[Neurovascular manifestations of COVID‑19]

Even early at the beginning of the coronavirus disease 2019 (COVID‑19) pandemic, stroke was described as a manifestation or complication of infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Current meta-analyses reported a stroke rate of approximately 1.5%. Stroke in COVID‑19 positive patients occurs more frequently in severe courses of the infection and in older patients with cardiovascular comorbidities; however, young patients without cardiovascular risk factors are also not uncommonly affected. The mechanisms of stroke are predominantly embolic. The thrombi frequently occlude large intracranial vessels and in more than 20% affect multiple vascular territories, whereas infarctions due to small vessel disease are uncommon. The exact source of the embolism remains cryptogenic in more than 40% of patients. The mortality caused by the co-occurrence of a SARS-CoV‑2 infection and a stroke exceeds 15-30%. While acute stroke treatment was severely affected in some European regions, the rates of recanalization treatment in Germany largely remained stable during the first pandemic wave; however, 20-30% fewer patients with minor stroke and transient ischemic attacks (TIA) presented to hospitals during the first wave in spring 2020. The present narrative review summarizes the current evidence regarding the epidemiology and pathogenesis of stroke associated with COVID‑19 and describes the effect of the pandemic so far on the provision of acute stroke treatment.

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.

Differences in healthcare visit frequency and type one year prior to stroke among young versus middle-aged adults

Background

The incidence and prevalence of stroke among the young are increasing in the US. Data on healthcare utilization prior to stroke is limited. We hypothesized those < 45 years were less likely than those 45–65 years old to utilize healthcare in the 1 year prior to stroke.

Methods

Patients 18–65 years old who had a stroke between 2008 and 2013 in MarketScan Commercial Claims and Encounters Databases were included. We used descriptive statistics and logistic regression to examine healthcare utilization and risk factors between age groups 18–44 and 45–65 years. Healthcare utilization was categorized by visit type (no visits, inpatient visits only, emergency department visits only, outpatient patient visits only, or a combination of inpatient, outpatient or emergency department visits) during the year prior to stroke hospitalization.

Results

Of those 18–44 years old, 14.1% had no visits in the year prior to stroke compared to 11.2% of individuals aged 45–65 [OR = 1.30 (95% CI 1.25,1.35)]. Patients 18–44 years old had higher odds of having preventive care procedures associated with an outpatient visit and lower odds of having cardiovascular procedures compared to patients aged 45–65 years. Of stroke patients aged 18–45 and 45–65 years, 16.8 and 13.2% respectively had no known risk for stroke.

Conclusions

Patients aged 45–65 were less commonly seeking preventive care and appeared to be seeking care to manage existing conditions more than patients aged 18–44 years. However, as greater than 10% of both age groups had no prior risk, further exploration of potential risk factors is needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-06064-5.

Knowledge, Attitudes and Practices of Flu Vaccination in Hemodialysis Patients

BACKGROUND

Hemodialysis (HD) patients have an increased risk of morbidity and mortality due to infections. Despite the positive effect of vaccinations, the implementation of this method of prophylaxis is low.

OBJECTIVES

This study aimed to explore the knowledge, attitudes and practices of flu vaccination among HD patients of two different dialysis centers.

METHODS

A total of 193 patients (mean age 63.6 years), who voluntarily agreed to participate in an anonymous survey related to influenza vaccination, were enrolled in this cross-sectional study.

RESULTS

A total of 45% of patients declared that they took regular, annual flu vaccination. In this group, 87.4% believed that vaccinations were effective. This opinion strongly correlated with the frequency of regular vaccinations (r = 0.56, p < 0.01). Multivariate logistic regression revealed that this opinion is an independent predictor of regular vaccinations with adjusted OR 9.86 (95% CI 4.36, 22.33). Groups of patients who had been irregularly or never vaccinated reject vaccinations for the following reasons: fear of adverse events-29.2%, conviction that vaccination was ineffective-26.4%, and lack of information about vaccination-22.6%.

CONCLUSION

Knowledge among HD patients about the benefits of vaccinations is poor. Therefore, educational activities are required. Active vaccination promotion and education of patients rejecting this method of prevention play a key role in improving standards of care for HD patients.

Stroke in Coronavirus Disease 2019: A Systematic Review

Background and Purpose

Various neurological findings including stroke in patients with coronavirus disease 2019 (COVID-19) have been described, although no clarity exists regarding the nature and pattern of this association. This systematic review aims to report the characteristics of stroke in patients with COVID-19.

Methods

Three authors independently searched Web of Science, Embase, Scopus, and PubMed starting from inception up to May 22, 2020. The data for individual patients was extracted where available from published reports including clinical and laboratory parameters and analysed for any significant associations between variables.

Results

We identified 30 relevant articles involving 115 patients with acute or subacute stroke with COVID-19. The mean±standard deviation age was 62.5±14.5 years. Stroke was ischemic in majority of the patients (101 [87.8%]). Hypertension (42 [42%]), dyslipidaemia (24 [26.1%]), and diabetes (23 [23.2%]) were the major vascular risk factors. Most of the patients (80 [85.1%]) had COVID-19 symptoms at the time of stroke with a median interval of 10 days to stroke from the diagnosis of COVID-19. Three-fourths (86 [74.8%]) of the patients were critically ill which frequently delayed the diagnosis of stroke. High levels of D-dimer, and ferritin were observed in these patients. Patients with COVID-19 and stroke had a high mortality (47.9%). Factors associated with mortality were intensive care unit admission, having two or more vascular risk factors, particularly smoking and high levels of D-dimer, C-reactive protein, and lactate dehydrogenase.

Conclusions

The association between stroke and COVID-19 is probably multifactorial including an amalgamation of traditional vascular risk factors, proinflammatory and a prothrombotic state. Prospectively collected data is required in the future to confirm this hypothesis.

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.

The impact of influenza vaccination in patients with cardiovascular disease: An overview of systematic reviews

Whether influenza vaccination can play a prognostic role in patients with cardiovascular (CV) disease (coronary artery disease (CAD), heart failure, stroke, peripheral artery disease (PAD)) is still not completely well-established. We conducted this overview of systematic reviews (SR) evaluating the effects of influenza vaccination in secondary prevention of CV disease. An electronic search was performed in the MEDLINE (to November 2019). Eligibility criteria included SR evaluating the effect of influenza vaccination in patients with CV disease. The risk of bias of the included systematic reviews was evaluated using the ROBIS tool. All-cause mortality, CV mortality, major adverse cardiovascular events (MACE) and hospitalizations were evaluated. Whenever required, data were recalculated through a random-effects meta-analysis to obtain pooled data for the patients at secondary CV prevention. The search process yielded four SR: two in CAD, one in heart failure and one in stroke. There were no SR evaluating the vaccine in PAD. The risk of bias was unclear (2 SR) and high (2 SR). Influenza vaccination in patients with CAD showed a risk reduction in all-cause mortality (data recalculated), cardiovascular mortality and MACE, particularly in patients with recent acute coronary syndrome. In patients with heart failure, vaccination was associated with a decreased risk of all-cause mortality. There was a non-significant trend in recurrent stroke risk reduction in patients with previous stroke. The available evidence suggests that influenza vaccination was associated with a protective effect in CAD and HF patients. However, these results need to be clarified with higher quality evidence studies.

COVID-19 and Stroke: Incidental, Triggered or Causative

Stroke is a serious neurological comorbidity observed during the ongoing COVID-19 (coronavirus associated disease 2019) pandemic caused by SARS-CoV-2 (severe acute respiratory syndrome, corona virus 2) and includes ischemic stroke, intracerebral haemorrhage and cerebral venous thrombosis. We reviewed factors that could potentially contribute to the occurrence of stroke among patients with COVID-19. There could be an interaction between the conventional risk factors of stroke, infection, systemic inflammatory response and plaque destabilisation. Inflammatory markers, D-dimer elevation and increased cytokine activity have been observed in patients with COVID-19. Other probable contributing factors include cardiac injury leading to embolism, a prothrombotic state and a possibility of direct neuroinvasive potential causing vasculopathy. Data from stroke patients gathered in large multicentric cohorts could help shed more light on the occurrence, behaviour, aetiology, pathophysiology, biomarkers and outcomes of stroke occurring during the ongoing pandemic.

Infections causing stroke or stroke-like syndromes

BACKGROUND

Stroke has relevant morbidity and mortality despite appropriate treatments and early diagnosis. Beside common risk factors such as diabetes and atrial fibrillation, infections can be involved in stroke pathogenesis, probably causing a systemic release of cytokines and other inflammatory mediators, triggering a latent pro-thrombotic state or damaging the vascular endothelium. In other cases, infections can occur as stroke-like syndromes, requiring a high grade of suspicion to avoid a delay in establishing a correct diagnosis.

RESULTS

Treatment of stroke or stroke-like syndromes of infectious origin can be difficult. When a previous infective event triggers stroke, Alteplase administration can be associated with a higher incidence of bleeding and the extension of the ischaemic area can be major than expected. On the other hand, when stroke is part of some infectious diseases' presentation as in endocarditis, bacterial or tuberculous meningitis and meningo-vascular syphilis, a correct diagnosis can be difficult. The management of these stroke-like syndromes is not standardised because common treatments proven to be effective for patients with stroke of vascular origin can worsen the prognosis, as it can be demonstrated after to be incorrect Alteplase administration to patients with endocarditis with septic embolism to the brain is associated with an increase of the risk of haemorrhage.

CONCLUSIONS

Stroke or stroke-like syndrome of infectious origin can be observed in an important proportion of case presenting with sensory-motor deficit of unknown origin; their accurate diagnosis has a considerable impact in terms of treatment choices and outcome.

Risk Of Urticaria In Geriatric Stroke Patients Who Received Influenza Vaccination: A Retrospective Cohort Study

Objective

Urticaria is a mast cell-related disease caused severe itching and the lifetime prevalence of urticaria is about 20% in general population. Our purpose is to evaluate risk of urticaria in geriatric stroke patients received influenza vaccination (IV).

Methods

In a cohort of 192,728 patients with newly diagnosed stroke aged over 65 years obtained from 23 million people in Taiwan’s National Health Insurance between 2000 and 2008, we identified 9890 stroke patients who received IV and 9890 propensity score-matched stroke patients who did not receive IV. Controlling for immortal time bias, both the IV and non-IV groups were followed for one year. Urticaria events were identified during the follow-up period. We calculated the adjusted rate ratios (RRs) and 95% confidence intervals (CIs) of the one-year risk of urticaria associated with IV.

Results

During the follow-up period of one year, stroke patients with IV had a significantly higher risk of urticaria compared with non-IV stroke patients (RR 1.81, 95% CI 1.47–2.23). An increased risk of urticaria in stroke patients with IV was noted in both sexes, patients 65–84 years of age, patients with comorbid medical conditions, and various time intervals of follow-up. Vaccinated stroke patients with hemorrhage (RR 4.00, 95% CI 1.76–9.10) and those who received intensive care (RR 5.14, 95% CI 2.32–11.4) had a very high risk of urticaria compared with those without IV.

Conclusion

Receiving IV may be associated with an increased risk of urticaria in stroke patients. We could not infer the causality from the current results because of this study’s limitations. Future investigations are needed to evaluate the possible mechanism underlying the association between IV and urticaria.

Ischemic stroke and infectious diseases in low-income and middle-income countries

PURPOSE OF REVIEW

To address the important relationships between stroke and infection, focusing on the most frequent infections found in low-income and middle-income countries.

RECENT FINDINGS

Stroke is one of the leading causes of mortality and disability worldwide, with a great proportion of the stroke burden occurring in low-income and middle-income countries. Infectious diseases are still a great health problem in developing countries and it is possible that the proportion of infection-related strokes is greater in these nations. Infectious diseases and stroke have a bidirectional relationship. Common infections may act as risk factors and can trigger stroke through different mechanisms in their acute phase. Several intracranial and systemic infections can cause stroke as a direct complication, such as Chagas disease, neurosyphilis, tuberculous meningitis, and neurocysticercosis. These conditions are of particular interest to low-income and middle-income countries, but also relevant to high-income nations because of increasing migration. Finally, infection is a frequent poststroke complication, with great impact in the patient outcome.

SUMMARY

Infectious diseases and stroke are common problems in low-income and middle-income countries. More studies are necessary to fully elucidate the real impact of infectious diseases on stroke burden, especially in countries where epidemiological data are still scarce.

Influenza vaccination and 1-year risk of myocardial infarction, stroke, heart failure, pneumonia, and mortality among intensive care unit survivors aged 65 years or older: a nationwide population-based cohort study

PURPOSE

We examined whether influenza vaccination affects 1-year risk of myocardial infarction, stroke, heart failure, pneumonia, and death among intensive care unit (ICU) survivors aged ≥ 65 years.

METHODS

Danish Intensive Care Database data on all elderly ( ≥ 65 years) patients hospitalized in Danish ICUs in the period 2005-2015, and subsequently discharged, were linked with data from other medical registries, including data on uptake of the seasonal influenza vaccine. We computed these patients' 1-year risk of hospitalization for myocardial infarction, stroke, heart failure, or pneumonia, and their 1-year risk of all-cause mortality. Hazard ratios (HRs) with 95% confidence intervals (CIs) were computed using Cox proportional hazards regression, with adjustment and propensity score matching applied to handle confounding.

RESULTS

The study included 89,818 ICU survivors. The influenza vaccinated patients (n = 34,871, 39%) were older, had more chronic diseases, and used more prescription medications than the unvaccinated patients. Adjusted 1-year mortality was decreased among the vaccinated versus the unvaccinated patients (19.3% versus 18.8%; adjusted HR, 0.92; 95% CI 0.89-0.95). Influenza vaccination was also associated with a decreased risk of stroke (adjusted HR, 0.84; 95% CI 0.78-0.92), but only a small, non-significantly decreased risk of myocardial infarction (adjusted HR, 0.93; 95% CI 0.83-1.03). There was no association between vaccination and subsequent hospitalization for heart failure or pneumonia. Propensity score matched analyses confirmed these findings.

CONCLUSIONS

Compared with the unvaccinated ICU survivors, the influenza vaccinated ICU survivors had a lower 1-year risk of stroke and a lower 1-year risk of death, whereas no substantial association was observed for the risk of hospitalization for myocardial infarction, heart failure, or pneumonia. Our findings support influenza vaccination of individuals aged ≥ 65 years.

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.

[Mortality due to cerebrovascular disease among the elderly and vaccination against influenza: São Paulo State, Brazil, 1980-2012]

This study describes the trend of the coefficients of mortality due to cerebrovascular diseases (CbVD) among the elderly in São Paulo State, Brazil, from 1980 to 2012, before and after influenza vaccination campaigns, and identifies change points. It is an ecological, time-series study carried out with death data from the Health Ministry's Mortality Information System and population data from the Brazilian Institute of Geography and Statistics. We used linear, polynomial and joinpoint regression models in the data analysis. Between 1980 and 2012, there were 480,955 deaths due to CbVD. The mean mortality coefficients decreased for both sexes in all age groups we analyzed, with the greatest reduction in the older ages and male sex. We observed a significant reduction in the mortality trend in 1998 for male sex in the age group 60-69 years (annual percent change - APC = -3%, 95%CI: -4.3; -1.6) and for all elderly (APC = -3.8%, 95%CI: -4.4; -3.1). Considering the period as a whole, we did not observe change points for the age group 70-79 (average annual percent change - AAPC = -3.3%, 95%CI: -3.5; -3.1) and, for male sex, for the group ≥ 80 years (AAPC = -2.9%, 95%CI: -3.1; -2.6). For all elderly, the mean percentage reduction was of 3.1% per year (AAPC = -3.1%, 95%CI: -3.5; -2.7). Results show a reduction in the mortality due to CbVD in the period, with different percentage variations in coefficient reduction. The study's findings add information to the debate regarding possible effects of vaccination campaigns in reducing mortality due to CbVD among the elderly.

Protective effect of influenza vaccination on outcomes in geriatric stroke patients: A nationwide matched cohort study

BACKGROUND AND AIMS

The effects of influenza vaccination (IV) on stroke outcomes are unclear. The purpose of this study is to evaluate the outcomes after stroke in elderly individuals who have received an IV.

METHODS

We used Taiwan's National Health Insurance Research Database 2000-2009 claims data to conduct a nested stroke cohort study including 148,909 hospitalized stroke patients aged 66 years and older. Using a matching procedure by propensity score, we selected 25,248 stroke patients with IV and 25,248 stroke patients without IV for comparison. Logistic regression was used to calculate the odds ratios (ORs) and 95% CIs of post-stroke complications and in-hospital mortality associated with IV.

RESULTS

Stroke patients with IV had significantly lower risks of post-stroke pneumonia (OR = 0.79; 95% CI, 0.74-0.83), septicemia (OR = 0.78; 95% CI, 0.70-0.86), urinary tract infection (OR = 0.87; 95% CI, 0.83-0.92), and 30-day in-hospital mortality (OR = 0.60; 95% CI, 0.54-0.67) compared with non-IV stroke patients. Vaccinated stroke patients also had shorter hospital stays (p < 0.0001) and less medical expenditures (p < 0.0001) during stroke admission than the control group. Lower rates of post-stroke adverse events in patients with IV were noted in both sexes of all age groups with various types of stroke.

CONCLUSIONS

Stroke patients with IV showed fewer complications and lower mortality compared with non-IV patients. These findings suggest the urgent need to promote IV for this susceptible population of stroke patients.

The association of adult vaccination with the risk of cerebrovascular ischemia: A systematic review and meta-analysis

There is mounting evidence supporting infection as an independent risk factor for ischemic stroke (IS), while preliminary data indicate that vaccination may prevent IS. We performed a systematic review and meta-analysis of available randomized clinical trials (RCTs) or prospective observational cohorts reporting associations of influenza vaccination (IV) and/or pneumococcal vaccination (PV) with IS. We identified a total of 12 studies (543,311 patients; 47.4% vaccinated). Vaccination was not related to the risk of IS (RR=1.06, 95%CI: 0.74-1.51, p=0.77), with no significant differences (p=0.26) among RCTs (RR=0.66, 95%CI: 0.30-1.47) and observational studies (RR=1.11, 95%CI: 0.76-1.61). Evidence of considerable heterogeneity was identified within observational studies (I²=98%), but not within RCTs (I²=0%). In subgroup analyses according to vaccination type, IV was associated with a significantly lower risk of IS (RR=0.87, 95%CI: 0.79-0.96, p=0.004) with moderate evidence of heterogeneity (I²=53%). No association was seen for PV (RR=1.38, 95%CI: 0.60-3.16, p=0.45), where considerable heterogeneity was identified (I²=97%). In the additional adjusted analyses of observational studies, vaccination tended to be associated with lower risk of IS (HRadjusted=0.87; 95%CI: 0.75-1.01; p=0.07). The findings of this meta-analysis indicate that IV may be associated with a lower risk of IS. This association was not reproduced for PV or the combination of two vaccines. Substantial heterogeneity was detected across observational studies for all outcome events, while moderate to low heterogeneity was identified across included RCTs. These preliminary findings require independent validation in large RCTs.