Benefits Of Influenza Vaccination Research Articles

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

BackgroundInfluenza 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. MethodsWe 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. ResultsA 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. ConclusionsVaccinated 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.

Perioperative Influenza Vaccination: opportunities and strategies to meet the global call to action

Influenza vaccination is a proven strategy vital to the promotion of population health. Global, national, and local healthcare organizations advise broad administration of seasonal influenza vaccination to occur at every opportunity. Despite established benefits of influenza vaccination and the global call to increase vaccination rate, multiple barriers beyond vaccine hesitancy have produced a gap between goal and actual influenza vaccine coverage. Proposed solutions to address these issues include developing context specific strategies that integrate with other healthcare services to target sub-populations of patients. One such strategy is influenza vaccination during the perioperative period, which is the continuum of care during the preoperative, intraoperative, and postoperative phases of care. Historical approaches to perioperative vaccination have been two- fold. The first being a conservative approach, prioritizing the need to ‘first do no harm’, that avoids potential risks of misinterpretation of vaccine related adverse events as perioperative complications and immunomodulation impacting efficacy of immunization. The second being a liberal approach, prioritizing the global call to use every opportunity to vaccinate with individual and population health benefits of vaccination outweighing any low and theoretical risks posed by conservative concerns. Modern strategies balance these concerns and target context specific opportunities to apply perioperative influenza vaccination through evidence-based approaches in the preoperative and intraoperative phases of care. Additionally, opportunity to administer flu vaccine in the postoperative phase are also discussed. Global perioperative healthcare providers are called to action and encouraged to utilize and build upon these strategies to meet the global need of increasing influenza vaccination. The patients we serve deserve our advancements in protecting them.

Calculation of Social Benefits of Influenza Vaccination based on Statistical Data

The goal we set in our study has had no precedent either in the Hungarian or in the international literature: our intention was to quantify the effectiveness of influenza vaccination based on facts, and to define the number of non-occurred diseases as a result of vaccination. We evaluated data from the influenza season of 2018/2019 in our study. We analyzed the available data on population, vaccination and the number of diseases, and drew objective conclusions therefrom. It was a problem that the basic data appeared in different data sets for different age groups, so we had to find a consensus between them, and establish comparable age groups. Ultimately, we defined three distinct age groups: the age group of minors (0-18 years), the economically active (19-59 years) and the age group of over 60 years. These three age groups became well distinguishable by population, vaccination, and morbidity. We described the influenza disease in general, the characteristics and variability of the influenza virus. We defined the typically affected age group, the number of patients to be treated, the trends for the past 5-10 years. The presented facts, numbers, the results of the calculations, and the conclusions drawn clearly show – excluding subjectivity – the preventive effect and effectiveness of vaccination, which was quantified for the first time in Hungarian literature.

Effect of a nationwide intervention of electronic letters with behavioural nudges on influenza vaccination in older adults in Denmark

Worldwide influenza epidemics result in an estimated 3–5 million cases of severe illness, and 290 000–650 000 respiratory deaths annually. 1 WHOInfluenza (seasonal). World Health Organization. https://www.who.int/news-room/fact-sheets/detail/influenza-(seasonal)Date accessed: February 19, 2023 Google Scholar Influenza also leads to high costs from direct medical expenses and lost productivity. 2 Putri W Muscatello DJ Stockwell MS Newall AT Economic burden of seasonal influenza in the United States. Vaccine. 2018; 36: 3960-3966 Crossref PubMed Scopus (212) Google Scholar Influenza vaccination is the single most important preventive measure against influenza, and as such is recommended worldwide. 1 WHOInfluenza (seasonal). World Health Organization. https://www.who.int/news-room/fact-sheets/detail/influenza-(seasonal)Date accessed: February 19, 2023 Google Scholar Adults aged 65 years or older are at particularly high risk for severe outcomes related to influenza. 1 WHOInfluenza (seasonal). World Health Organization. https://www.who.int/news-room/fact-sheets/detail/influenza-(seasonal)Date accessed: February 19, 2023 Google Scholar However, annual vaccination rates of older adults vary globally from less than 10% up to 80%. 3 Organisation for Economic Co-operation and DevelopmentInfluenza vaccination rates. https://data.oecd.org/healthcare/influenza-vaccination-rates.htmDate accessed: February 19, 2023 Google Scholar Electronic nudges to increase influenza vaccination uptake in Denmark: a nationwide, pragmatic, registry-based, randomised implementation trialElectronically delivered letters highlighting potential cardiovascular benefits of influenza vaccination or sent again as a reminder significantly increased vaccination uptake across Denmark. Although the magnitude of effectiveness was modest, the low-touch, inexpensive, and highly scalable nature of these electronic letters might be informative for future public health campaigns. Full-Text PDF

Effect of Electronic Nudges on Influenza Vaccination Rate in Older Adults With Cardiovascular Disease: Prespecified Analysis of the NUDGE-FLU Trial.

Influenza vaccines have been demonstrated to effectively reduce the incidence of influenza infection and potentially associated risks of cardiovascular events in patients with cardiovascular disease (CVD). Despite strong guideline and public health endorsements, global influenza vaccination rates in patients with CVD are highly variable. This prespecified analysis of NUDGE-FLU (Nationwide Utilization of Danish Government Electronic Letter System for Increasing Influenza Vaccine Uptake) examined the effect of digital behavioral nudges on influenza vaccine uptake based on the presence of CVD. NUDGE-FLU was a randomized, pragmatic, nationwide, register-based trial that included Danish citizens 65 years of age or older during the 2022 to 2023 influenza season. Households were randomized in a 9:1:1:1:1:1:1:1:1:1 ratio to usual care or 9 electronic letters with designs based on behavioral concepts. Danish nationwide registers were used to collect baseline and outcome data. The primary end point was receipt of an influenza vaccine on or before January 1, 2023. The effects of the intervention letters were examined according to the presence of CVD and across cardiovascular subgroups that included heart failure, ischemic heart disease, and atrial fibrillation. Of 964 870 NUDGE-FLU participants from 691 820 households, 264 392 (27.4%) had CVD. During follow-up, 83.1% of participants with CVD versus 79.2% of participants without CVD received an influenza vaccination (P<0.001). Compared with usual care, a letter emphasizing the potential cardiovascular benefits of influenza vaccination increased vaccination rates; this effect was consistent in participants with CVD (absolute difference, +0.60 percentage points [99.55% CI, -0.48 to 1.68]) and without CVD (+0.98 percentage points [99.55% CI, 0.27-1.70; P for interaction=0.41). A repeated letter strategy with a reminder follow-up letter 14 days later was also effective in increasing influenza vaccination, irrespective of CVD (CVD: absolute difference, +0.80 percentage points [99.55% CI, -0.27 to 1.86]; no CVD: +0.67 percentage points [99.55% CI, -0.06 to 1.40]; P for interaction=0.77). Effectiveness of both nudging strategies was consistent across all major CVD subgroups. None of the other 7 nudging strategies were effective, regardless of CVD status. Electronic letter interventions emphasizing the potential cardiovascular benefits of influenza vaccination and using a reminder letter strategy were similarly beneficial in increasing influenza vaccination rates among older adults with and without CVD and across cardiovascular subgroups. Electronic nudges may improve influenza vaccine uptake in individuals with CVD. URL: https://www. gov; Unique identifier: NCT05542004.

Electronic nudges to increase influenza vaccination uptake in Denmark: a nationwide, pragmatic, registry-based, randomised implementation trial

Influenza vaccination rates remain suboptimal despite effectiveness in preventing influenza infection and related complications. We investigated whether behavioural nudges, delivered via a governmental electronic letter system, would increase influenza vaccination uptake among older adults in Denmark. We did a nationwide, pragmatic, registry-based, cluster-randomised implementation trial during the 2022-23 influenza season in Denmark. All Danish citizens aged 65 years or older or turning 65 years by Jan 15, 2023 were included. We excluded individuals living in nursing homes and individuals who had an exemption from the Danish mandatory governmental electronic letter system. Households were randomly assigned (9:1:1:1:1:1:1:1:1:1) to usual care or nine different electronic letters designed on the basis of different behavioural nudging concepts. Data were sourced from nationwide Danish administrative health registries. The primary endpoint was receipt of influenza vaccination on or before Jan 1, 2023. The primary analysis assessed an analytical set of one randomly selected individual per household, and a sensitivity analysis included all randomly assigned individuals and accounted for within-household correlation. The trial is registered with ClinicalTrials.gov, NCT05542004. We identified 1 232 938 individuals aged 65 years or older in Denmark and excluded 56 436 (4·6%) individuals living in nursing homes and 211 632 (17·2%) with an exemption from the electronic letter system. We randomly assigned 964 870 (78·3%) participants across 691 820 households. Compared with usual care, influenza vaccination rates were higher in the group receiving an electronic letter highlighting potential cardiovascular benefits of vaccination (81·00% vs 80·12%; difference 0·89 percentage points [99·55% CI 0·29-1·48]; p<0·0001) and the group receiving repeated letters at randomisation and at day 14 (80·85% vs 80·12%; difference 0·73 percentage points [0·13-1·34]; p=0·0006). These strategies improved vaccination rates across major subgroups including those with and without established cardiovascular disease. The cardiovascular gain-framed letter was particularly effective among participants who had not been vaccinated for influenza in the previous season (pinteraction=0·0002). A sensitivity analysis of all randomly assigned individuals accounting for within-household clustering yielded similar findings. Electronically delivered letters highlighting potential cardiovascular benefits of influenza vaccination or sent again as a reminder significantly increased vaccination uptake across Denmark. Although the magnitude of effectiveness was modest, the low-touch, inexpensive, and highly scalable nature of these electronic letters might be informative for future public health campaigns. Sanofi.

Knowledge, attitudes and practices of health care workers in a cardiology department on influenza vaccination.

Evidence has accrued that influenza vaccination may be effective in preventing myocardial infarction (MI). However, vaccination rates in both adults and health care workers (HCW) are low, and hospitalisation is often a missed opportunity for vaccination. We hypothesised that knowledge, attitude and practices of health care workers regarding vaccination impacts vaccine uptake in hospitals. The cardiac ward admits high-risk patients, many of whom are indicated for influenza vaccine, especially those caring for patients with acute MI. To understand the knowledge, attitudes, and practices of HCW in cardiology ward within a tertiary institution, on influenza vaccination. We used focus group discussions with HCW caring for AMI patients in an acute cardiology ward, to explore the knowledge, attitudes, and practices of HCW regarding influenza vaccination for patients under their care. Discussions were recorded, transcribed, and thematically analysed using NVivo software. In addition, participants completed a survey on their knowledge and attitudes towards the uptake of influenza vaccination. A lack of awareness regarding the associations between influenza, vaccination and cardiovascular health was identified amongst HCW. Participants did not routinely discuss the benefits of influenza vaccination or recommend influenza vaccinations to patients under their care; this may be due to a combination of a lack of awareness, not seeing it as part of their job and workload issues. We also highlighted difficulties in access to vaccination, and concerns of adverse reactions to the vaccine. There is limited awareness among HCW of the role of influenza on cardiovascular health and the benefits of influenza vaccine in the prevention of cardiovascular events. Improved vaccination of at-risk patients in hospital may need active engagement of HCW. Improving the health literacy of HCW regarding the benefits of vaccination as a preventative strategy may result in better health care outcomes for cardiac patients.

Vaccines and cardiovascular outcomes: lessons learned from influenza epidemics.

Cardiovascular disease (CVD) is the leading cause of death in the world and is largely preventable. An increasing amount of evidence suggests that annual influenza vaccination reduces CVD-related morbidity and mortality. Despite various clinical guidelines recommending annual influenza vaccination for the general population for influenza-like illness risk reduction, with a particular emphasis on people with CVD, vaccination rates fall consistently below the goal established by the World Health Organization. This review outlines the importance of influenza vaccination, mechanisms of cardiovascular events in influenza, summarizing the available literature on the effects of influenza vaccine in CVD and the benefits of influenza vaccine during the COVID-19 pandemic.

Myocardial infarction and viral triggers: what do we know by now?

Myocardial infarction (MI) is an acute clinical manifestation ischaemic heart disease, which is the leading cause of death worldwide. Infections also have an important burden worldwide, with lower respiratory infections being the worldwide leading cause of death due to communicable diseases. The relationship of MI with viral respiratory infections (including influenza and SARS-CoV-2) as a trigger has been well documented with significant associations. These infections can lead to Type 1 MI, where inflammation and vascular dysfunction, as well as the increased prothrombotic environment lead to atherothrombosis. Type 2 MI may also occur due to an imbalance of oxygen/blood supply and myocardial demand (hypoxaemia, fever, and tachycardia). The data from randomized controlled trials showing a potential benefit of influenza vaccination in coronary artery disease patients should not be ignored. This can be considered a further argument for the association of viral infections (influenza in particular) and MI.

Effect of Influenza Vaccination in Patients with Cardiovascular Disease: An Updated Meta-Analysis of Randomized Controlled Trials

Background: Influenza is a major cause of morbidity and mortality in patients with cardiovascular disease (CVD). The aim of this updated systematic review and meta-analysis was to evaluate the effect of influenza vaccination (IV) on morbidity and morbidity in adult patients with CVD. Methods: We conducted a systematic review and meta-analysis (PubMed, Cochrane Library, International Clinical Trials Registry Platform, and manual search of conference presentations) of randomized clinical trials published up to April 2022 analyzing whether IV reduced all-cause mortality in adult patients with CVD, including heart failure (HF) and coronary artery disease (CAD), compared with patients who were not vaccinated. Results: A total of six clinical trials comprising 9316 patients were analyzed. Five trials included CAD patients, and one trial included HF patients. Mean follow-up was 16 ± 9.7 months. Influenza vaccine was associated with a reduction of mortality compared to controls: relative risk (RR) 0.67, 95% confidence interval (95% CI), 0.47-0.95; p = 0.03; I2 = 53%, and with reduction of cardiovascular death compared to controls: RR 0.64; 95% CI 0.44-0.94; p = 0.02; I2 = 54%. There was a non-statistically significant reduction in myocardial infarction compared to control: RR 0.82, 95% CI 0.60-1.12; p = 0.57; I2 = 0%. Conclusion: In this meta-analysis of six randomized controlled clinical trials, IV was associated with a 33% and 36% relative risk reduction of all-cause mortality and cardiovascular death, respectively, in patients with CVD. We sought to promote consensus about the persistent benefits of influenza vaccination in patients with CVD by including two new clinical trials in CAD and HF, confirming the association of vaccination with risk reduction in subjects with CVD.

Influenza vaccines: an introduction

Seasonal influenza is a leading cause of severe respiratory infections and deaths. During an influenza infection, the immune system produces inflammatory mediators, which are largely responsible for the systemic symptoms and complications. Vaccines remain the most effective way to prevent influenza-related respiratory disease and non-respiratory complications despite antivirals. Numerous studies support the benefits of influenza vaccination, especially in high-risk groups. However, the effectiveness of the influenza vaccine varies markedly depending on the match between the circulating strains and those in the vaccine, and the recipient’s characteristics. Influenza vaccines are, in general, well-tolerated. Research could lead to more effective and, potentially, universal influenza vaccines.

Influenza vaccines: an introduction

Seasonal influenza is a leading cause of severe respiratory infections and deaths. Type A influenza can cause severe respiratory disease, death and pandemics. Influenza B accounts for about a quarter of the annual number of seasonal flu cases, but does not cause pandemics. Influenza C viruses cause mild symptoms in humans. Evidence suggests Influenza D does not cause disease in humans. During an influenza infection, the immune system produces inflammatory mediators, which are largely responsible for the systemic symptoms and complications. Vaccines remain the most effective way to prevent influenza-related respiratory disease and non-respiratory complications despite antivirals. Numerous studies support the benefits of influenza vaccination, especially in high-risk groups. However, the effectiveness of the influenza vaccine varies markedly depending on the match between the circulating strains and those in the vaccine, and the recipient's characteristics. Influenza vaccines are, in general, well-tolerated. Research could lead to more effective and, potentially, universal influenza vaccines.

Guillain-Barré syndrome following influenza vaccination: A 15-year nationwide population-based case-control study.

Influenza vaccination may increase the risk of developing Guillain-Barré syndrome (GBS) due to an elicited immune response, but the exact magnitude and duration of risk is unclear and hence the aim of this study. We conducted a retrospective nationwide population-based case-control study of prospectively collected data on all patients with first-time hospital-diagnosed GBS in Denmark between 2002 and 2016 and 10 age-, sex- and index date-matched population controls per case. The primary exposure was incident influenza vaccination 1 month prior to admission with GBS. We used medical registries to ascertain a complete hospital contact history of pre-existing morbidities. To examine duration of GBS risk, we repeated the analysis for five consecutive 1-month risk periods following vaccination. Of the 1295 GBS cases and 12,814 controls, 20 cases (1.5%) and 119 controls (0.9%) had received an influenza vaccination within the last month, yielding a comorbidity-adjusted odds ratio of 1.9 (95% confidence interval 1.1-3.2) for GBS. Stratified analyses by calendar time, gender and age showed similar results. The increased risk of GBS was largely confined to 1 month following influenza vaccination. The population-attributable fraction of GBS from influenza vaccination in Denmark was 0.4%. Influenza vaccination was associated with a slightly elevated risk of GBS occurrence within 1 month after vaccination. However, only 1.5% of GBS cases in Denmark are associated with recent influenza vaccination. Thus, the benefit of influenza vaccines in preventing influenza infections and associated morbidity and mortality needs to be weighed against the small absolute risk of GBS.

Influenza Viruses and Vaccines: The Role of Vaccine Effectiveness Studies for Evaluation of the Benefits of Influenza Vaccines.

Influenza is a vaccine preventable disease and vaccination remains the most effective method of controlling the morbidity and mortality of seasonal influenza, especially with respect to risk groups. To date, three types of influenza vaccines have been licensed: inactivated, live-attenuated, and recombinant haemagglutinin vaccines. Effectiveness studies allow an assessment of the positive effects of influenza vaccines in the field. The effectiveness of current influenza is suboptimal, being estimated as 40% to 60% when the vaccines strains are antigenically well-matched with the circulating viruses. This review focuses on influenza viruses and vaccines and the role of vaccine effectiveness studies for evaluating the benefits of influenza vaccines. Overall, influenza vaccines are effective against morbidity and mortality in all age and risk groups, especially in young children and older adults. However, the effectiveness is dependent on several factors such as the age of vaccinees, the match between the strain included in the vaccine composition and the circulating virus, egg-adaptations occurring during the production process, and the subject’s history of previous vaccination.

Association of Influenza Vaccination With Cardiovascular Risk

Influenza infection is associated with increased cardiovascular hospitalization and mortality. Our prior systematic review and meta-analysis hypothesized that influenza vaccination was associated with a lower risk of cardiovascular events. To evaluate, via an updated meta-analysis, if seasonal influenza vaccination is associated with a lower risk of fatal and nonfatal cardiovascular events and assess whether the newest cardiovascular outcome trial results are consistent with prior findings. A previously published meta-analysis of randomized controlled trials (RCTs) and a large 2021 cardiovascular outcome trial. Studies with RCTs published between 2000 and 2021 that randomized participants to either influenza vaccine or placebo/control. Eligible participants were inpatients and outpatients recruited for international multicenter RCTs and randomized to receive either influenza vaccine or placebo/control. PRISMA guidelines were followed in the extraction of study details, and risk of bias was assessed using the Cochrane Collaboration tool. Trial quality was evaluated using Cochrane criteria. Data were analyzed January 2020 and December 2021. Random-effects Mantel-Haenszel risk ratios (RRs) and 95% CIs were derived for a composite of major adverse cardiovascular events and cardiovascular mortality within 12 months of follow-up. Where available, analyses were stratified by patients with and without recent acute coronary syndrome (ACS) within 1 year of randomization. Six published RCTs comprising a total of 9001 patients were included (mean age, 65.5 years; 42.5% women; 52.3% with a cardiac history). Overall, influenza vaccine was associated with a lower risk of composite cardiovascular events (3.6% vs 5.4%; RR, 0.66; 95% CI, 0.53-0.83; P < .001). A treatment interaction was detected between patients with recent ACS (RR, 0.55; 95% CI, 0.41-0.75) and without recent ACS (RR, 1.00; 95% CI, 0.68-1.47) (P for interaction = .02). For cardiovascular mortality, a treatment interaction was also detected between patients with recent ACS (RR, 0.44; 95% CI, 0.23-0.85) and without recent ACS (RR, 1.45; 95% CI, 0.84-2.50) (P for interaction = .006), while 1.7% of vaccine recipients died of cardiovascular causes compared with 2.5% of placebo or control recipients (RR, 0.74; 95% CI, 0.42-1.30; P = .29). In this study, receipt of influenza vaccination was associated with a 34% lower risk of major adverse cardiovascular events, and individuals with recent ACS had a 45% lower risk. Given influenza poses a threat to population health during the COVID-19 pandemic, it is integral to counsel high-risk patients on the cardiovascular benefits of influenza vaccination.

Determinants of maternal influenza vaccination in the context of low- and middle-income countries: A systematic review.

Pregnancy and early infancy are considered to be the vulnerable phases for severe influenza infection causing morbidity and mortality. Despite WHO recommendations, influenza is not included in the immunization programs of many low- and middle-income countries. This systematic review is aimed at identifying barriers and facilitators for maternal influenza vaccination amongst the perinatal women and their health care providers in low- and middle-income countries. We selected 11 studies from the 1669 records identified from PubMed, CABI, EMBASE and Global Health databases. Studies related to both pandemic and routine influenza vaccination and studies conducted amongst women in the antenatal as well as postnatal period were included. Both qualitative, quantitative, cross-sectional and interventional studies were included. Knowledge about influenza disease, perception of the disease severity during pregnancy and risk to the foetus/newborn and perceived benefits of influenza vaccination during pregnancy were associated with increased uptake of influenza vaccination during pregnancy. Recommendation by health care provider, vaccination in previous pregnancy and availability of vaccine in public health system facilitated vaccine uptake. High parity, higher education, vaccination in the later months of pregnancy, less than 4 antenatal visits, concerns about vaccine safety and negative publicity in media were identified as barriers for influenza vaccination. Lack of government recommendation, concerns about safety and effectiveness and distrust in manufacturer were the barriers for the healthcare providers to recommend vaccination. While availability of influenza vaccine in public health system can be a key to the success of vaccine implementation program, increasing the awareness about need and benefits of maternal influenza vaccination amongst pregnant women as well as their health care providers is crucial to improve the acceptance of maternal influenza vaccination in low and middle-income countries.

The burden of influenza among Kenyan pregnant and postpartum women and their infants, 2015-2020.

BackgroundIn tropical Africa, data about influenza‐associated illness burden are needed to assess potential benefits of influenza vaccination among pregnant women. We estimated the incidence of influenza among pregnant women and their infants in Siaya County, Kenya.MethodsWe enrolled women at <31 weeks of gestation and conducted weekly follow‐up until 6‐month postpartum to identify acute respiratory illnesses (ARIs). We defined ARI among mothers as reported cough, rhinorrhoea or sore throat and among infants as maternal‐reported cough, difficulty breathing, rhinorrhoea or clinician diagnosis of respiratory illness. We collected nasal/nasopharyngeal and oropharyngeal swabs from mothers/infants with ARI and tested for influenza A and B using molecular assays. We calculated antenatal incidence of laboratory‐confirmed influenza among mothers and postnatal incidence among mothers and infants.ResultsDuring June 2015 to May 2020, we analysed data from 3,026 pregnant women at a median gestational age of 16 weeks (interquartile range [IQR], 13, 18) and followed 2,550 infants. Incidence of laboratory‐confirmed influenza during pregnancy (10.3 episodes per 1,000 person‐months [95% confidence interval {CI} 8.6–11.8]) was twofold higher than in the postpartum period (4.0 [95% CI 2.6–5.5]; p < 0.01). Incidence was significantly higher among human immunodeficiency virus (HIV)‐infected pregnant women (15.6 [95% CI 11.0–20.6] vs. 9.1 [95% CI 7.5–10.8]; p < 0.01). Incidence among young infants was 4.4 (95% CI 3.0–5.9) and similar among HIV‐exposed and HIV‐unexposed infants.ConclusionOur findings suggest a substantial burden of influenza illnesses during pregnancy, with a higher burden among HIV‐infected mothers. Kenyan authorities should consider the value of vaccinating pregnant women, especially if HIV infected.

Seasonal influenza vaccination of healthcare workers: a narrative review.

Influenza is an acute respiratory disease caused by the influenza virus which often occurs in outbreaks and epidemics worldwide. The World Health Organization recommends annual vaccination of healthcare workers (HCWs) against influenza, because most of them are involved in the direct care of patients with a high risk of influenza-related complications. Given the significance of the disease burden, a targeted literature review was conducted to assess issues related to influenza vaccination among HCWs. The primary aim of this review was to assess the incidence of influenza among medical personnel and healthcare-associated influenza, and to outline the benefits of influenza vaccination for patients and HCWs themselves. Vaccination of HCWs seems to be an important strategy for reducing the transmission of influenza from healthcare personnel to their patients and, therefore, for reducing patient morbidity and mortality, increasing patient safety, and reducing work absenteeism among HCWs. The benefits of influenza vaccination for their patients and for HCWs themselves are addressed in literature, but the evidence is mixed and often of low-quality. Int J Occup Med Environ Health. 2022;35(2):127-39.

Induction of trained immunity by influenza vaccination - impact on COVID-19.

Non-specific protective effects of certain vaccines have been reported, and long-term boosting of innate immunity, termed trained immunity, has been proposed as one of the mechanisms mediating these effects. Several epidemiological studies suggested cross-protection between influenza vaccination and COVID-19. In a large academic Dutch hospital, we found that SARS-CoV-2 infection was less common among employees who had received a previous influenza vaccination: relative risk reductions of 37% and 49% were observed following influenza vaccination during the first and second COVID-19 waves, respectively. The quadrivalent inactivated influenza vaccine induced a trained immunity program that boosted innate immune responses against various viral stimuli and fine-tuned the anti-SARS-CoV-2 response, which may result in better protection against COVID-19. Influenza vaccination led to transcriptional reprogramming of monocytes and reduced systemic inflammation. These epidemiological and immunological data argue for potential benefits of influenza vaccination against COVID-19, and future randomized trials are warranted to test this possibility.

Determinants of healthcare workers’ willingness to receive the influenza vaccine in Tunisia

Abstract Background Influenza is a contagious respiratory disease that may lead to severe illness. Given their frequent contact with ill individuals, healthcare workers (HCWs) are at elevated risk of developing influenza and of transmitting the disease to their patients. We aimed in this study to assess flu vaccination intention among Tunisian HCWs and to identify its determinants. Methods A cross sectional study was conducted among Tunisian HCWs with direct patient contact during the 2018-2019 influenza season. Participants were recruited in primary and secondary healthcare facilities according to a self-weighted multistage sampling. Factors associated with influenza vaccination intention were assessed using a multivariate logistic regression analysis. Results In this study, 1231 HCWs were enrolled with a mean age of 44.5±9.3 years and a sex ratio equal to 0.25. Among respondents, 43.1% (95% CI: [40.0-45.8]) declared their willingness to receive the IV if recommended for HCWs and provided for free. Participants who received the IV during the 2018-2019 influenza season ((ORa=34.42 [16.41-72.21]), who knew that IV is indicated annually for HCWs (ORa=1.66 [1.21-2.30]), who had high confidence regarding IV efficacy (ORa=1.99 [1.48-2.68]), who believed that IV should be mandatory for HCWs (ORa=2,36 [1.76-3.18]) and that HCWs' vaccination against influenza is important in order to protect patients (ORa=1.92 [1.37-2.69]) were more likely to be willing to receive the IV. However, nurses were less likely to be willing to receive the vaccine than physicians (ORa=0.66 [0.44-0.98]). Conclusions Less than half of participants reported their willingness to receive the IV. Our results suggest that flu vaccination acceptance is associated with higher IV uptake and with favorable attitudes regarding influenza vaccination. This highlights the need to implement regular flu awareness campaigns in healthcare facilities aiming to encourage vaccination among HCWs. Key messages Majority of healthcare workers reported their unwillingness to receive the influenza vaccine. Educating health personnel about the benefits of influenza vaccination to themselves and their patients is necessary.