Clinical and socioeconomic impact of seasonal and pandemic influenza in adults and the elderly

Hospital admissions for pyoderma gangrenosum in Spain (1999-2021): Epidemiological and clinical characteristics, temporal trends, and factors associated with poor prognosis and higher cost

Background and Aims

Pyoderma gangrenosum (PG) is a neutrophilic inflammatory dermatosis that can be idiopathic or associated with other diseases. The aim was to analyze the epidemiological and clinical characteristics, temporal trends, risk factors for poor prognosis, and admission costs associated with PG in Spain.

Methods

We conducted a retrospective study, based on the Hospital Discharge Registry of the Spanish National Health System in Spain from 1999 to 2021.

Results

Of 82,161,670 admissions during the study period, 4901 were for PG (hospitalization rate of 59.7/1,000,000 admissions). PG hospitalizations increased from 28.8/1,00,000 in 1999 to 91.9/1,000,000 in 2021. PG was a primary cause of admission in 60.5% of cases, and 58.4% of patients were women. The main PG-related comorbidities were inflammatory bowel disease (15.7%) and neoplasms (10%). There was a significant increase over the years in admissions for inflammatory bowel disease, monoclonal gammopathy of undetermined significance, and lymphoma, as well as an increase in diseases unrelated to PG, such as hypertension, diabetes, and chronic kidney disease. The hospital mortality rate was 5.6%. Death was associated with PG being a primary diagnosis, older age, leukemia, neoplasms, diabetes, and chronic kidney disease. The cost of treatment increased over the years and was higher in older people.

Conclusion

PG cases in the inpatient setting in Spain over the past 23 years make up a tiny proportion of all hospital admissions, although the rate of hospitalization for PG has increased in the last two decades.

Phytochemicals in Drug Discovery-A Confluence of Tradition and Innovation

Phytochemicals have a long and successful history in drug discovery. With recent advancements in analytical techniques and methodologies, discovering bioactive leads from natural compounds has become easier. Computational techniques like molecular docking, QSAR modelling and machine learning, and network pharmacology are among the most promising new tools that allow researchers to make predictions concerning natural products' potential targets, thereby guiding experimental validation efforts. Additionally, approaches like LC-MS or LC-NMR speed up compound identification by streamlining analytical processes. Integrating structural and computational biology aids in lead identification, thus providing invaluable information to understand how phytochemicals interact with potential targets in the body. An emerging computational approach is machine learning involving QSAR modelling and deep neural networks that interrelate phytochemical properties with diverse physiological activities such as antimicrobial or anticancer effects.

Vaccine delivery systems and administration routes: Advanced biotechnological techniques to improve the immunization efficacy

Since the first use of vaccine tell the last COVID-19 pandemic caused by spread of SARS-CoV-2 worldwide, the use of advanced biotechnological techniques has accelerated the development of different types and methods for immunization. The last pandemic showed that the nucleic acid-based vaccine, especially mRNA, has an advantage in terms of development time; however, it showed a very critical drawback namely, the higher costs when compared to other strategies, and its inability to protect against new variants. This showed the need of more improvement to reach a better delivery and efficacy. In this review we will describe different vaccine delivery systems including, the most used viral vector, and also variable strategies for delivering of nucleic acid-based vaccines especially lipid-based nanoparticles formulation, polymersomes, electroporation and also the new powerful tools for the delivery of mRNA, which is based on the use of cell-penetrating peptides (CPPs). Additionally, we will also discuss the main challenges associated with each system. Finlay, the efficacy and safety of the vaccines depends not only on the formulations and delivery systems, but also the dosage and route of administration are also important players, therefore we will see the different routes for the vaccine administration including traditionally routes (intramuscular, Transdermal, subcutaneous), oral inhalation or via nasal mucosa, and will describe the advantages and disadvantage of each administration route.

Postpandemic Sentinel Surveillance of Respiratory Diseases in the Context of the World Health Organization Mosaic Framework: Protocol for a Development and Evaluation Study Involving the English Primary Care Network 2023-2024

BACKGROUND

Prepandemic sentinel surveillance focused on improved management of winter pressures, with influenza-like illness (ILI) being the key clinical indicator. The World Health Organization (WHO) global standards for influenza surveillance include monitoring acute respiratory infection (ARI) and ILI. The WHO's mosaic framework recommends that the surveillance strategies of countries include the virological monitoring of respiratory viruses with pandemic potential such as influenza. The Oxford-Royal College of General Practitioner Research and Surveillance Centre (RSC) in collaboration with the UK Health Security Agency (UKHSA) has provided sentinel surveillance since 1967, including virology since 1993.

OBJECTIVE

We aim to describe the RSC's plans for sentinel surveillance in the 2023-2024 season and evaluate these plans against the WHO mosaic framework.

METHODS

Our approach, which includes patient and public involvement, contributes to surveillance objectives across all 3 domains of the mosaic framework. We will generate an ARI phenotype to enable reporting of this indicator in addition to ILI. These data will support UKHSA's sentinel surveillance, including vaccine effectiveness and burden of disease studies. The panel of virology tests analyzed in UKHSA's reference laboratory will remain unchanged, with additional plans for point-of-care testing, pneumococcus testing, and asymptomatic screening. Our sampling framework for serological surveillance will provide greater representativeness and more samples from younger people. We will create a biomedical resource that enables linkage between clinical data held in the RSC and virology data, including sequencing data, held by the UKHSA. We describe the governance framework for the RSC.

RESULTS

We are co-designing our communication about data sharing and sampling, contextualized by the mosaic framework, with national and general practice patient and public involvement groups. We present our ARI digital phenotype and the key data RSC network members are requested to include in computerized medical records. We will share data with the UKHSA to report vaccine effectiveness for COVID-19 and influenza, assess the disease burden of respiratory syncytial virus, and perform syndromic surveillance. Virological surveillance will include COVID-19, influenza, respiratory syncytial virus, and other common respiratory viruses. We plan to pilot point-of-care testing for group A streptococcus, urine tests for pneumococcus, and asymptomatic testing. We will integrate test requests and results with the laboratory-computerized medical record system. A biomedical resource will enable research linking clinical data to virology data. The legal basis for the RSC's pseudonymized data extract is The Health Service (Control of Patient Information) Regulations 2002, and all nonsurveillance uses require research ethics approval.

CONCLUSIONS

The RSC extended its surveillance activities to meet more but not all of the mosaic framework's objectives. We have introduced an ARI indicator. We seek to expand our surveillance scope and could do more around transmissibility and the benefits and risks of nonvaccine therapies.

Impact of influenza related hospitalization in Spain: characteristics and risk factor of mortality during five influenza seasons (2016 to 2021)

Background

Estimating the global influenza burden in terms of hospitalization and death is important for optimizing prevention policies. Identifying risk factors for mortality allows for the design of strategies tailored to groups at the highest risk. This study aims to (a) describe the clinical characteristics of hospitalizations with a diagnosis of influenza over five flu seasons (2016-2017 to 2020-2021), (b) assess the associated morbidity (hospitalization rates and ICU admissions rate), mortality and cost of influenza hospitalizations in different age groups and (c) analyze the risk factors for mortality.

Methods

This retrospective study included all hospital admissions with a diagnosis of influenza in Spain for five influenza seasons. Data were extracted from the Spanish National Surveillance System for Hospital Data from 1 July 2016 to 30 June 2021. We identified cases coded as having influenza as a primary or secondary diagnosis (International Classification of Diseases, 10th revision, J09-J11). The hospitalization rate was calculated relative to the general population. Independent predictors of mortality were identified using multivariable logistic regression.

Results

Over the five seasons, there were 127,160 hospitalizations with a diagnosis of influenza. The mean influenza hospitalization rate varied from 5/100,000 in 2020-2021 (COVID-19 pandemic) to 92.9/100,000 in 2017-2018. The proportion of influenza hospitalizations with ICU admission was 7.4% and was highest in people aged 40-59 years (13.9%). The case fatality rate was 5.8% overall and 9.4% in those aged 80 years or older. Median length of stay was 5 days (and 6 days in the oldest age group). In the multivariable analysis, independent risk factors for mortality were male sex (odds ratio [OR] 1.14, 95% confidence interval [95% CI] 1.08-1.20), age (<5 years: OR 1; 5-19 years: OR 2.02, 95%CI 1.17-3.49; 20-39 years: OR 4.11, 95% CI 2.67-6.32; 40-59 years: OR 8.15, 95% CI 5.60-11.87; 60-79 years: OR 15.10, 95% CI 10.44-21.84; ≥80 years: OR 33.41, 95% CI 23.10-48.34), neurological disorder (OR 1.97, 95% CI 1.83-2.11), heart failure (OR 1.85, 95% CI 1.74-1.96), chronic kidney disease (OR 1.33, 95% CI 1.25-1.41), chronic liver disease (OR 2.95, 95% CI 2.68-3.27), cancer (OR 1.85, 95% CI 1.48-2.24), coinfection with SARS-CoV2 (OR 3.17, 95% CI 2.34-4.28), influenza pneumonia (OR 1.76, 95% CI 1.66-1.86) and admission to intensive care (OR 7.81, 95% CI 7.31-8.36).

Conclusion

Influenza entails a major public health burden. People aged over 60-and especially those over 80-show the longest hospital stays. Age is also the most significant risk factor for mortality, along with certain associated comorbidities.

Predictors of severity and prolonged hospital stay of viral acute respiratory infections (ARI) among children under five years in Burkina Faso, 2016-2019

BACKGROUND

Viruses are the leading etiology of acute respiratory infections (ARI) in children. However, there is limited knowledge on drivers of severe acute respiratory infection (SARI) cases involving viruses. We aimed to identify factors associated with severity and prolonged hospitalization of viral SARI among children < 5 years in Burkina Faso.

METHODS

Data were collected from four SARI sentinel surveillance sites during October 2016 through April 2019. A SARI case was a child < 5 years with an acute respiratory infection with history of fever or measured fever ≥ 38 °C and cough with onset within the last ten days, requiring hospitalization. Very severe ARI cases required intensive care or had at least one danger sign. Oropharyngeal/nasopharyngeal specimens were collected and analyzed by multiplex real-time reverse-transcription polymerase chain reaction (rRT-PCR) using FTD-33 Kit. For this analysis, we included only SARI cases with rRT-PCR positive test results for at least one respiratory virus. We used simple and multilevel logistic regression models to assess factors associated with very severe viral ARI and viral SARI with prolonged hospitalization.

RESULTS

Overall, 1159 viral SARI cases were included in the analysis after excluding exclusively bacterial SARI cases (n = 273)very severe viral ARI cases were common among children living in urban areas (AdjOR = 1.3; 95% CI: 1.1-1.6), those < 3 months old (AdjOR = 1.5; 95% CI: 1.1-2.3), and those coinfected with Klebsiella pneumoniae (AdjOR = 1.9; 95% CI: 1.2-2.2). Malnutrition (AdjOR = 2.2; 95% CI: 1.1-4.2), hospitalization during the rainy season (AdjOR = 1.71; 95% CI: 1.2-2.5), and infection with human CoronavirusOC43 (AdjOR = 3; 95% CI: 1.2-8) were significantly associated with prolonged length of hospital stay (> 7 days).

CONCLUSION

Younger age, malnutrition, codetection of Klebsiella pneumoniae, and illness during the rainy season were associated with very severe cases and prolonged hospitalization of SARI involving viruses in children under five years. These findings emphasize the need for preventive actions targeting these factors in young children.

Terpenes and cannabidiol against human corona and influenza viruses-Anti-inflammatory and antiviral in vitro evaluation

The activity of the terpenes and Cannabidiol (CBD) against human coronavirus (HCoV) strain OC43 and influenza A (H1N1) was evaluated in human lung fibroblasts (MRC-5 cells). Also, we examined whether these ingredients inhibit pro-inflammatory cytokines in peripheral blood mononuclear cells (PBMC). The tested preparations exhibited both anti-inflammatory and antiviral effects. The combination of terpenes was effective against both HCoV-OC43 and influenza A (H1N1) virus. The addition of CBD improved the antiviral activity in some, but not all cases. This variation in activity may suggest an antiviral mechanism. In addition, there was a strong correlation between the quantitative results from a cell-viability assay and the cytopathic effect after 72 h, as observed under a microscope. The anti-inflammatory properties of terpenes were demonstrated using a pro-inflammatory cytokine-inhibition assay, which revealed significant cytokine inhibition and enhanced by the addition of CBD.

Exploration of phytochemical compounds against Marburg virus using QSAR, molecular dynamics, and free energy landscape

Marburg virus disease (MVD) is caused by the Marburg virus, a one-of-a-kind zoonotic RNA virus from the genus Filovirus. Thus, this current study employed AI-based QSAR and molecular docking-based virtual screening for identifying potential binders against the target protein (nucleoprotein (NP)) of the Marburg virus. A total of 2727 phytochemicals were used for screening, out of which the top three compounds (74977521, 90470472, and 11953909) were identified based on their predicted bioactivity (pIC50) and binding score (< - 7.4 kcal/mol). Later, MD simulation in triplicates and trajectory analysis were performed which showed that 11953909 and 74977521 had the most stable and consistent complex formations and had the most significant interactions with the highest number of hydrogen bonds. PCA (principal component analysis) and FEL (free energy landscape) analysis indicated that these compounds had favourable energy states for most of the conformations. The total binding free energy of the compounds using the MM/GBSA technique showed that 11953909 (ΔGTOTAL = - 30.78 kcal/mol) and 74977521 (ΔGTOTAL = - 30 kcal/mol) had the highest binding affinity with the protein. Overall, this in silico pipeline proposed that the phytochemicals 11953909 and 74977521 could be the possible binders of NP. This study aimed to find phytochemicals inhibiting the protein's function and potentially treating MVD.

Lessons learned from the COVID-19 pandemic for improved influenza control

The World Health Organization noted that COVID-19 vaccination programmes could be leveraged to deliver influenza vaccination. In 2008, the International Federation of Pharmaceutical Manufacturers and Associations' (IFPMA) Influenza Vaccine Supply International Task Force (IVS) developed a survey method using the number of influenza vaccine doses distributed globally to estimate vaccination coverage rates. Seven hundred and ninety-seven million doses were distributed in 2021, representing a 205% increase over the 262 million doses distributed in 2004, exceeding the number of doses distributed during and after the 2009-2010 influenza pandemic. The most obvious explanation for the global increase is the enabling of critical elements of the vaccine ecosystem by decision-makers during the COVID-19 pandemic to reinforce implementation of influenza vaccination programs. Most of the improvements in performance of influenza programs during the COVID-19 pandemic can be classified in four categories: 1) promoting vaccination using tailored approaches for specific populations; 2) improving convenient access to influenza vaccines in COVID-safe settings; 3) improving reimbursement of seasonal influenza vaccination for priority groups; 4) maintaining the timing of vaccination to the autumn. In spite of the increase in rates of seasonal influenza vaccines distributed during the COVID-19 pandemic, globally, the rate of influenza dose distribution is sub-optimal, and a considerable proportion of the influenza infections remains preventable. To sustain the benefits from increased uptake of influenza vaccines, governments need to sustain the efforts made during the COVID-19 pandemic, and a number of global policy endeavours should be undertaken, including developing a clear global roadmap for achieving influenza control objectives, adopted by a WHA resolution, in line with the strategic objective 3 of the Global Influenza Strategy 2030, embedded in the Immunization Agenda 2030 (IA2030).

Research progress of sophoridine's pharmacological activities and its molecular mechanism: an updated review

Background: Sophoridine, the major active constituent of Sophora alopecuroides and its roots, is a bioactive alkaloid with a wide range of pharmacological effects, including antitumor, anti-inflammatory, antiviral, antibacterial, analgesic, cardioprotective, and immunoprotective activities. Sophora flavescens Aiton is a traditional Chinese medicine that is bitter and cold. Additionally, it also exhibits the effects of clearing heat, eliminating dampness, and expelling insects. Aims of the study: To summarize the pharmacological research and associated mechanisms of sophoridine, we compiled this review by combining a huge body of relevant literature. Materials and methods: The information related to this article was systematically collected from the scientific literature databases including PubMed, Google Scholar, Web of Science, Science Direct, Springer, China National Knowledge Infrastructure, published books, PhD and MS dissertations. Results: Its antitumor activity is particularly remarkable, as it can inhibit cancer cell proliferation, invasion, and metastasis while inducing cell cycle arrest and apoptosis. Additionally, sophoridine also holds therapeutic potential for myocardial ischemia, osteoporosis, arrhythmias, and neurological disorders, primarily through the suppression of related inflammatory factors and cell apoptosis. However, sophoridine has also exhibited adverse effects such as hepatotoxicity and neurotoxicity. The antidisease effect and mechanism of sophoridine are diverse, so it has high research value. Conclusion: As an important traditional Chinese medicine alkaloid, modern pharmacological studies have demonstrated that sophoridine has prominent bioactivities, especially on anti-tumor anti-inflammation activities, and cardiovascular system protection. These activities provide prospects for novel drug development for cancer and some chronic diseases. Nevertheless, the understanding of the multitarget network pharmacology, long-term in vivo toxicity, and clinical efficacy of sophoridine require further detailed research.

Enhanced passive safety surveillance of the MF59-adjuvanted quadrivalent influenza vaccine in the elderly during the 2021/22 influenza season

In accordance with European directives, each year the enhanced safety surveillance (ESS) of seasonal influenza vaccines should be conducted in order to detect any potential increase in reactogenicity when the vaccine composition is updated or a new formulation becomes available. The objective of this passive ESS (EPSS) was to assess the frequency of spontaneously reported adverse events (AEs) following vaccination with the 2021/22 formulation of the MF59-adjuvanted quadrivalent influenza vaccine (aQIV) among older adults in Italy through the collection of data within a short time period (start of seasonal influenza vaccination) in order to monitor the reactogenicity of aQIV early in the season. All AEs reported within seven days following vaccination were analyzed by type and seriousness. In all, 1,059 vaccination cards were distributed to individuals aged ≥65 years. Only one, non-serious, spontaneous individual case safety report was submitted, yielding an overall rate of 0.9 per 1,000 doses administered. This report consisted of a reactogenic AE of pyrexia. The EPSS confirmed that the reactogenicity profile of aQIV was consistent with the known safety profile of the previous trivalent formulation. These optimal safety data could bolster public confidence in influenza vaccination and help to improve vaccination coverage.

Long Short-term Memory-Based Prediction of the Spread of Influenza-Like Illness Leveraging Surveillance, Weather, and Twitter Data: Model Development and Validation

BACKGROUND

The potential to harness the plurality of available data in real time along with advanced data analytics for the accurate prediction of influenza-like illness (ILI) outbreaks has gained significant scientific interest. Different methodologies based on the use of machine learning techniques and traditional and alternative data sources, such as ILI surveillance reports, weather reports, search engine queries, and social media, have been explored with the ultimate goal of being used in the development of electronic surveillance systems that could complement existing monitoring resources.

OBJECTIVE

The scope of this study was to investigate for the first time the combined use of ILI surveillance data, weather data, and Twitter data along with deep learning techniques toward the development of prediction models able to nowcast and forecast weekly ILI cases. By assessing the predictive power of both traditional and alternative data sources on the use case of ILI, this study aimed to provide a novel approach for corroborating evidence and enhancing accuracy and reliability in the surveillance of infectious diseases.

METHODS

The model's input space consisted of information related to weekly ILI surveillance, web-based social (eg, Twitter) behavior, and weather conditions. For the design and development of the model, relevant data corresponding to the period of 2010 to 2019 and focusing on the Greek population and weather were collected. Long short-term memory (LSTM) neural networks were leveraged to efficiently handle the sequential and nonlinear nature of the multitude of collected data. The 3 data categories were first used separately for training 3 LSTM-based primary models. Subsequently, different transfer learning (TL) approaches were explored with the aim of creating various feature spaces combining the features extracted from the corresponding primary models' LSTM layers for the latter to feed a dense layer.

RESULTS

The primary model that learned from weather data yielded better forecast accuracy (root mean square error [RMSE]=0.144; Pearson correlation coefficient [PCC]=0.801) than the model trained with ILI historical data (RMSE=0.159; PCC=0.794). The best performance was achieved by the TL-based model leveraging the combination of the 3 data categories (RMSE=0.128; PCC=0.822).

CONCLUSIONS

The superiority of the TL-based model, which considers Twitter data, weather data, and ILI surveillance data, reflects the potential of alternative public sources to enhance accurate and reliable prediction of ILI spread. Despite its focus on the use case of Greece, the proposed approach can be generalized to other locations, populations, and social media platforms to support the surveillance of infectious diseases with the ultimate goal of reinforcing preparedness for future epidemics.

Economic impact of acute respiratory disease pandemics: A scoping review

Background

The economic impact of acute respiratory disease pandemics has yet to be specifically systematically reviewed. The aim of this scoping review is to identify and classify the economic impacts and its values and ranges.

Materials and Methods

We conducted a literature search across three key databases using an extensive list of keywords. Then, we included studies which explored direct and indirect costs as well as broader economic impact associated with different nine acute respiratory diseases, i.e., pandemic and seasonal influenza, avian influenza, equine influenza, swine influenza, severe acute respiratory syndrome, coronavirus disease 2019, Middle East respiratory syndrome, H1N1, and H7N9.

Results

We included 62 studies in English language between 1987 and 2020, mostly from the countries of East Asia and Pacific pertinent. We classified the economic impact into 5 main categories and 18 subcategories. The main categories were macroeconomic impacts, impacts on health cost, industry, businesses and trade, and education.

Conclusion

Respiratory disease pandemics have widely impacted different sectors of economy such as the direct cost on macroeconomic, providing and receiving health services, disease management, industries, business and trade, education, and indirect costs due to productivity losses. However, lots of the reviewed studies were unable to quantify the actual economic cost of these impacts. This made it challenging to conduct any kind of quantitative comparison of the results. A key priority for future research is to develop standard methods to quantify the broader economic costs of respiratory disease pandemics. Understanding the total economic impact of respiratory disease pandemics is a key step to inform national and international priority setting for disease prevention and pandemic control interventions.

Infodemiology of RSV in Italy (2017-2022): An Alternative Option for the Surveillance of Incident Cases in Pediatric Age?

The aim of this study was to evaluate whether or not online queries for Respiratory Syncytial Virus (RSV) retrieved by means of Google Trends™ and the Italian Wikipedia analysis program mirror the occurrence of influenza-like illnesses (ILI), as reported by the Italian Influenza Surveillance network (InfluNet). Estimated rates for ILI in the general population and in the age groups 0−4 years and 5−14 years were obtained for the influenza seasons 2017−2018 to 2020−2021. Similarly, a weekly fraction of online searches was retrieved for a series of terms associated with Respiratory Syncytial Virus. Next, trends for daily visualization of Italian Wikipedia Pages for Human Respiratory Syncytial Virus, Pneumonia, Bronchiolitis, Influenza, and Respiratory Failure were similarly retrieved. The correlation of all search terms with ILI was analyzed by means of Spearman’s rank correlation analysis. Among search terms associated with the clinical diagnosis of Respiratory Syncytial Virus infections, the occurrence of ILI was highly correlated only with Bronchiolitis in the age group 0−4 years (β 0.210, p = 0.028), while more generic search terms, such as Bronchitis, fever, influenza, and Pneumonia, were identified as effective predictors of ILI, in general and by age groups. In a regression analysis modeled with ILIs as the outcome variable, daily visualizations for the Wikipedia pages on Bronchiolitis were identified as negative predictors for ILI in general (β = −0.152, p = 0.032), ILI in age group 0−4 years (β = −0.264, p = 0.001) and 5−14 years (β = −0.202, p = 0.006), while Influenza was characterized as a positive effector for ILIs in the age group 5−14 years (β = 0.245, p = 0.001). Interestingly, not only were the search terms extensively correlated with one another, but all of them were also characterized by autocorrelation through a Durbin-Watson test (all estimates DW < 2.0) In summary, our study identified a complicated pattern of data visualization as no clear association between rates of ILI in pediatric age group 0−4 and 5 to 14 years was actually found. Finally, our data stress that the infodemiology option may be quite problematic for assessing the time trend of RSV infections in Italy until more appropriate reporting will be made available, by sharing estimates of Lower Respiratory Tract Infections, and through a more accurate characterization of younger age groups.

Antiviral Potential of Natural Resources against Influenza Virus Infections

Influenza is a severe contagious disease caused by influenza A and B viruses. The WHO estimates that annual outbreaks lead to 3-5 million severe infections of which approximately 10% lead to the death of the patient. While vaccination is the cornerstone of prevention, antiviral drugs represent the most important treatment option of acute infections. Only two classes of drugs are currently approved for the treatment of influenza in numerous countries: M2 channel blockers and neuraminidase inhibitors. In some countries, additional compounds such as the recently developed cap-dependent endonuclease inhibitor baloxavir marboxil or the polymerase inhibitor favipiravir are available. However, many of these compounds suffer from poor efficacy, if not applied early after infection. Furthermore, many influenza strains have developed resistances and lost susceptibility to these compounds. As a result, there is an urgent need to develop new anti-influenza drugs against a broad spectrum of subtypes. Natural products have made an important contribution to the development of new lead structures, particularly in the field of infectious diseases. Therefore, this article aims to review the research on the identification of novel lead structures isolated from natural resources suitable to treat influenza infections.

Identification of Critical Genes and Pathways for Influenza A Virus Infections via Bioinformatics Analysis

Influenza A virus (IAV) requires the host cellular machinery for many aspects of its life cycle. Knowledge of these host cell requirements not only reveals molecular pathways exploited by the virus or triggered by the immune system but also provides further targets for antiviral drug development. To uncover critical pathways and potential targets of influenza infection, we assembled a large amount of data from 8 RNA sequencing studies of IAV infection for integrative network analysis. Weighted gene co-expression network analysis (WGCNA) was performed to investigate modules and genes correlated with the time course of infection and/or multiplicity of infection (MOI). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to explore the biological functions and pathways of the genes in 5 significant modules. Top hub genes were identified using the cytoHubba plugin in the protein interaction network. The correlation between expression levels of 7 top hub genes and time course or MOI was displayed and validated, including BCL2L13, PLSCR1, ARID5A, LMO2, NDRG4, HAP1, and CARD10. Dysregulated expression of these genes potently impacted the development of IAV infection through modulating IAV-related biological processes and pathways. This study provides further insights into the underlying molecular mechanisms and potential targets in IAV infection.

Interpretation of Discrepancies between Cities in the Transmission of COVID-19: Evidence from China in the First Weeks of the Pandemic: Interpreting the Discrepancies of COVID-19 Transmission

OBJECTIVES

This study aims to examine and explain the differences at city level in cumulative Covid-19 cases and time from first to last infection, during the first six weeks of the epidemic in China.

METHODS

A quantitative study is conducted in China based on the multi-source spatial data of 315 Chinese cities. Firstly, the spatial discrepancy of COVID-19 transmission was examined based on spatial autocorrelation analysis and hot pot analysis. Next, a comprehensive indicator framework was established by including a wide range of factors such as human mobility, geographical features, public health measures and residents' awareness. Finally, multivariate regression models employing the variables were constructed to identify the determinants of Covid-19 transmission.

RESULTS

Significant spatial discrepancy of transmission was proved and ten determinants were identified.

CONCLUSIONS

The transmission consequence (measured by number of cumulative cases) was mostly correlated with the migration scale from Wuhan, followed by socio-economic factors. Transmission duration (measured by the time from the first to last case within the city) was mostly determined by total migration scale and lockdown speed, which suggests that timely implementation of public health measures facilitated fast control of transmission. Residents' attention to COVID-19 was proved to be not only helpful for reducing confirmed cases, but also in favor of rapid transmission control. Altitude produced slightly but significant effect on transmission duration. Those conclusions are expected to provide decision support for the local governments of China and other jurisdictions.

Burden of severe illness associated with laboratory confirmed influenza in adults aged 50-64 years: A rapid review

BACKGROUND

While the high burden of illness caused by seasonal influenza in children and the elderly is well recognize, less is known about the burden in adults 50-64 years of age. The lack of data for this age group is a key challenge in evaluating the cost-effectiveness of immunization programs. We aimed to assess influenza-associated hospitalization and mortality rates and case fatality rates for hospitalized cases among adults aged 50-64 years.

METHODS

This rapid review was conducted according to the PRISMA; we searched MEDLINE, EMBASE, Cochrane, Web of Science, and grey literature for articles and reports published since 2010. Studies reporting rates of hospitalization and/or mortality associated with laboratory-confirmed influenza among adults 50-64 or 45-64 years of age for the 2010-11 through 2019-20 seasons were included.

RESULTS

Twenty studies from 13 countries were reviewed. Reported rates of hospitalization associated with laboratory-confirmed influenza were 5.7 to 112.8 per 100,000. Rates tended to be higher in the 2015-2019 compared with the 2010-2014 seasons and were higher in studies reporting data from high-income versus low and middle-income countries. Mortality rates were reported in only one study, with rates ranging from 0.8 to 3.5 per 100,000 in four different seasons. The case fatality rate among those hospitalized with influenza, as reported by population-based studies, ranged from 1.3% to 5.6%.

CONCLUSIONS

Seasonal influenza imposes a significant burden of morbidity on adults 50-64 years of age but with high heterogeneity across seasons and geographic regions. Ongoing surveillance is required to improve estimates of burden to better inform influenza vaccination and other public health policies.

Antiviral plant-derived natural products to combat RNA viruses: Targets throughout the viral life cycle

There is a need for new effective antivirals, particularly in response to the development of antiviral drug resistance and emerging RNA viruses such as SARS‐CoV‐2. Plants are a significant source of structurally diverse bioactive compounds for drug discovery suggesting that plant‐derived natural products could be developed as antiviral agents. This article reviews the antiviral activity of plant‐derived natural products against RNA viruses, with a focus on compounds targeting specific stages of the viral life cycle. A range of plant extracts and compounds have been identified with antiviral activity, often against multiple virus families suggesting they may be useful as broad‐spectrum antiviral agents. The antiviral mechanism of action of many of these phytochemicals is not fully understood and there are limited studies and clinical trials demonstrating their efficacy and toxicity in vivo. Further research is needed to evaluate the therapeutic potential of plant‐derived natural products as antiviral agents.

Nanovaccine Delivery Approaches and Advanced Delivery Systems for the Prevention of Viral Infections: From Development to Clinical Application

Viral infections causing pandemics and chronic diseases are the main culprits implicated in devastating global clinical and socioeconomic impacts, as clearly manifested during the current COVID-19 pandemic. Immunoprophylaxis via mass immunisation with vaccines has been shown to be an efficient strategy to control such viral infections, with the successful and recently accelerated development of different types of vaccines, thanks to the advanced biotechnological techniques involved in the upstream and downstream processing of these products. However, there is still much work to be done for the improvement of efficacy and safety when it comes to the choice of delivery systems, formulations, dosage form and route of administration, which are not only crucial for immunisation effectiveness, but also for vaccine stability, dose frequency, patient convenience and logistics for mass immunisation. In this review, we discuss the main vaccine delivery systems and associated challenges, as well as the recent success in developing nanomaterials-based and advanced delivery systems to tackle these challenges. Manufacturing and regulatory requirements for the development of these systems for successful clinical and marketing authorisation were also considered. Here, we comprehensively review nanovaccines from development to clinical application, which will be relevant to vaccine developers, regulators, and clinicians.

Rational design of a deuterium-containing M2-S31N channel blocker UAWJ280 with in vivo antiviral efficacy against both oseltamivir sensitive and -resistant influenza A viruses

Seasonal influenza A virus (IAV) infections are among the most important global health problems. FDA-approved antiviral therapies against IAV include neuraminidase inhibitors, M2 inhibitors, and polymerase inhibitor baloxavir. Resistance against adamantanes (amantadine and rimantadine) is widespread as virtually all IAV strains currently circulating in the human population are resistant to adamantanes through the acquisition of the S31N mutation. The neuraminidase inhibitor-resistant strains also contain the M2-S31N mutant, suggesting M2-S31N is a high-profile antiviral drug target. Here we report the development of a novel deuterium-containing M2-S31N inhibitor UAWJ280. UAWJ280 had broad-spectrum antiviral activity against both oseltamivir sensitive and -resistant influenza A strains and had a synergistic antiviral effect in combination with oseltamivir in cell culture. In vivo pharmacokinetic (PK) studies demonstrated that UAWJ280 had favourable PK properties. The in vivo mouse model study showed that UAWJ280 was effective alone or in combination with oseltamivir in improving clinical signs and survival after lethal challenge with an oseltamivir sensitive IAV H1N1 strain. Furthermore, UAWJ280 was also able to ameliorate clinical signs and increase survival when mice were challenged with an oseltamivir-resistant IAV H1N1 strain. In conclusion, we show for the first time that the M2-S31N channel blocker UAWJ280 has in vivo antiviral efficacy in mice that are infected with either oseltamivir sensitive or -resistant IAVs, and it has a synergistic antiviral effect with oseltamivir.

Screening of Potent Phytochemical Inhibitors Against SARS-CoV-2 Main Protease: An Integrative Computational Approach

Coronavirus disease 2019 (COVID-19) is a potentially lethal and devastating disease that has quickly become a public health threat worldwide. Due to its high transmission rate, many countries were forced to implement lockdown protocols, wreaking havoc on the global economy and the medical crisis. The main protease (Mpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative virus for COVID-19, represent an effective target for the development of a new drug/vaccine because it is well-conserved and plays a vital role in viral replication. Mpro inhibition can stop the replication, transcription as well as recombination of SARS-CoV-2 after the infection and thus can halt the formation of virus particles, making Mpro a viable therapeutic target. Here, we constructed a phytochemical dataset based on a rigorous literature review and explored the probability that various phytochemicals will bind with the main protease using a molecular docking approach. The top three hit compounds, medicagol, faradiol, and flavanthrin, had binding scores of −8.3, −8.6, and −8.8 kcal/mol, respectively, in the docking analysis. These three compounds bind to the active groove, consisting of His41, Cys45, Met165, Met49, Gln189, Thr24, and Thr190, resulting in main protease inhibition. Moreover, the multiple descriptors from the molecular dynamics simulation, including the root-mean-square deviation, root-mean-square fluctuation, solvent-accessible surface area, radius of gyration, and hydrogen bond analysis, confirmed the stable nature of the docked complexes. In addition, absorption, distribution, metabolism, excretion, and toxicity (ADMET) analysis confirmed a lack of toxicity or carcinogenicity for the screened compounds. Our computational analysis may contribute toward the design of an effective drug against the main protease of SARS-CoV-2.

Vaccine complacency and dose distribution inequities limit the benefits of seasonal influenza vaccination, despite a positive trend in use

Sustainable demand for seasonal influenza vaccines is a component of national security strategies for pandemic preparedness. However, the ongoing COVID-19 pandemic has revealed many weaknesses in the capacity of countries to design and execute sustainable vaccination programs. An influenza pandemic remains a global threat and yet there is no global monitoring system for assessing progress towards influenza vaccination coverage targets. The International Federation of Pharmaceutical Manufacturers and Associations’ (IFPMA) Influenza Vaccine Supply International Task Force (IVS) developed a survey method in 2008 to estimate seasonal influenza vaccination coverage rates, which in turn serves as a crude estimate of pandemic preparedness. It provides evidence to guide expanded efforts for pandemic preparedness, specifically for increasing COVID-19 vaccine immunization levels. Furthermore, the results presented herein serve as a proxy for assessing the state of pandemic preparedness at a global and regional level. This paper adds data from 2018 and 2019 to the previous analyses. The current data show an upward or stable global trend in seasonal influenza vaccine dose distributed per 1,000 population with a 7% increase between 2017 and 2018 and 6% increase between 2018 and 2019. However, considerable regional inequities in access to vaccine persist. Three regions, Africa, the Middle-east, and Southeast Asia together account for 50% of the global population but only 6% of distributed seasonal influenza vaccine doses. This is an important finding in the context of the ongoing COVID-19 pandemic, as distribution of influenza vaccine doses in many ways reflects access to COVID-19 vaccines. Moreover, improving seasonal vaccine uptake rates is critical for optimizing the annual benefits by reducing the huge annual influenza-associated societal burdens and by providing protection to vulnerable individuals against serious complications from seasonal influenza infections.

Influenza A-Associated In-Hospital Mortality in Very Older People: Does Inflammation Also Play a Role?

BACKGROUND

The aim of the study was to analyze the clinical manifestations and outcome of the oldest old (people aged ≥85 years) who were admitted to the hospital with a confirmed influenza A virus infection in comparison with younger patients and to assess the role of inflammation in the outcome of influenza infection in this population.

METHODS

This is an observational prospective study including all adult patients with influenza A virus infection hospitalized in a tertiary teaching hospital in Madrid, in 2 consecutive influenza seasons (2016-17 and 2017-18).

RESULTS

Five hundred nine hospitalized patients with influenza A infection were included, of whom 117 (23%) were older than 85 years (median age: 89.3 ± 3.2). We compared the clinical characteristics and outcome with those of the rest of the population (median age: 72.8 ± 15.7). Overall, mortality was higher in older patients (10% vs. 4%; p = 0.03) with no differences in clinical presentation. Patients older than 85 years who ultimately died (12 out of 117) showed increased systemic inflammation expressed by higher levels of C-reactive protein (CRP) and ferritin compared to survivors who were discharged (odds ratio [OR] of CRP >20 mg/dL: 5.16, 95% confidence interval [CI]: 1.29-20.57, and OR of ferritin >500 mg: 4.3, 95% CI: 1.04-17.35).

CONCLUSIONS

Patients aged 85 and older with influenza A virus infection presented a higher in-hospital mortality than younger subjects. CRP and ferritin levels were higher in the oldest old who died, suggesting that inflammation could play a key role in the outcome of this subset of patients.

Development of a Novel Live Attenuated Influenza A Virus Vaccine Encoding the IgA-Inducing Protein

Live attenuated influenza virus (LAIV) vaccines elicit a combination of systemic and mucosal immunity by mimicking a natural infection. To further enhance protective mucosal responses, we incorporated the gene encoding the IgA-inducing protein (IGIP) into the LAIV genomes of the cold-adapted A/Leningrad/134/17/57 (H2N2) strain (caLen) and the experimental attenuated backbone A/turkey/Ohio/313053/04 (H3N2) (OH/04att). Incorporation of IGIP into the caLen background led to a virus that grew poorly in prototypical substrates. In contrast, IGIP in the OH/04att background (IGIP-H1att) virus grew to titers comparable to the isogenic backbone H1att (H1N1) without IGIP. IGIP-H1att- and H1caLen-vaccinated mice were protected against lethal challenge with a homologous virus. The IGIP-H1att vaccine generated robust serum HAI responses in naïve mice against the homologous virus, equal or better than those obtained with the H1caLen vaccine. Analyses of IgG and IgA responses using a protein microarray revealed qualitative differences in humoral and mucosal responses between vaccine groups. Overall, serum and bronchoalveolar lavage samples from the IGIP-H1att group showed trends towards increased stimulation of IgG and IgA responses compared to H1caLen samples. In summary, the introduction of genes encoding immunomodulatory functions into a candidate LAIV can serve as natural adjuvants to improve overall vaccine safety and efficacy.

National Early Warning Score for predicting intensive care unit admission among elderly patients with influenza infections in the emergency department: an effective disposition tool during the influenza season

OBJECTIVE

During the influenza epidemic season, the fragile elderlies are not only susceptible to influenza infections, but are also more likely to develop severe symptoms and syndromes. Such circumstances may pose a significant burden to the medical resources especially in the emergency department (ED). Disposition of the elderly patients with influenza infections to either the ward or intensive care unit (ICU) accurately is therefore a crucial issue.

STUDY DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

Elderly patients (≥65 years) with influenza visiting the ED of a medical centre between 1 January 2010 and 31 December 2015.

PRIMARY OUTCOME MEASURES

Demographic data, vital signs, medical history, subtype of influenza, national early warning score (NEWS) and outcomes (mortality) were analysed. We investigated the ability of NEWS to predict ICU admission via logistic regression and the receiver operating characteristic (ROC) analysis.

RESULTS

We included 409 geriatric patients in the ED with a mean age of 79.5 years and approximately equal sex ratio. The mean NEWS ±SD was 3.4±2.9, and NEWS ≥8 was reported in 11.0% of the total patients. Logistic regression revealed that NEWS ≥8 predicted ICU admission with an OR of 5.37 (95% CI 2.61 to 11.04). The Hosmer-Lemeshow goodness-of-fit test was calculated as 0.95, and the adjusted area under the ROC was 0.72. An NEWS ≥8 is associated with ICU-admission and may help to triage elderly patients with influenza infections during the influenza epidemic season.

CONCLUSION

The high specificity of NEWS ≥8 to predict ICU admission in elderly patients with influenza infection during the epidemic season may avoid unnecessary ICU admissions and ensure proper medical resource allocation.

Phytochemicals from Plant Foods as Potential Source of Antiviral Agents: An Overview

To date, the leading causes of mortality and morbidity worldwide include viral infections, such as Ebola, influenza virus, acquired immunodeficiency syndrome (AIDS), severe acute respiratory syndrome (SARS) and recently COVID-19 disease, caused by the SARS-CoV-2 virus. Currently, we can count on a narrow range of antiviral drugs, especially older generation ones like ribavirin and interferon which are effective against viruses in vitro but can often be ineffective in patients. In addition to these, we have antiviral agents for the treatment of herpes virus, influenza virus, HIV and hepatitis virus. Recently, drugs used in the past especially against ebolavirus, such as remdesivir and favipiravir, have been considered for the treatment of COVID-19 disease. However, even if these drugs represent important tools against viral diseases, they are certainly not sufficient to defend us from the multitude of viruses present in the environment. This represents a huge problem, especially considering the unprecedented global threat due to the advancement of COVID-19, which represents a potential risk to the health and life of millions of people. The demand, therefore, for new and effective antiviral drugs is very high. This review focuses on three fundamental points: (1) presents the main threats to human health, reviewing the most widespread viral diseases in the world, thus describing the scenario caused by the disease in question each time and evaluating the specific therapeutic remedies currently available. (2) It comprehensively describes main phytochemical classes, in particular from plant foods, with proven antiviral activities, the viruses potentially treated with the described phytochemicals. (3) Consideration of the various applications of drug delivery systems in order to improve the bioavailability of these compounds or extracts. A PRISMA flow diagram was used for the inclusion of the works. Taking into consideration the recent dramatic events caused by COVID-19 pandemic, the cry of alarm that denounces critical need for new antiviral drugs is extremely strong. For these reasons, a continuous systematic exploration of plant foods and their phytochemicals is necessary for the development of new antiviral agents capable of saving lives and improving their well-being.

Squalene-Based Influenza Vaccine Adjuvants and Their Impact on the Hemagglutinin-Specific B Cell Response

Influenza infections continue to cause significant annual morbidity and mortality despite ongoing influenza vaccine research. Adjuvants are administered in conjunction with influenza vaccines to enhance the immune response and strengthen protection against disease. Squalene-based emulsion adjuvants including MF59, AS03, and AF03, are registered for administration with influenza vaccines and are widely used in many countries. Squalene-based emulsion adjuvants induce a strong innate immune response, enhancing antigen presentation both quantitively and qualitatively to generate strong B cell responses and antibody production. They also diversify the reactivity profiles and strengthen the affinities of antibodies against the influenza hemagglutinin, increasing protection across virus clades. In this review, we consider the mechanisms of the enhancement of innate and adaptive immune responses by squalene-based emulsionSE adjuvants and the resulting increase in magnitude and breadth of hemagglutinin-specific B cell responses. We relate observed effects of SE adjuvants and current mechanistic understandings to events in responding lymph nodes. These insights will guide the rational design and optimization of influenza vaccines to provide broad and effective protection.

Spread of Influenza Viruses in Poland and Neighboring Countries in Seasonal Terms

In Poland, flu supervision is coordinated by the National Influenza Center at the National Institute of Public Health-National Institute of Hygiene. In this publication, we want to determine geographical trends in influenza virus circulation in the region. A detailed analysis of virological and epidemiological data showed the course of the epidemic season in Poland, as well as in neighboring countries. The spatial differentiation of the incidence of infection between voivodships was examined, as well as compared to countries that border a given voivodship. The results show a significant variation in the incidence of infection in terms of time and space. This points to the need to increase the number of tests and to raise awareness among health care professionals and the public about the probability of an influenza pandemic, as undetected viruses can spread further into the European Union.

Potential Medicinal Plants for the Treatment of Dengue Fever and Severe Acute Respiratory Syndrome-Coronavirus

While dengue virus (DENV) infection imposes a serious challenge to the survival of humans worldwide, severe acute respiratory syndrome-coronavirus (SARS-CoV) remains the most devastating pandemic in human history. A significant number of studies have shown that plant-derived substances could serve as potential candidates for the development of safe and efficacious remedies for combating these diseases. Different scientific databases were used to source for literature on plants used against these infections. Thirty-five studies described the traditional use of 25 species from 20 families for treating DENV infection with Carica papaya and Euphorbia hirta were the most widely used across different regions. 13 in vivo studies, 32 in vitro studies, and eight clinical studies were conducted on 30 species from 25 families against different DENV serotypes, while plants from 13 families were reported to inhibit different forms of SARS-CoV, all of which were investigated through in vitro studies. Phytoconstituents belonging to various chemical classes were identified to show a wide range of antiviral activity against these infections. Extensive studies on the potentials of medicinal plants are needed to confirm their efficacy. This paper reveals the capabilities of medicinal plants and their phytochemicals in inhibiting DENV and SARS-CoV infections.

Thwarted belongingness and perceived burdensomeness explain the associations of COVID-19 social and economic consequences to suicide risk

OBJECTIVE

The social and economic consequences of COVID-19 and related public health interventions aimed at slowing the spread of the virus have been proposed to increase suicide risk. However, no research has examined these relations. This study examined the relations of two COVID-19 consequences (i.e., stay-at-home orders and job loss) to suicide risk through thwarted belongingness, perceived burdensomeness, and loneliness.

METHOD

Online data from a nationwide community sample of 500 adults (mean age = 40) from 45 states were collected between March 27 and April 5, 2020. Participants completed measures assessing thwarted belongingness, perceived burdensomeness, loneliness, and suicide risk, as well as whether they (a) were currently under a stay-at-home order and (b) had experienced a recent job loss due to the pandemic.

RESULTS

Results revealed a significant indirect relation of stay-at-home order status to suicide risk through thwarted belongingness. Further, whereas recent job loss was significantly correlated with suicide risk, neither the direct relation of job loss to suicide risk (when accounting for their shared relations to perceived burdensomeness) nor the indirect relation through perceived burdensomeness was significant.

CONCLUSIONS

Results highlight the potential benefits of interventions targeting thwarted belongingness and perceived burdensomeness to offset suicide risk during this pandemic.

Antiviral properties of chalcones and their synthetic derivatives: a mini review

Chalcones (natural or synthetic derivatives) are aromatic ketones possessing a central backbone that form a core for variety important compounds with different substitutions. Recent scientific advances show that chalcones exhibit different bio-medical activities, including antiviral, which is related to the variety substitutions. This review provides general information on the origin, sources, virucidal and direct antiviral properties of chalcones in vitro, as well as a brief overview of the possible application and molecular modes of action of these compounds. The antiviral effect of chalcones probably results from the disruption of the different stage of viral replication cycle, inhibition of viral or cell enzymes, induction of apoptosis and others. Structural requirements for antiviral activities vary according to the mechanisms of action. Based on the published information, it could be considered that synthetic chalcones are very perspective antiviral candidates and deserve further studies for elucidating of their pharmacological potential.

Antiviral effect of phytochemicals from medicinal plants: Applications and drug delivery strategies

Viral infections affect three to five million patients annually. While commonly used antivirals often show limited efficacy and serious adverse effects, herbal extracts have been in use for medicinal purposes since ancient times and are known for their antiviral properties and more tolerable side effects. Thus, naturally based pharmacotherapy may be a proper alternative for treating viral diseases. With that in mind, various pharmaceutical formulations and delivery systems including micelles, nanoparticles, nanosuspensions, solid dispersions, microspheres and crystals, self-nanoemulsifying and self-microemulsifying drug delivery systems (SNEDDS and SMEDDS) have been developed and used for antiviral delivery of natural products. These diverse technologies offer effective and reliable delivery of medicinal phytochemicals. Given the challenges and possibilities of antiviral treatment, this review provides the verified data on the medicinal plants and related herbal substances with antiviral activity, as well as applied strategies for the delivery of these plant extracts and biologically active phytochemicals. Graphical Abstract.

Influenza coverage rates in subjects with chronic heart diseases: results obtained in four consecutive immunisation seasons in the Local Health Unit of Ferrara (North Italy)"

Background

Seasonal influenza epidemics yearly affects 5–15% of the world’s population, resulting in 3–5 million serious cases and up to 650,000 deaths. According to the 2017–2019 Italian National Immunisation Plan, free immunisation is offered to the categories at increased risk of experience the complications of the infection (over 65 years old subjects, pregnant women and individuals with underlying conditions, including chronic heart diseases). Rising evidence suggests that influenza can trigger adverse cardiovascular events therefore the vaccination is recommended for secondary prevention of cardiovascular diseases. Despite this, the influenza coverage rate in subjects with chronic heart disease is underestimated.

Methods

The study investigated the coverage rate in four consecutive influenza seasons (from 2011/2012 to 2014/2015) in subjects that benefit from exemption from paying healthcare costs for chronic heart disease living in Local Health Unit (LHU) of Ferrara (Italy), comparing the databases of exemptions and immunisations.

Results

The levels of influenza vaccine uptake were unstable, reaching the 50.3% in 2011/2012 immunisation season and falling to 42.2% in the following year. Coverage rates increased with increasing age, without achieving the 75% target, neither in over 65 years old subjects. The logistic regression analysis showed that influenza coverage rates were statistically significant different (p < 0.0001, 0.003 only for category of disease in 2011/2012 immunisation season) according to age, district of residence, category of chronic heart disease and length of exemption, but not influenced by gender.

Conclusions

The recommendation of influenza immunisation was weakly followed in individuals with chronic heart diseases. A collaboration between cardiologists, GPs, scientific societies and patient associations could successfully support influenza vaccine uptake.

Trust, but customize: federalism's impact on the Canadian COVID-19 response

This article explores how Canadian federalism, with its complex mix of competencies, and the country's punctuated gradualism policy style interface with urgent, complex decision-making like the COVID-19 pandemic. We find that while punctuated gradualism favors tailored responses to pandemic management it is weaker when coordination and resourcing are to be undertaken during non-crisis situations and that, while the level of cooperation among Canadian jurisdictions has progressively increased over the years, policy is still almost exclusively handled at the federal, provincial and territorial levels. Furthermore, the model appears to have critical 'blind spots' in terms of vulnerable communities that do not emerge as such until after a crisis hits.

Characteristics and outcomes of critically ill patients with influenza A (H1N1) in the Western Balkans during the 2019 post-pandemic season

Background

This study looked at the characteristics and outcomes of critically ill patients with confirmed influenza A (H1N1) pdm09 infection in the Western Balkans in the post-pandemic period.

Materials and Methods

This retrospective observational study of medical records and associated data collected during the post-pandemic period included all mechanically ventilated adult patients of two university-affiliated hospitals of the Western Balkans between 1 January and 31 March 2019 who had influenza A (H1N1) pdm09 infection confirmed by real-time reverse transcriptase-polymerase chain reaction from nasopharyngeal swab specimens and respiratory secretions.

Results

The study included 89 patients, 49 males (55.1%), aged 56.09 ± 12.64 years. The median time from shift from hospital time to intensive care unit was 1 day (range: 1-2). In the post-pandemic period, cases observed in this study were found to have the following comorbidities: cardiovascular diseases in 44 (49.4%) patients and diabetes in 21 (23.6%) patients. Thirty-one patients (34.8%) in this study were obese. All 89 patients (100%) experienced some degree of acute respiratory distress syndrome, and 39 (44%) had multiorgan failure. Eighty-three patients (93%) were intubated and mechanically ventilated, 6 (7%) received non-invasive mechanical ventilation, 12 (13%) were treated with vvECMO and 36 (40%) received renal replacement therapy. Vasoactive support was needed by 56 (63%) patients. The median duration of mechanical ventilation was 9 (6-15.5) days. The hospital mortality rate was 44%.

Conclusion

Critically ill patients with confirmed influenza A (H1N1) pdm09 infection in the post-pandemic season were older, required vasoactive drugs more often, and there was a trend of higher survival compared to H1N1 infection patients in the previous pandemic seasons.

Epidemiology, Diagnosis, Treatment, and Prevention of Influenza Infection in Oncology Patients

Influenza infection causes increased morbidity and higher mortality in patients receiving treatment of underlying cancer, particularly in those with hematological malignancy or patients who have undergone hematopoietic stem-cell transplantation. The illness is characterized by seasonality and nonspecific clinical manifestations of upper respiratory infection at a time when other respiratory illnesses are common in the community, making the diagnosis challenging. However, accurate and timely diagnosis by new molecular techniques is crucial in the management of immunocompromised patients, because delays in initiating appropriate therapy can have devastating consequences. Emergence of viral resistance to currently used antiviral agents is of concern, particularly in immunocompromised hosts, and warrants continued monitoring and surveillance. Early and effective treatment improves outcomes, but optimal therapeutic strategies in patients with cancer are not well defined. Health care and research efforts should focus on defining treatment guidelines in patients with cancer and attempt to improve on current vaccination strategies.

Prevention of influenza virus infection and transmission by intranasal administration of a porous maltodextrin nanoparticle-formulated vaccine

Influenza vaccines administered intramuscularly exhibit poor mucosal immune responses in the respiratory tract which is the prime site of the infection. Intranasal vaccination is a potential route for vaccine delivery which has been demonstrated effective in inducing protective immune responses in both systemic and mucosal compartments. For this purpose, nanoparticles have been used as antigen delivery systems to improve antigen capture by immune cells. In this paper we demonstrate efficient delivery of viral antigens to airway epithelial cells, macrophages and dendritic cells, using polysaccharide nanoparticles (NPL), leading to a strong protection against influenza virus infection. A formulation combining split Udorn virus antigens with NPL and the mucosal protein adjuvant CTA1-DD was administered intranasally and resulted in an enhanced specific humoral immune response. Furthermore, NPL carrying split Udorn, with or without CTA1-DD, inhibited virus transmission from infected to uninfected naive mice. These results demonstrate that an intranasal delivery system combining NPL, mucosal adjuvant CTA1-DD and split virus antigens confers robust protection against influenza infection and inhibits virus transmission.

Influenza Vaccination in Italian Healthcare Workers (2018-2019 Season): Strengths and Weaknesses. Results of a Cohort Study in Two Large Italian Hospitals

BACKGROUND

Annual vaccination is the most effective way to combat influenza. As influenza viruses evolve, seasonal vaccines are updated annually. Within the European project Development of Robust and Innovative Vaccine Effectiveness (DRIVE), a cohort study involving Italian healthcare workers (HCWs) was carried out during the 2018-2019 season. Two aims were defined: to measure influenza vaccine effectiveness (IVE) against laboratory-confirmed influenza cases and to conduct an awareness-raising campaign to increase vaccination coverage.

METHODS

Each subject enrolled was followed up from enrollment to the end of the study. Each HCW who developed ILI was swabbed for laboratory confirmation of influenza. Influenza viruses were identified by molecular assays. A Cox regression analysis, crude and adjusted for confounding variables, was performed to estimate the IVE.

RESULTS

Among the 4483 HCWs enrolled, vaccination coverage was 32.5%, and 308 ILI cases were collected: 23.4% were positive for influenza (54.2% A(H1N1) pdm09; 45.8% A(H3N2)). No influenza B viruses were detected. No overall IVE was observed. Analyzing the subtypes of influenza A viruses, the IVE was estimated as 45% (95% CI: -59 to 81) for A(H1N1) pdm09.

CONCLUSIONS

Vaccination coverage among HCWs increased. Study difficulties and the circulation of drifted variants of A(H3N2) could partly explain the observed IVE.

The human antibody response to influenza A virus infection and vaccination

The adaptive immune response to influenza virus infection is multifaceted and complex, involving antibody and cellular responses at both systemic and mucosal levels. Immune responses to natural infection with influenza virus in humans are relatively broad and long-lived, but influenza viruses can escape from these responses over time owing to their high mutation rates and antigenic flexibility. Vaccines are the best available countermeasure against infection, but vaccine effectiveness is low compared with other viral vaccines, and the induced immune response is narrow and short-lived. Furthermore, inactivated influenza virus vaccines focus on the induction of systemic IgG responses but do not effectively induce mucosal IgA responses. Here, I review the differences between natural infection and vaccination in terms of the antibody responses they induce and how these responses protect against future infection. A better understanding of how natural infection induces broad and long-lived immune responses will be key to developing next-generation influenza virus vaccines.

Seasonal influenza vaccination among older adults in Jordan: prevalence, knowledge, and attitudes

Objectives: The current study aimed to evaluate the prevalence, level of knowledge and attitudes to seasonal influenza vaccination among older adults in Jordan. Methods: This was a cross-sectional study in which a close-ended questionnaire was administered to older adults (65 years or older) in two major cities in Jordan between May 2018 and July 2018. A p-value of less than 0.05 was considered the cutoff level for statistical significance. Results: Among 500 participants, only 1.2% (n = 6) received a seasonal influenza vaccine during the previous year. In assessing influenza disease and influenza vaccine knowledge, 47.8% had good knowledge. Around 61% of older adults reported influenza vaccine is effective against preventing influenza however, 49.8% reported that influenza could be treated with the influenza vaccine. Moreover, 27% thought the influenza vaccine is important for older adults. In terms of attitudes toward the vaccine, 24.6% had positive attitudes and 40.6% strongly agreed/agreed that influenza is a serious disease in older adults and they should take the influenza vaccine to prevent influenza. Conclusion: The results of this study showed an extremely poor influenza vaccination rate among older adults and a low level of influenza vaccination knowledge and attitudes.

Ergosterol peroxide suppresses influenza A virus-induced pro-inflammatory response and apoptosis by blocking RIG-I signaling

Ergosterol peroxide has been shown to exhibit anti-tumor, antioxidant and anti-bacterial properties. However, the effects of ergosterol peroxide isolated from the herbal Baphicacanthus cusia root on influenza virus infection remain poorly understood. In the present study, ergosterol peroxide (compound 22) was obtained from the B. cusia root and subjected to investigation regarding its immunoregulatory effect on influenza A virus (IAV)-induced inflammation in A549 human alveolar epithelial cells. The structure of compound 22 isolated from B. cusia root. was elucidated by NMR analyses. Structure determination showed that the chemical structure of compound 22 closely resembles that of ergosterol peroxide. We observed that ergosterol peroxide treatment significantly suppressed IAV-induced upregulation of RIG-I expression. Additionally, ergosterol peroxide inhibited the activation of RIG-I downstream signaling pathways, including p38 MAP kinase and NF-κB, which ultimately resulted in the reduced production of an array of pro-inflammatory mediators and interferons (IFN-β and IFN-λ1). Interestingly, inhibitory effects of ergosterol peroxide on the expression of IFNs did not affect the expression of antiviral effectors or enhance viral replication. On the other hand, ergosterol peroxide effectively abolished the amplified production of pro-inflammatory mediators in cells pretreated with IFN-β (500 ng/ml) prior to IAV infection. Moreover, Annexin V and Hoechst 33258 staining revealed that increased apoptosis of IAV-infected cells was reversed by the presence of ergosterol peroxide. Our findings suggest that ergosterol peroxide from the B. cusia root suppressed IAV-associated inflammation and apoptosis via blocking RIG-I signaling, which may serve as a supplementary approach to the treatment of influenza.

A Glycolipid Adjuvant, 7DW8-5, Enhances the Protective Immune Response to the Current Split Influenza Vaccine in Mice

Vaccination is an effective strategy to control influenza disease. Adjuvants enhance the efficacy of vaccines, but few adjuvants are approved for human use, so novel, safe, and effective adjuvants are urgently needed. The glycolipid adjuvant 7DW8-5 has shown adjuvanticity to malaria vaccine; however, its adjuvant effect for seasonal influenza vaccine remains unknown. Here, we evaluated the adjuvanticity of 7DW8-5 to a quadrivalent split influenza vaccine in a mouse model. 7DW8-5 significantly enhanced virus-specific antibody production when administrated with influenza vaccine compared with that of vaccine alone; 10 μg of 7DW8-5 induced similar antibody levels to those induced by alum. Mouse body weight loss was reduced and, notably, the survival rate was increased in the vaccine plus 7DW8-5 group compared with that in the vaccine plus alum group. Our results indicate that the glycolipid 7DW8-5 is a promising adjuvant for influenza vaccine.

Effect of homeostatic T-cell proliferation in the vaccine responsiveness against influenza in elderly people

Background

Seasonal influenza virus infection is a significant cause of morbimortality in the elderly. However, there is poor vaccine efficacy in this population due to immunosenescence. We aimed to explore several homeostatic parameters in the elderly that could impact influenza vaccine responsiveness.

Methods

Subjects (> 60 years old) who were vaccinated against influenza virus were included, and the vaccine response was measured by a haemagglutination inhibition (HAI) test. At baseline, peripheral CD4 and CD8 T-cells were phenotypically characterized. Thymic function and the levels of different inflammation-related biomarkers, including Lipopolysaccharide Binding Protein (LBP) and anti-cytomegalovirus (CMV) IgG antibodies, were also measured.

Results

Influenza vaccine non-responders showed a tendency of higher frequency of regulatory T-cells (Tregs) before vaccination than responders (1.49 [1.08–1.85] vs. 1.12 [0.94–1.63], respectively, p = 0.061), as well as higher expression of the proliferation marker Ki67 in Tregs and different CD4 and CD8 T-cell maturational subsets. The levels of inflammation-related biomarkers correlated with the frequencies of different proliferating T-cell subsets and with thymic function (e.g., thymic function with D-dimers, r = − 0.442, p = 0.001).

Conclusions

Age-related homeostatic dysregulation involving the proliferation of CD4 and CD8 T-cell subsets, including Tregs, was related to a limited responsiveness to influenza vaccination and a higher inflammatory status in a cohort of elderly people.

Electronic supplementary material

The online version of this article (10.1186/s12979-019-0154-y) contains supplementary material, which is available to authorized users.

Effectiveness of an intervention campaign on influenza vaccination of professionals in nursing homes: A cluster-randomized controlled trial

BACKGROUND

Seasonal influenza has a major individual and collective impact, especially among the elderly living in nursing homes. To prevent infection by influenza viruses, vaccination of residents and professionals is an essential measure. However, while the vaccination rates of residents are generally high (>85%), rates among professionals are generally approximately 20%. To evaluate the effectiveness of an intervention campaign on the improvement of the influenza vaccination rate of professionals, a regional intervention study was proposed for nursing homes during the 2014-15 season.

METHODS

Cluster-randomized controlled trial (with a nursing home representing a cluster). In the intervention group, a campaign on influenza vaccination was offered to staff, combining different teaching aids in a multimodal approach. In the control group, no intervention was proposed. The primary endpoint was the rate of influenza vaccination among staff. Before and after the study, professionals were asked to complete short questionnaires on their perceptions of influenza vaccination. A multilevel analysis was carried out to compare the vaccination rates between the 2 groups and their evolution before/after the winter period.

RESULTS

A total of 32 nursing homes were randomized, and 6 were excluded. Initial vaccination rates were 27.6% in the intervention group and 24.2% in the control group (p = 0.16). After the study, these rates increased to 33.7% and 22.9%, respectively, which was a relative difference of +22.1% in the intervention group compared to -5.4% in the control group, p = 0.0025.

CONCLUSIONS

Despite professionals' reluctance to be vaccinate, participation in a promotional campaign with a pragmatic approach has increased the rate of influenza vaccination. The approach will be offered to all nursing homes in the region after revision of the tools to enhance their ease of use and pedagogical messages focused on the direct benefits to professionals.

Hormonal Regulation of Physiology, Innate Immunity and Antibody Response to H1N1 Influenza Virus Infection During Pregnancy

In 2009, the H1N1 swine flu pandemic highlighted the vulnerability of pregnant women to influenza viral infection. Pregnant women infected with influenza A virus were at increased risk of hospitalization and severe acute respiratory distress syndrome (ARDS), which is associated with high mortality, while their newborns had an increased risk of pre-term birth or low birth weight. Pregnant women have a unique immunological profile modulated by the sex hormones required to maintain pregnancy, namely progesterone and estrogens. The role of these hormones in coordinating maternal immunotolerance in uterine tissue and cellular subsets has been well researched; however, these hormones have wide-ranging effects outside the uterus in modulating the immune response to disease. In this review, we compile research findings in the clinic and in animal models that elaborate on the unique features of H1N1 influenza A viral pathogenesis during pregnancy, the crosstalk between innate immune signaling and hormonal regulation during pregnancy, and the role of pregnancy hormones in modulating cellular responses to influenza A viral infection at mid-gestation. We highlight the ways in which lung architecture and function is stressed by pregnancy, increasing baseline inflammation prior to infection. We demonstrate that infection disrupts progesterone production and upregulates inflammatory mediators, such as cyclooxygenase-2 (COX-2) and prostaglandins, resulting in pre-term labor and spontaneous abortions. Lastly, we profile the ways in which pregnancy alters innate and adaptive cellular immune responses to H1N1 influenza viral infection, and the ways in which these protect fetal development at the expense of effective long-term immune memory. Thus, we highlight advancements in the field of reproductive immunology in response to viral infection and illustrate how that knowledge might be used to develop more effective post-infection therapies and vaccination strategies.

Alternative Strategy for a Quadrivalent Live Attenuated Influenza Virus Vaccine

Seasonal influenza viruses infect 1 billion people worldwide and are associated with ∼500,000 deaths annually. In addition, the never-ending emergence of zoonotic influenza viruses associated with lethal human infections and of pandemic concern calls for the development of better vaccines and/or vaccination strategies against influenza virus. Regardless of the strategy, novel influenza virus vaccines must aim at providing protection against both seasonal influenza A and B viruses. In this study, we tested an alternative quadrivalent live attenuated influenza virus vaccine (QIV) formulation whose individual components have been previously shown to provide protection. We demonstrate in proof-of principle studies in mice that the QIV provides effective protection against lethal challenge with either influenza A or B virus.

Influenza virus infections continue to pose a major public health threat worldwide associated with seasonal epidemics and sporadic pandemics. Vaccination is considered the first line of defense against influenza. Live attenuated influenza virus vaccines (LAIVs) may provide superior responses compared to inactivated vaccines because the former can better elicit a combination of humoral and cellular responses by mimicking a natural infection. Unfortunately, during the 2013–2014, 2014–2015, and 2015–2016 seasons, concerns emerged about the effectiveness of the only LAIV approved in the United States that prevented the Advisory Committee on Immunization Practices (ACIP) from recommending its use. Such drawbacks open up the opportunity for alternative LAIV strategies that could overcome such concerns. Previously, we developed a combined strategy of temperature-sensitive mutations in the PB2 and PB1 segments and an epitope tag in the C terminus of PB1 that effectively attenuates influenza A viruses of avian and mammalian origin. More recently, we adopted a similar strategy for influenza B viruses. The resulting attenuated (att) influenza A and B viruses were safe, immunogenic, and protective against lethal influenza virus challenge in a variety of animal models. In this report, we provide evidence of the potential use of our att strategy in a quadrivalent LAIV (QIV) formulation carrying H3N2 and H1N1 influenza A virus subtype viruses and two antigenic lineages of influenza B viruses. In naive DBA/2J mice, two doses of the QIV elicited hemagglutination inhibition (HI) responses with HI titers of ≥40 and effectively protected against lethal challenge with prototypical pandemic H1N1 influenza A and influenza B virus strains.

IMPORTANCE Seasonal influenza viruses infect 1 billion people worldwide and are associated with ∼500,000 deaths annually. In addition, the never-ending emergence of zoonotic influenza viruses associated with lethal human infections and of pandemic concern calls for the development of better vaccines and/or vaccination strategies against influenza virus. Regardless of the strategy, novel influenza virus vaccines must aim at providing protection against both seasonal influenza A and B viruses. In this study, we tested an alternative quadrivalent live attenuated influenza virus vaccine (QIV) formulation whose individual components have been previously shown to provide protection. We demonstrate in proof-of principle studies in mice that the QIV provides effective protection against lethal challenge with either influenza A or B virus.

A Highly Potent and Broadly Neutralizing H1 Influenza-Specific Human Monoclonal Antibody

Influenza’s propensity for antigenic drift and shift, and to elicit predominantly strain specific antibodies (Abs) leaves humanity susceptible to waves of new strains with pandemic potential for which limited or no immunity may exist. Subsequently new clinical interventions are needed. To identify hemagglutinin (HA) epitopes that if targeted may confer universally protective humoral immunity, we examined plasmablasts from a subject that was immunized with the seasonal influenza inactivated vaccine, and isolated a human monoclonal Ab (mAb), KPF1. KPF1 has broad and potent neutralizing activity against H1 influenza viruses, and recognized 83% of all H1 isolates tested, including the pandemic 1918 H1. Prophylactically, KPF1 treatment resulted in 100% survival of mice from lethal challenge with multiple H1 influenza strains and when given as late as 72 h after challenge with A/California/04/2009 H1N1, resulted in 80% survival. KPF1 recognizes a novel epitope in the HA globular head, which includes a highly conserved amino acid, between the Ca and Cb antigenic sites. Although recent HA stalk-specific mAbs have broader reactivity, their potency is substantially limited, suggesting that cocktails of broadly reactive and highly potent HA globular head-specific mAbs, like KPF1, may have greater clinical feasibility for the treatment of influenza infections.