Novel swine-origin influenza A virus in humans: another pandemic knocking at the door

Miniaturized MXene-based electrochemical biosensors for virus detection

The timely control of infectious diseases can prevent the spread of infections and mitigate the significant socio-economic damage witnessed during recent pandemics. Diagnostic methods play a significant role in detecting highly contagious agents, such as viruses, to prevent further transmission. The emergence of advanced point-of-care techniques offers several advantages over conventional approaches for detecting infectious agents. These techniques are highly sensitive, rapid, can be miniaturized, and are cost-effective. Recently, MXene-based 2D nanocomposites have proven beneficial for fabricating electrochemical biosensors due to their suitable electrical, optical, and mechanical properties. This article covers electrochemical biosensors based on MXene nanocomposite for the detection of viruses, along with the associated challenges and future possibilities. Additionally, we highlight various conventional techniques for the detection of infectious agents, discussing their pros and cons. We delve into the challenges faced during the fabrication of MXene-based biosensors and explore future endeavors. It is anticipated that the information presented in this work will pave the way for the development of Point-of-Care (POC) devices capable of sensitive and selective virus detection, enhancing preparedness for ongoing and future pandemics.

Holistic One Health Surveillance Framework: Synergizing Environmental, Animal, and Human Determinants for Enhanced Infectious Disease Management

Recent pandemics, including the COVID-19 outbreak, have brought up growing concerns about transmission of zoonotic diseases from animals to humans. This highlights the requirement for a novel approach to discern and address the escalating health threats. The One Health paradigm has been developed as a responsive strategy to confront forthcoming outbreaks through early warning, highlighting the interconnectedness of humans, animals, and their environment. The system employs several innovative methods such as the use of advanced technology, global collaboration, and data-driven decision-making to come up with an extraordinary solution for improving worldwide disease responses. This Review deliberates environmental, animal, and human factors that influence disease risk, analyzes the challenges and advantages inherent in using the One Health surveillance system, and demonstrates how these can be empowered by Big Data and Artificial Intelligence. The Holistic One Health Surveillance Framework presented herein holds the potential to revolutionize our capacity to monitor, understand, and mitigate the impact of infectious diseases on global populations.

To Be Frail or Not to Be Frail: This Is the Question-A Critical Narrative Review of Frailty

Many factors have contributed to rendering frailty an emerging, relevant, and very popular concept. First, many pandemics that have affected humanity in history, including COVID-19, most recently, have had more severe effects on frail people compared to non-frail ones. Second, the increase in human life expectancy observed in many developed countries, including Italy has led to a rise in the percentage of the older population that is more likely to be frail, which is why frailty is much a more common concern among geriatricians compared to other the various health-care professionals. Third, the stratification of people according to the occurrence and the degree of frailty allows healthcare decision makers to adequately plan for the allocation of available human professional and economic resources. Since frailty is considered to be fully preventable, there are relevant consequences in terms of potential benefits both in terms of the clinical outcome and healthcare costs. Frailty is becoming a popular, pervasive, and almost omnipresent concept in many different contexts, including clinical medicine, physical health, lifestyle behavior, mental health, health policy, and socio-economic planning sciences. The emergence of the new "science of frailty" has been recently acknowledged. However, there is still debate on the exact definition of frailty, the pathogenic mechanisms involved, the most appropriate method to assess frailty, and consequently, who should be considered frail. This narrative review aims to analyze frailty from many different aspects and points of view, with a special focus on the proposed pathogenic mechanisms, the various factors that have been considered in the assessment of frailty, and the emerging role of biomarkers in the early recognition of frailty, particularly on the role of mitochondria. According to the extensive literature on this topic, it is clear that frailty is a very complex syndrome, involving many different domains and affecting multiple physiological systems. Therefore, its management should be directed towards a comprehensive and multifaceted holistic approach and a personalized intervention strategy to slow down its progression or even to completely reverse the course of this condition.

Potential for Early Noninvasive COVID-19 Detection Using Electronic-Nose Technologies and Disease-Specific VOC Metabolic Biomarkers

The established efficacy of electronic volatile organic compound (VOC) detection technologies as diagnostic tools for noninvasive early detection of COVID-19 and related coronaviruses has been demonstrated from multiple studies using a variety of experimental and commercial electronic devices capable of detecting precise mixtures of VOC emissions in human breath. The activities of numerous global research teams, developing novel electronic-nose (e-nose) devices and diagnostic methods, have generated empirical laboratory and clinical trial test results based on the detection of different types of host VOC-biomarker metabolites from specific chemical classes. COVID-19-specific volatile biomarkers are derived from disease-induced changes in host metabolic pathways by SARS-CoV-2 viral pathogenesis. The unique mechanisms proposed from recent researchers to explain how COVID-19 causes damage to multiple organ systems throughout the body are associated with unique symptom combinations, cytokine storms and physiological cascades that disrupt normal biochemical processes through gene dysregulation to generate disease-specific VOC metabolites targeted for e-nose detection. This paper reviewed recent methods and applications of e-nose and related VOC-detection devices for early, noninvasive diagnosis of SARS-CoV-2 infections. In addition, metabolomic (quantitative) COVID-19 disease-specific chemical biomarkers, consisting of host-derived VOCs identified from exhaled breath of patients, were summarized as possible sources of volatile metabolic biomarkers useful for confirming and supporting e-nose diagnoses.

Variant influenza: connecting the missing dots

BACKGROUND

In June 2009, the World Health Organization declared a new pandemic, the 2009 swine influenza pandemic (swine flu). The symptoms of the swine flu pandemic causing strain were comparable to most of the symptoms noted by seasonal influenza.

AREA COVERED

Zoonotic viruses that caused the swine flu pandemic and its preventive measures.

EXPERT OPINION

As per Centers for Disease Control and Prevention (CDC), the clinical manifestations in humans produced by the 2009 H1N1 'swine flu' virus were equivalent to the manifestations caused by related flu strains. The H1N1 vaccination was the most successful prophylactic measure since it prevented the virus from spreading and reduced the intensity and consequences of the pandemic. Despite the availability of therapeutics, the ongoing evolution and appearance of new strains have made it difficult to develop effective vaccines and therapies. Currently, the CDC recommends yearly flu immunization for those aged 6 months and above. The lessons learned from the A/2009/H1N1 pandemic in 2009 indicated that readiness of mankind toward new illnesses caused by mutant viral subtypes that leap from animals to people must be maintained.

Aerosol transmission of human pathogens: From miasmata to modern viral pandemics and their preservation potential in the Anthropocene record

Ongoing uncertainty over the relative importance of aerosol transmission of COVID-19 is in part rooted in the history of medical science and our understanding of how epidemic diseases can spread through human populations. Ancient Greek medical theory held that such illnesses are transmitted by airborne pathogenic emanations containing particulate matter ("miasmata"). Notable Roman and medieval scholars such as Varro, Ibn al-Khatib and Fracastoro developed these ideas, combining them with early germ theory and the concept of contagion. A widely held but vaguely defined belief in toxic miasmatic mists as a dominant causative agent in disease propagation was overtaken by the science of 19th century microbiology and epidemiology, especially in the study of cholera, which was proven to be mainly transmitted by contaminated water. Airborne disease transmission came to be viewed as burdened by a dubious historical reputation and difficult to demonstrate convincingly. A breakthrough came with the classic mid-20th century work of Wells, Riley and Mills who proved how expiratory aerosols (their "droplet nuclei") could transport still-infectious tuberculosis bacteria through ventilation systems. The topic of aerosol transmission of pathogenic respiratory diseases assumed a new dimension with the mid-late 20th century "Great Acceleration" of an increasingly hypermobile human population repeatedly infected by different strains of zoonotic viruses, and has taken centre stage this century in response to outbreaks of new respiratory infections that include coronaviruses. From a geoscience perspective, the consequences of pandemic-status diseases such as COVID-19, produced by viral pathogens utilising aerosols to infect a human population currently approaching 8 billion, are far-reaching and unprecedented. The obvious and sudden impacts on for example waste plastic production, water and air quality and atmospheric chemistry are accelerating human awareness of current environmental challenges. As such, the "anthropause" lockdown enforced by COVID-19 may come to be seen as a harbinger of change great enough to be preserved in the Anthropocene stratal record.

Simple and Field Amenable Loop-Mediated Isothermal Amplification-Lateral Flow Dipstick Assay for Detection of West Nile Virus in Human Clinical Samples

AIM

West Nile encephalitis caused by infection with the West Nile virus (WNV) is endemic in many regions of the world and is a global public health threat. The aim of this report was to develop a method using colorimetry based reverse-transcription loop-mediated isothermal amplification (cRT-LAMP) and RT-LAMP combined with lateral-flow dipstick (LFD) for rapidly detecting WNV in low-infrastructure settings.

METHODS AND RESULTS

The primers for the cRT-LAMP and RT-LAMP-LFD assay were designed based on env gene of the WNV. Primers concentration, temperature, and time were optimized for cRT-LAMP and RT-LAMP-LFD. The diagnostic performance of the cRT-LAMP and RT-LAMP-LFD assay was evaluated using human serum samples from 110 patients who were clinically suspected to be infected with WNV. The RT-LAMP was performed in a heating block at 63°C for 40 minutes. The LAMP amplicons were visible in the lateral-flow dipstick within 5 minutes. The detection limit of the developed cRT-LAMP and RT-LAMP-LFD assay was 10 copies and this assay showed high degree of specificity for WNV. Compared with quantitative real-time RT-PCR assay, the kappa value of cRT-LAMP and RT-LAMP-LFD were 0.970.

CONCLUSIONS

These results showed that the newly developed WNV specific cRT-LAMP and RT-LAMP-LFD assays can be employed as an alternative method for screening of WN suspected human samples. The results revealed that the assay could potentially identify the virus without interference from human serum samples. Collectively, the all results revealed that cRT-LAMP and RT-LAMP-LFD assay offers suitable field based diagnosis of WNV.

SIGNIFICANCE AND IMPACT OF STUDY

The cRT-LAMP and LAMP-LFD platform for the detection of WNV is rapid, accurate, and simple-to-perform. Our present method has not only a short turnaround time but also avoided cross-contamination problem. Moreover, the use of simple lateral flow dipsticks broadens its application potential to the point-of-care use in resource-limited settings during outbreak situations. To the best of our knowledge this is the first report for the development of cRT-LAMP and LAMP-LFD assay for rapid, simple, specific, and sensitive detection of WNV using human clinical samples and EvaGreen dye.

Understanding the Variability of Certain Biological Properties of H1N1pdm09 Influenza Viruses

The influenza virus continually evolves because of the high mutation rate, resulting in dramatic changes in its pathogenicity and other biological properties. This study aimed to evaluate the evolution of certain essential properties, understand the connections between them, and find the molecular basis for the manifestation of these properties. To that end, 21 A(H1N1)pdm09 influenza viruses were tested for their pathogenicity and toxicity in a mouse model with a ts/non-ts phenotype manifestation and HA thermal stability. The results demonstrated that, for a strain to have high pathogenicity, it must express a toxic effect, have a non-ts phenotype, and have a thermally stable HA. The ancestor A/California/07/2009 (H1N1)pdm influenza virus expressed the non-ts phenotype, after which the cycling trend of the ts/non-ts phenotype was observed in new strains of A(H1N1)pdm09 influenza viruses, indicating that the ratio of the ts phenotype will increase in the coming years. Of the 21 tested viruses, A/South Africa/3626/2013 had the high pathogenicity in the mouse model. Sequence alignment analysis showed that this virus has three unique mutations in the polymerase complex, two of which are in the PB2 gene and one that is in the PB1 gene. Further study of these mutations might explain the distinguishing pathogenicity.

Passive Data Use for Ethical Digital Public Health Surveillance in a Postpandemic World

There is a fundamental need to establish the most ethical and effective way of tracking disease in the postpandemic era. The ubiquity of mobile phones is generating large amounts of passive data (collected without active user participation) that can be used as a tool for tracking disease. Although discussions of pragmatism or economic issues tend to guide public health decisions, ethical issues are the foremost public concern. Thus, officials must look to history and current moral frameworks to avoid past mistakes and ethical pitfalls. Past pandemics demonstrate that the aftermath is the most effective time to make health policy decisions. However, an ethical discussion of passive data use for digital public health surveillance has yet to be attempted, and little has been done to determine the best method to do so. Therefore, we aim to highlight four potential areas of ethical opportunity and challenge: (1) informed consent, (2) privacy, (3) equity, and (4) ownership.

Assay of Fatty Acids and Their Role in the Prevention and Treatment of COVID-19

Since the emergence of COVID-19, concerted worldwide efforts have taken place to minimize global spread of the contagion. Its widespread effects have also facilitated evolution of new strains, such as the delta and omicron variants, which emerged toward the end of 2020 and 2021, respectively. While these variants appear to be no more deadly than the previous alpha, beta, and gamma strains, and widespread population vaccinations notwithstanding, greater virulence makes the challenge of minimizing spread even greater. One of the peculiarities of this virus is the extreme heath impacts, with the great majority of individuals minimally affected, even sometimes unaware of infection, while for a small minority, it is deadly or produces diverse long-term effects. Apart from vaccination, another approach has been an attempt to identify treatments, for those individuals for whom the virus represents a threat of particularly severe health impact(s). These treatments include anti-SARS-CoV-2 monoclonal antibodies, anticoagulant therapies, interleukin inhibitors, and anti-viral agents such as remdesivir. Nutritional factors are also under consideration, and a variety of clinical trials are showing promise for the use of specific fatty acids, or related compounds such as fat-soluble steroid vitamin D, to mitigate the more lethal aspects of COVID-19 by modulating inflammation and by anti-viral effects. Here we explore the potential protective role of fatty acids as a potential prophylactic as well as remedial treatment during viral infections, particularly COVID-19. We present a multiplexed method for the analysis of free and phospholipid bound fatty acids, which may facilitate research into the role of fatty acids as plasma biomarkers and therapeutic agents in minimizing pre- and post-infection health impacts.

Comparing Host Module Activation Patterns and Temporal Dynamics in Infection by Influenza H1N1 Viruses

Influenza is a serious global health threat that shows varying pathogenicity among different virus strains. Understanding similarities and differences among activated functional pathways in the host responses can help elucidate therapeutic targets responsible for pathogenesis. To compare the types and timing of functional modules activated in host cells by four influenza viruses of varying pathogenicity, we developed a new DYNAmic MOdule (DYNAMO) method that addresses the need to compare functional module utilization over time. This integrative approach overlays whole genome time series expression data onto an immune-specific functional network, and extracts conserved modules exhibiting either different temporal patterns or overall transcriptional activity. We identified a common core response to influenza virus infection that is temporally shifted for different viruses. We also identified differentially regulated functional modules that reveal unique elements of responses to different virus strains. Our work highlights the usefulness of combining time series gene expression data with a functional interaction map to capture temporal dynamics of the same cellular pathways under different conditions. Our results help elucidate conservation of the immune response both globally and at a granular level, and provide mechanistic insight into the differences in the host response to infection by influenza strains of varying pathogenicity.

Why has COVID-19 not hit the countries like Nepal yet?

Noble CORONA Virus (COVID-19) is an infectious disease similar form of pneumonia/ SARS-CoV-2- impacting globally. The fear of coronavirus looks pandemic, but its severity is uncertain. Nepal was one of the first nine countries outside of China to report a COVID-19 case. Also, its unpredictability of mode or range of surface, the lifespan of the virus, objects of transmission (a distance of air/air currents, living duration in air, humidity, duration on objects, surface). The first case was found in Wuhan in December 2019 in China. The purpose is to summarize the current information about COVID-19 and to explore in terms of why Nepal is not hitting severely, while other countries are on death toll? We summarized the published articles form the web sources and news, Academic Journals, Ministry of health and population Nepal, WHO/CDC update reports/guidelines, Google search engine. Thematic analysis is made to explore the situation. Although, Nepal has a lack of health services, testing kits, advance lab and protecting equipment (PPE), why COVID-19 does not hit Nepal than China, Europe and North America, it still tremendous uncertainty. Is lockdown, isolation, social distance and quarantine the best ways of prevention? The hypothesis is floating globally - do BCG vaccinated countries are safer than non-user OR due to not having enough kits to screen populations at risk for the virus - while lack of testing a big cause for missing case OR Nepalese have better immune systems? It has attracted global attention. We believe that the COVID-19 is still evolving and it is too early to predict of an outbreak in Nepal. The government needs to increase funding for local health departments, begin planning for future epidemics and be prepared to bolster the economy by supporting consumer spending the midst of a serious outbreak. COVID-19 is a serious health challenge for Nepal, but so far the number of death has been lower than was foretell. It is, therefore essential to carry out more scientific evidence to explore results. Nepalese health services need to maintain up than today and follow lockdown, isolation, social distance and an advance screening test kit through the country.

Polymerase Spiral Reaction Assay for Rapid and Real Time Detection of West Nile Virus From Clinical Samples

West Nile virus (WNV) is a mosquito-borne virus of public health importance. Currently, there is no FDA approved vaccine available against WNV infection in humans. Therefore, the early diagnosis of the WNV infection is important for epidemiologic control and timely clinical management in areas where multiple Flaviviruses are endemic. The present study aimed to develop reverse transcription polymerase spiral reaction (RT-PSR) assay that rapidly and accurately detects the envelope (env) gene of WNV. RT-PSR assay was optimized at 63°C for 60 min using real-time turbidimeter or visual detection by the addition of SYBR Green I dye. The standard curve for RT-PSR assay was generated using the 10-fold serial dilutions of in vitro transcribed WNV RNA. To determine the detection limit of RT-PSR assay, an amplified product of conventional RT-PCR was in vitro transcribed as per standard protocol. The detection limit of the newly developed RT-PSR assay was compared with that of conventional RT-PCR and CDC reported TaqMan real-time RT-PCR using a serial 10-fold dilution of IVT WNV RNA. The detection limit of RT-PSR was found to be 1 RNA copy, which is 100-fold higher than that of conventional RT-PCR (100 copies). This suggests that RT-PSR assay is a valuable diagnostic tool for rapid and real-time detection of WNV in acute-phase serum samples. The assay was validated with a panel of 107 WNV suspected human clinical samples with signs of acute posterior uveitis and onset of febrile illness. Out of 107 samples, 30 were found positive by RT-PSR assay. The specificities of the selected primer sets were established by the absence of cross-reactivity with other closely related members viruses of the Flaviviruses, Alphaviruses, and Morbilliviruses groups. No cross-reactivity was observed with other viruses. To best of our knowledge, this is the first report describing the RT-PSR assay for the detection of RNA virus (WNV) in clinical samples. RT-PSR is a high throughput method and more than 30 reactions can be run at once in real-time turbidimeter. PSR assay has potential to be used for a rapid screening of large number of clinical samples in endemic areas during an outbreak.

The COVID-19 pandemic: the public health reality

The coronavirus disease (COVID-19), while mild in most cases, has nevertheless caused significant mortality. The measures adopted in most countries to contain it have led to colossal social and economic disruptions, which will impact the medium- and long-term health outcomes for many communities. In this paper, we deliberate on the reality and facts surrounding the disease. For comparison, we present data from past pandemics, some of which claimed more lives than COVID-19. Mortality data on road traffic crashes and other non-communicable diseases, which cause more deaths each year than COVID-19 has so far, is also provided. The indirect, serious health and social effects are briefly discussed. We also deliberate on how misinformation, confusion stemming from contrasting expert statements, and lack of international coordination may have influenced the public perception of the illness and increased fear and uncertainty. With pandemics and similar problems likely to re-occur, we call for evidence-based decisions, the restoration of responsible journalism and communication built on a solid scientific foundation.

Development and fit-for-purpose verification of an LC-MS method for quantitation of hemagglutinin and neuraminidase proteins in influenza virus-like particle vaccine candidates

Recombinant influenza Virus-Like Particle (VLP) vaccines are promising vaccine candidates to prevent influenza, contain two major viral antigenic glycoproteins, Hemagglutinin (HA) and Neuraminidase (NA), on the surface of recombinant VLPs. Accurate quantitation of the mass of these antigenic proteins is important to ensure the product quality and proper dosing. Currently, Single Radial Immunodiffusion (SRID) is a recognized assay for determination of the HA immuno-reactive concentration (potency) in vaccine products, based on immuno-reactivity of HA with strain-specific antisera. The SRID assay, however, requires availability of strain-specific and properly calibrated reagents, which can be time-consuming to generate and calibrate. In addition, the assay is not suitable for quantitation of low abundant proteins, such as NA. In order to accelerate the overall production cycle, we have developed and optimized a high-resolution (HR) LC-MS method for absolute quantitation of both HA and NA protein concentrations in influenza VLP vaccine candidates. In this work, we present the method development, optimization and verification of its suitability for the intended purpose, as a prerequisite for its potential application in Quality Control, by assessing specificity, precision and accuracy, detection characteristics, and dynamic linear range. The method can be also used for other HA/NA containing preparations including in-process samples, purified proteins, whole virus preparations, nano-particle and egg-based vaccine preparations, or for calibration of SRID reference antigens.

The Role of EGFR in Influenza Pathogenicity: Multiple Network-Based Approaches to Identify a Key Regulator of Non-lethal Infections

Despite high sequence similarity between pandemic and seasonal influenza viruses, there is extreme variation in host pathogenicity from one viral strain to the next. Identifying the underlying mechanisms of variability in pathogenicity is a critical task for understanding influenza virus infection and effective management of highly pathogenic influenza virus disease. We applied a network-based modeling approach to identify critical functions related to influenza virus pathogenicity using large transcriptomic and proteomic datasets from mice infected with six influenza virus strains or mutants. Our analysis revealed two pathogenicity-related gene expression clusters; these results were corroborated by matching proteomics data. We also identified parallel downstream processes that were altered during influenza pathogenesis. We found that network bottlenecks (nodes that bridge different network regions) were highly enriched in pathogenicity-related genes, while network hubs (highly connected network nodes) were significantly depleted in these genes. We confirmed that this trend persisted in a distinct virus: Severe Acute Respiratory Syndrome Coronavirus (SARS). The role of epidermal growth factor receptor (EGFR) in influenza pathogenesis, one of the bottleneck regulators with corroborating signals across transcript and protein expression data, was tested and validated in additional mouse infection experiments. We demonstrate that EGFR is important during influenza infection, but the role it plays changes for lethal versus non-lethal infections. Our results show that by using association networks, bottleneck genes that lack hub characteristics can be used to predict a gene's involvement in influenza virus pathogenicity. We also demonstrate the utility of employing multiple network approaches for analyzing host response data from viral infections.

PA-X: a key regulator of influenza A virus pathogenicity and host immune responses

PA-X, a fusion protein belonging to influenza A viruses (IAVs), integrating the N-terminal 191 amino acids of PA gene and the ribosomal frame-shifting product that lengthens out to 41 or 61 amino acids. Since its discovery in 2012, multiple functions have been attributed to this small protein, including a process, where wide-spread protein synthesis in infected host cells is shut down (called host shutoff), and viral replication, polymerase activity, viral-induced cell apoptosis, PA nuclear localization, and virulence are modulated. However, many of its proposed functions may be specific to strain, subtype, host, or cell line. In this review, we start by describing the well-defined global host-shutoff ability of PA-X and the potential mechanisms underlying it. We move on to the role played by PA-X in modulating innate and acquired immune responses in the host. We then systematically discuss the role played by PA-X in modulating the virulence of influenza viruses of different subtypes and host origins, and finish with a general overview of the research advances made in identifying the host cell partners that interact with PA-X. To uncover possible clues about the differential effects of PA-X in modulating viral virulence, we focus on systemically evaluating polymorphisms in PA-X from various viral subtypes and hosts, including avian and human H5N1, H5N6, H9N2, and H7N9 viruses. Finally, we conclude with a proposition regarding the possible future research directions for this important protein.

A latex agglutination assay to quantify the amount of hemagglutinin protein in adjuvanted low-dose influenza monovalent vaccines

To formulate inactivated influenza vaccines, the concentration of hemagglutinin (HA) must be accurately determined. The standard test currently used to measure HA in influenza vaccines is the Single Radial Immunodiffusion (SRID) assay. We developed a very rapid, simple and sensitive alternative quantitative HA assay, namely the Latex Agglutination Assay (LAA). The LAA uses the Spherotest® technology, which is based on the agglutination of HA-specific immunoglobulin-coated latex beads. The amount of HA in a sample is calculated from the level of bead agglutination by a simple absorbance measurement at 405nm against a standard curve generated using a monovalent vaccine standard. In less than 2hours, tens of samples could be quantified using the LAA as opposed to 2days for the SRID assay. Ten steps are required to complete an SRID assay as compared to 6 steps for the LAA, from sample preparation through spectrophotometric analysis. Furthermore, the limit of detection of the LAA was found to be approximately 15ng HA/mL, similar to an ELISA, with the quantification of less than 1.8μg HA/mL. The quantification limit of the SRID is usually considered to be approximately 5μg HA/mL. The development of the assay and a comparison of the titers obtained by SRID and LAA for several monovalent vaccines corresponding to various strains were performed. For A/H5N1 and A/H1N1 monovalent vaccines, the LAA was found to be linear and accurate as compared to the SRID. The precision of the LAA was close to that of the standard test, and good reproducibility from one laboratory to another was observed. Moreover, the LAA enabled HA quantification in AlOOH-adjuvanted and in emulsion-adjuvanted low-dose vaccines as well as unadjuvanted vaccines. In conclusion, LAA may be useful to rapidly and accurately measure influenza HA protein in monovalent vaccines, especially in those containing less than 5μg/mL of HA in the presence of an adjuvant.

Secondary Bacterial Infections Associated with Influenza Pandemics

Lower and upper respiratory infections are the fourth highest cause of global mortality (Lozano et al., 2012). Epidemic and pandemic outbreaks of respiratory infection are a major medical concern, often causing considerable disease and a high death toll, typically over a relatively short period of time. Influenza is a major cause of epidemic and pandemic infection. Bacterial co/secondary infection further increases morbidity and mortality of influenza infection, with Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus reported as the most common causes. With increased antibiotic resistance and vaccine evasion it is important to monitor the epidemiology of pathogens in circulation to inform clinical treatment and development, particularly in the setting of an influenza epidemic/pandemic.

Virological Surveillance of Influenza A Subtypes Isolated in 2014 from Clinical Outbreaks in Canadian Swine

Influenza A viruses (IAVs) are respiratory pathogens associated with an acute respiratory disease that occurs year-round in swine production. It is currently one of the most important pathogens in swine populations, with the potential to infect other host species including humans. Ongoing research indicates that the three major subtypes of IAV—H1N1, H1N2, and H3N2—continue to expand in their genetic and antigenic diversity. In this study, we conducted a comprehensive genomic analysis of 16 IAVs isolated from different clinical outbreaks in Alberta, Manitoba, Ontario, and Saskatchewan in 2014. We also examined the genetic basis for probable antigenic differences among sequenced viruses. On the basis of phylogenetic analysis, all 13 Canadian H3N2 viruses belonged to cluster IV, eight H3N2 viruses were part of the IV-C cluster, and one virus belonged to the IV-B and one to the IV-D cluster. Based on standards used in this study, three H3N2 viruses could not be clearly classified into any currently established group within cluster IV (A to F). Three H1N2 viruses were part of the H1α cluster.

Mechanisms of replacement of circulating viruses by seasonal and pandemic influenza A viruses

BACKGROUND

Seasonal influenza causes annual epidemics by the accumulation of antigenic changes. Pandemic influenza occurs through a major antigenic change of the influenza A virus, which can originate from other hosts. Although new antigenic variants of the influenza A virus replace formerly circulating seasonal and pandemic viruses, replacement mechanisms remain poorly understood.

METHODS

A stochastic individual-based SEIR (susceptible-exposed-infectious-recovered) model with two viral strains (formerly circulating old strain and newly emerged strain) was developed for simulations to elucidate the replacement mechanisms.

RESULTS

Factors and conditions of virus and host populations affecting the replacement were identified. Replacement is more likely to occur in tropical regions than temperate regions. The magnitude of the ongoing epidemic by the old strain, herd immunity against the old strain, and timing of appearance of the new strain are not that important for replacement. It is probable that the frequency of replacement by a pandemic virus is higher than a seasonal virus because of the high initial susceptibility and high basic reproductive number of the pandemic virus.

CONCLUSIONS

The findings of this study on replacement mechanisms could lead to a better understanding of virus transmission dynamics and may possibly be helpful in establishing an effective strategy to mitigate the impact of seasonal and pandemic influenza.

Swine flu-have we learnt any lesson from the past?

The world has suffered the pandemics due to swine flu in the past. The present epidemic in India has claimed many lives. Even, after the first outbreak of swine flu in 2009 no concrete efforts are done to prevent this infection. There is an urgent need to take radical steps to prevent such epidemics.

Homeopathic medicines for prevention of influenza and acute respiratory tract infections in children: blind, randomized, placebo-controlled clinical trial

BACKGROUND

Influenza and its complications are common at all ages, especially in children. Vaccines and anti-influenza drugs aim to prevent it. Preventative approaches with favorable risk profiles should be considered for flu, particularly since the evidence of the efficacy of anti-viral drugs is debated.

METHODS

This pragmatic clinical trial was conducted in the Brazilian Public Health System in Petrópolis (BPHSP) with children aged from 1 to 5 years old. The medications used were mainly selected based on in vitro experiments (InfluBio), and in successful qualitative clinical experiences (Homeopathic Complex). Following informed parental consent, subjects were randomly distributed, in a blind manner, to three experimental groups: Homeopathic Complex, Placebo, and InfluBio. BPHSP health agents collected flu and acute respiratory infection symptomatic episodes monthly following the established protocol. The number of these episodes was registered in one year (2009-2010).

RESULTS

Out of the 600 children recruited, 445 (74.17%) completed the study (149: Homeopathic complex; 151: Placebo; 145: InfluBio). The number of flu and acute respiratory infection symptomatic episodes detected in this clinical trial was low; however, it was different between homeopathic groups and placebo (p < 0.001). In the first year post-intervention, 46/151 (30.5%) of children in the placebo group developed 3 or more flu and acute respiratory infection episodes, while there was no episode in the group of 149 children who used Homeopathic Complex, and only 1 episode in the group of 145 (1%) children who received InfluBio.

CONCLUSION

These results suggested that the use of homeopathic medicines minimized the number of flu and acute respiratory infection symptomatic episodes in children, signalizing that the homeopathic prophylactic potential should be investigated in further studies.

Critical assessment of influenza VLP production in Sf9 and HEK293 expression systems

Background

Each year, influenza is responsible for hundreds of thousand cases of illness and deaths worldwide. Due to the virus’ fast mutation rate, the World Health Organization (WHO) is constantly on alert to rapidly respond to emerging pandemic strains. Although anti-viral therapies exist, the most proficient way to stop the spread of disease is through vaccination. The majority of influenza vaccines on the market are produced in embryonic hen’s eggs and are composed of purified viral antigens from inactivated whole virus. This manufacturing system, however, is limited in its production capacity. Cell culture produced vaccines have been proposed for their potential to overcome the problems associated with egg-based production. Virus-like particles (VLPs) of influenza virus are promising candidate vaccines under consideration by both academic and industry researchers.

Methods

In this study, VLPs were produced in HEK293 suspension cells using the Bacmam transduction system and Sf9 cells using the baculovirus infection system. The proposed systems were assessed for their ability to produce influenza VLPs composed of Hemagglutinin (HA), Neuraminidase (NA) and Matrix Protein (M1) and compared through the lens of bioprocessing by highlighting baseline production yields and bioactivity. VLPs from both systems were characterized using available influenza quantification techniques, such as single radial immunodiffusion assay (SRID), HA assay, western blot and negative staining transmission electron microscopy (NSTEM) to quantify total particles.

Results

For the HEK293 production system, VLPs were found to be associated with the cell pellet in addition to those released in the supernatant. Sf9 cells produced 35 times more VLPs than HEK293 cells. Sf9-VLPs had higher total HA activity and were generally more homogeneous in morphology and size. However, Sf9 VLP samples contained 20 times more baculovirus than VLPs, whereas 293 VLPs were produced along with vesicles.

Conclusions

This study highlights key production hurdles that must be overcome in both expression platforms, namely the presence of contaminants and the ensuing quantification challenges, and brings up the question of what truly constitutes an influenza VLP candidate vaccine.

Electronic supplementary material

The online version of this article (doi:10.1186/s12896-015-0152-x) contains supplementary material, which is available to authorized users.

Vaccination against infectious diseases: what is promising?

Vaccination has proven to be one of the best weapons protecting the mankind against infectious diseases. Along with the huge progress in microbiology, numerous highly efficacious and safe vaccines have been produced by conventional technology (cultivation), by the use of molecular biology (genetic modification), or by synthetic chemistry. Sterilising prevention is achieved by the stimulation of antibody production, while the stimulation of cell-mediated immune responses may prevent the outbreak of disease in consequence of an acute or reactivated infection. From several examples, two rules are deduced to evaluate the perspectives of future vaccine developments: They are promising, if (1) the natural infectious disease induces immunity or (2) passive immunisation (transfer of antibodies, adoptive transfer of lymphocytes) is successful in preventing infection.

Crucial role of PA in virus life cycle and host adaptation of influenza A virus

The PA protein is the third subunit of the polymerase complex of influenza A virus. Compared with the other two polymerase subunits (PB2 and PB1), its precise functions are less defined. However, in recent years, advances in protein expression and crystallization technologies and also the reverse genetics, greatly accelerate our understanding of the essential role of PA in virus infection. Here, we first review the current literature on this remarkably multifunctional viral protein regarding virus life cycle, including viral RNA transcription and replication, viral genome packaging and assembly. We then discuss the various roles of PA in host adaption in avian species and mammals, general virus-host interaction, and host protein synthesis shutoff. We also review the recent findings about the novel proteins derived from PA. Finally, we discuss the prospects of PA as a target for the development of new antiviral approaches and drugs.

Announcing Swine Flu and the Interpretation of Pandemic Anxiety

This paper discusses the ways in which 2009 novel swine-origin influenza A (H1N1) was announced and resonated with current pandemic anxieties. In particular, the US Centers for Disease Control and Prevention (CDC) are used as a lens through which recent pandemic anxieties can be analysed and understood. This entails a closer look at the securitisation of public health and the challenges and struggles this may have caused within public health agencies. In that light, CDC' formal entanglement with global health security and its announcement of the H1N1 pandemic are interpreted, followed by an ethnographically informed focus on various people who were engaged in the H1N1 emergency response and their practices and practical struggles in the face of pandemic anxiety.

Analytical technologies for influenza virus-like particle candidate vaccines: challenges and emerging approaches

Influenza virus-like particle vaccines are one of the most promising ways to respond to the threat of future influenza pandemics. VLPs are composed of viral antigens but lack nucleic acids making them non-infectious which limit the risk of recombination with wild-type strains. By taking advantage of the advancements in cell culture technologies, the process from strain identification to manufacturing has the potential to be completed rapidly and easily at large scales. After closely reviewing the current research done on influenza VLPs, it is evident that the development of quantification methods has been consistently overlooked. VLP quantification at all stages of the production process has been left to rely on current influenza quantification methods (i.e. Hemagglutination assay (HA), Single Radial Immunodiffusion assay (SRID), NA enzymatic activity assays, Western blot, Electron Microscopy). These are analytical methods developed decades ago for influenza virions and final bulk influenza vaccines. Although these methods are time-consuming and cumbersome they have been sufficient for the characterization of final purified material. Nevertheless, these analytical methods are impractical for in-line process monitoring because VLP concentration in crude samples generally falls out of the range of detection for these methods. This consequently impedes the development of robust influenza-VLP production and purification processes. Thus, development of functional process analytical techniques, applicable at every stage during production, that are compatible with different production platforms is in great need to assess, optimize and exploit the full potential of novel manufacturing platforms.

Methamphetamine reduces human influenza A virus replication

Methamphetamine (meth) is a highly addictive psychostimulant that is among the most widely abused illicit drugs, with an estimated over 35 million users in the world. Several lines of evidence suggest that chronic meth abuse is a major factor for increased risk of infections with human immunodeficiency virus and possibly other pathogens, due to its immunosuppressive property. Influenza A virus infections frequently cause epidemics and pandemics of respiratory diseases among human populations. However, little is known about whether meth has the ability to enhance influenza A virus replication, thus increasing severity of influenza illness in meth abusers. Herein, we investigated the effects of meth on influenza A virus replication in human lung epithelial A549 cells. The cells were exposed to meth and infected with human influenza A/WSN/33 (H1N1) virus. The viral progenies were titrated by plaque assays, and the expression of viral proteins and cellular proteins involved in interferon responses was examined by Western blotting and immunofluorescence staining. We report the first evidence that meth significantly reduces, rather than increases, virus propagation and the susceptibility to influenza infection in the human lung epithelial cell line, consistent with a decrease in viral protein synthesis. These effects were apparently not caused by meth’s effects on enhancing virus-induced interferon responses in the host cells, reducing viral biological activities, or reducing cell viability. Our results suggest that meth might not be a great risk factor for influenza A virus infection among meth abusers. Although the underlying mechanism responsible for the action of meth on attenuating virus replication requires further investigation, these findings prompt the study to examine whether other structurally similar compounds could be used as anti-influenza agents.

In silico biology of H1N1: molecular modelling of novel receptors and docking studies of inhibitors to reveal new insight in flu treatment

Influenza is an infectious disease caused by RNA viruses of the family Orthomyxoviridae. The new influenza H1N1 viral stain has emerged by the genetic combination of genes from human, pig, and bird's H1N1 virus. The influenza virus is roughly spherical and is enveloped by a lipid membrane. There are two glycoproteins in this lipid membrane; namely, hemagglutinin (HA) which helps in attachment of the viral strain on the host cell surface and neuraminidase (NA) that is responsible for initiation of viral infection. We have developed homology models of both Hemagglutinin and Neuraminidase receptors from H1N1 strains in eastern India. The docking studies of B-Sialic acid and O-Sialic acid in the optimized and energy-minimized homology models show important H-bonding interactions with ALA142, ASP230, GLN231, GLU232, and THR141. This information can be used for structure-based and pharmacophore-based new drug design. We have also calculated ADME properties (Human Oral Absorption (HOA) and % HOA) for Oseltamivir which have been subject of debate for long.

Cell culture-derived influenza vaccines from Vero cells: a new horizon for vaccine production

In the 20th century, three influenza pandemics killed approximately 100 million people. The traditional method of influenza vaccine manufacturing is based on using chicken eggs. However, the necessity of the availability of millions of fertile eggs in the event of a pandemic has led research to focus on the development of cell culture-derived vaccines, which offer shorter lead-in times and greater flexibility of production. So far, the cell substrates being evaluated and in use include Vero, Madin-Darby canine kidney, PER.C6 and insect cells. However, Vero cells are the most widely accepted among others. This review introduces briefly the concepts of advanced cell culture-derived influenza vaccine production and highlights the advantages of these vaccines in terms of efficiency, speed and immunogenicity based on the clinical data obtained from different studies.

H1N1-infected Patients in ICU and Their Clinical Outcome

Background:

The swine flu (H1N1) with rapid spread and panic in population is truly global pandemic, affected mainly younger population. There is need to accumulate evidence regarding patient's intensive care parameters for effective management of newer strains of influenza viral infections. Hence an observed retrospective record analysis of confirmed H1N1 patients admitted to intensive care unit (ICU) of a tertiary care centre is done.

Aims:

The study was designed to study the profile and pattern of H1N1 patients admitted to ICU and to study the distribution and associated factors with treatment outcomes.

Materials and Methods:

The demographic, clinical, and laboratory data of 32 (RT-PCR confirmed) H1N1cases were collected and analyzed using Fischer's exact test/paired t test between survivors and nonsurvivors to know their significance. This data included criteria for admission to ICU, type of lung injury, mode of oxygenation, antiviral, and other drugs used.

Results:

There were 11 males and 21 female. Age ranged from 19 to 72 years. Age group of 15–45 years had most cases (78%) and mortality (60%). Most common symptoms were fever and breathlessness (100%). The mean duration of breathlessness was statistically significant (P = 0.037) between two groups. Most common signs were tachycardia and tachypnea. The 75% cases developed acute respiratory distress syndrome (ARDS), of this 16% survived. Among these fatal cases nine were positive for procalcitonin (PCT) (P = 0.006). The rest of 25% developed acute lung injury (ALI) and recovered completely (P = 0.0001).

Conclusion:

Fever and breathlessness were the main presenting complaints. Tachypnea and tachycardia as clinical signs predict development of respiratory complications. Arterial blood gas analysis (ABG) and PaO₂/FiO₂ were important in deciding severity of lung injury and mode of ventilation. ARDS was observed to be the main cause of mortality in this study. Serum PCT level estimation is useful in determining outcome.

"Trivalent influenza vaccination of healthy adults 3 years after the onset of swine-origin H1N1 pandemic: restricted immunogenicity of the new A/H1N1v constituent?"

Influenza vaccination is advised annually to reduce the burden of influenza disease. For sufficient vaccine campaigns also a continuous adoption of influenza vaccines are necessary, due to particularly high genetic variability of influenza A virus. Therefore, we evaluate the effectiveness of the trivalent influenza vaccine 2010/2011, against influenza A (H1N1, H3N2) and influenza B. Immune response was investigated in paired sera from 92 healthcare workers with the hemagglutination inhibition assay (HI). Protective antibody levels (HI titer ≥40) were found after vaccination for influenza A/California/07/2009(H1N1): 84.71 % [GMT: 115.34]; for influenza A/Perth/16/2009(H3N2): 94.94 % [GMT: 268.47] and for influenza B/Brisbane/60/2008: 96.20 % [GMT: 176.83]; matching with the currently circulating virus strains. However, the highest seroprevalence rate was found against influenza B; pre- and post-vaccination titers as well, which may be due to comparatively high virus preservation. Remarkable, lowest seropositivity was seen against H1N1. Despite the significant titer rise, sufficient H1N1 herd immunity was still not achieved. It can be assumed that a high influenza A herd immunity may be a requirement for a successful booster vaccination.

H1N1v at a seroepidemiological glance: is the nightmare over?

When the second wave of pandemic influenza A H1N1v 2009 (H1N1v) emerged in the winter of 2010/2011, public health authorities were afraid of dangerous implications and severe clinical courses again. As further H1N1v waves might appear, achievement of sufficient herd immunity is a matter of urgency. The objective of this study was to determine the seroprevalence of antibodies against H1N1v by hemagglutination-inhibition test (HI) after the second wave. We compared our recent findings with our data obtained after the first pandemic in 2009/2010. Between March and May 2011 we collected serum samples from 600 persons aged 1 to 84 years admitted to University Hospital Frankfurt/Main and analysed the titres of anti-H1N1v by HI. The overall seroprevalence of anti-H1N1v has risen from 36.9% (95% confidence interval (95%CI), 33-41) in unvaccinated persons after the first wave to 57.3% (95%CI, 53.1-61.2) in vaccinated and unvaccinated. The highest rate of seropositivity was detected in the age group of 10-19 years (66%; 95%CI, 55.8-75.2), whereas the lowest was found in the age group 40-59 years (51%; 95%CI, 40.8-61.1). Although seroprevalence has significantly increased, sufficient herd immunity is still not achieved. Therefore, general vaccination programs have to be propagated continuously by public health authorities.

Avian influenza A virus PB2 promotes interferon type I inducing properties of a swine strain in porcine dendritic cells

The 2009 influenza A virus (IAV) pandemic resulted from reassortment of avian, human and swine strains probably in pigs. To elucidate the role of viral genes in host adaptation regarding innate immune responses, we focussed on the effect of genes from an avian H5N1 and a porcine H1N1 IAV on infectivity and activation of porcine GM-CSF-induced dendritic cells (DC). The highest interferon type I responses were achieved by the porcine virus reassortant containing the avian polymerase gene PB2. This finding was not due to differential tropism since all viruses infected DC equally. All viruses equally induced MHC class II, but porcine H1N1 expressing the avian viral PB2 induced more prominent nuclear NF-κB translocation compared to its parent IAV. The enhanced activation of DC may be detrimental or beneficial. An over-stimulation of innate responses could result in either pronounced tissue damage or increased resistance against IAV reassortants carrying avian PB2.

Recent publications in medical microbiology and immunology: a retrospective

A look back is done to some clinical and basic research activities recently published in medical microbiology and immunology. The review covers clinical experiences and in vitro experiments to understand the emergency, pathogenicity, epidemic spread, and vaccine-based prevention of avian and swine-origin flu. Some new developments and concepts in diagnosis, (molecular) epidemiology, and therapy of AIDS, viral hepatitis C, and herpesvirus-associated diseases are outlined. Regulation of immune system has been discussed in a special issue 2010 including some aspects of CNS affections (measles). Mycobacterial infection and its prevention by modern recombinant vaccines have reached new interest, as well as new concepts of vaccination and prophylaxis against several other bacteria. Adaptation to host niches enables immune escape (example brucella) and determines virulence (example N. meningitidis). Chlamydia pneumoniae, previously considered to trigger atherosclerosis, is hypothetically associated to Alzheimer disease, while CMV, another putative trigger of atherosclerosis, gains evidence of oncomodulation in CNS tumor diseases. In terms of globalization, exotic virus infections are increasingly imported from southern countries.

Neuraminidase inhibitor susceptibility of swine influenza A viruses isolated in Germany between 1981 and 2008

European swine influenza A viruses donated the matrix protein 2 as well as the neuraminidase (NA) gene to pandemic influenza A (H1N1) viruses that emerged in 2009. As a result, the latter became amantadine resistant and neuraminidase inhibitor (NAI) susceptible. These recent developments reflecting the close connection between influenza A virus infection chains in humans and pigs urge an antiviral surveillance within swine influenza A viruses. Here, NAI susceptibility of 204 serologically typed swine influenza A viruses of subtypes H1N1, H1N2, and H3N2 circulating in Germany between 1981 and 2008 was analyzed in chemiluminescence-based NA inhibition assays. Mean 50% inhibitory concentrations of oseltamivir and zanamivir indicate a good drug susceptibility of tested viruses. As found for human isolates, the oseltamivir and zanamivir susceptibility was subtype-specific. So, swine influenza A (H1N1) viruses were just as susceptible to oseltamivir as to zanamivir. In contrast, swine H1N2 and H3N2 influenza A viruses were more sensitive to oseltamivir than to zanamivir. Furthermore, reduction in plaque size and virus spread by both drugs was tested with selected H1N1 and H1N2 isolates in MDCK cells expressing similar amounts of α2.3- and α2.6-linked sialic acid receptors. Data obtained in cell culture-based assays for H1N1 isolates correlated with that from enzyme inhibition assays. But, H1N2 isolates that are additionally glycosylated at Asn158 and Asn163 near the receptor-binding site of hemagglutinin (HA) were resistant to both NAI in MDCK cells. Possibly, these additional HA glycosylations cause a misbalance between HA and NA function that hampers or abolishes NAI activity in cells.

Pandemic Influenza Detection by Electrically Active Magnetic Nanoparticles and Surface Plasmon Resonance

Influenza A virus (FLUAV), the causative agent of influenza infection, has received extensive attention due to the recent swine-origin H1N1 pandemic. FLUAV has long been the cause of annual epidemics as well as less frequent but more severe global pandemics. Here, we describe a biosensor utilizing electrically active magnetic (EAM) polyaniline-coated nanoparticles as the transducer in an electrochemical biosensor for rapidly identifying FLUAV strains based on receptor specificity, which will be useful to monitor animal influenza infections and to characterize pandemic potential of strains that have transmitted from animals to humans. Pandemic potential requires human-to-human transmissibility, which is dependent upon FLUAV hemagglutinin (HA) specificity for host glycan receptors. Avian FLUAV preferentially bind to α2,3-linked receptors, while human FLUAV bind to α2,6-linked receptors. EAM nanoparticles were prepared by synthesizing aniline monomer around gamma iron (III) oxide (γ-Fe₂O₃) cores, yielding 25-100-nm diameter nanoparticles that were structurally characterized by transmission electron microscopy and electron diffraction. The EAM nanoparticles were coated with monoclonal antibodies specific to H5N1 (A/Vietnam/1203/04). Specificity of binding between glycans and H5 was demonstrated. The biosensor results were correlative to supporting data from a surface plasmon resonance assay that characterized HA/glycan binding and α-H5 antibody activity. This novel study applies EAM nanoparticles as the transducer in a specific, portable, easy-to-use biosensor with great potential for disease monitoring and biosecurity applications.

The first identified case of pandemic H1N1 influenza in pigs in Australia

A 300-sow farrow-to-finish herd in New South Wales was infected with influenza pandemic (H1N1) 2009 (H1N1/09) virus in July 2009 and became the first recorded case of influenza in pigs in Australia. The outbreak resulted from human-to-pig transmission. Clinical signs in affected pigs were mild compared with overseas reports of 'classical' swine influenza virus and included coughing and decreased appetite in a small proportion of non-lactating breeding stock, weaners, growers and finishers. A diagnosis of H1N1/09 influenza virus infection was confirmed using a combination of serology (haemagglutination inhibition, blocking enzyme-linked immunosorbent assay) and real-time reverse transcription polymerase chain reaction. Attempts at virus isolation were unsuccessful. Results of a longitudinal study of pigs on this farm suggested that the virus continued to circulate for 9 weeks after the onset of infection, but was not present 6 months later. This report highlights the difficulties in preventing transmission of H1N1/09 influenza virus from infected humans to pigs during a human pandemic.

Conserved host response to highly pathogenic avian influenza virus infection in human cell culture, mouse and macaque model systems

Background

Understanding host response to influenza virus infection will facilitate development of better diagnoses and therapeutic interventions. Several different experimental models have been used as a proxy for human infection, including cell cultures derived from human cells, mice, and non-human primates. Each of these systems has been studied extensively in isolation, but little effort has been directed toward systematically characterizing the conservation of host response on a global level beyond known immune signaling cascades.

Results

In the present study, we employed a multivariate modeling approach to characterize and compare the transcriptional regulatory networks between these three model systems after infection with a highly pathogenic avian influenza virus of the H5N1 subtype. Using this approach we identified functions and pathways that display similar behavior and/or regulation including the well-studied impact on the interferon response and the inflammasome. Our results also suggest a primary response role for airway epithelial cells in initiating hypercytokinemia, which is thought to contribute to the pathogenesis of H5N1 viruses. We further demonstrate that we can use a transcriptional regulatory model from the human cell culture data to make highly accurate predictions about the behavior of important components of the innate immune system in tissues from whole organisms.

Conclusions

This is the first demonstration of a global regulatory network modeling conserved host response between in vitro and in vivo models.

Applications of the phytomedicine Echinacea purpurea (Purple Coneflower) in infectious diseases

Extracts of Echinacea purpurea (EP, purple coneflower) have been used traditionally in North America for the treatment of various types of infections and wounds, and they have become very popular herbal medicines globally. Recent studies have revealed that certain standardized preparations contain potent and selective antiviral and antimicrobial activities. In addition, they display multiple immune-modulatory activities, comprising stimulation of certain immune functions such as phagocytic activity of macrophages and suppression of the proinflammatory responses of epithelial cells to viruses and bacteria, which are manifested as alterations in secretion of various cytokines and chemokines. These immune modulations result from upregulation or downregulation of the relevant genes and their transcription factors. All these bioactivities can be demonstrated at noncytotoxic concentrations of extract and appear to be due to multiple components rather than the individual chemical compounds that characterize Echinacea extracts. Potential applications of the bioactive extracts may go beyond their traditional uses.

Negative regulation of lung inflammation and immunopathology by TNF-α during acute influenza infection

Lung immunopathology is the main cause of influenza-mediated morbidity and death, and much of its molecular mechanisms remain unclear. Whereas tumor necrosis factor-α (TNF-α) is traditionally considered a proinflammatory cytokine, its role in influenza immunopathology is unresolved. We have investigated this issue by using a model of acute H1N1 influenza infection established in wild-type and TNF-α-deficient mice and evaluated lung viral clearance, inflammatory responses, and immunopathology. Whereas TNF-α was up-regulated in the lung after influenza infection, it was not required for normal influenza viral clearance. However, TNF-α deficiency led not only to a greater extent of illness but also to heightened lung immunopathology and tissue remodeling. The severe lung immunopathology was associated with increased inflammatory cell infiltration, anti-influenza adaptive immune responses, and expression of cytokines such as monocyte chemoattractant protein-1 (MCP-1) and fibrotic growth factor, TGF-β1. Thus, in vivo neutralization of MCP-1 markedly attenuated lung immunopathology and blunted TGF-β1 production following influenza infection in these hosts. On the other hand, in vivo transgenic expression of MCP-1 worsened lung immunopathology following influenza infection in wild-type hosts. Thus, TNF-α is dispensable for influenza clearance; however, different from the traditional belief, this cytokine is critically required for negatively regulating the extent of lung immunopathology during acute influenza infection.

Perceptions Regarding Influenza Vaccination during Pregnancy among Childbearing Women

PURPOSE

The purpose of this study was to examine womens' perceptions regarding influenza vaccination during pregnancy among Korean childbearing women.

METHODS

Data was collected using focus group interviews from June to September, 2010. Forty Korean women participated in 13 focus groups. After obtaining permission from participants, each session of the focus group was audio-taped and transcribed verbatim. The responses were analyzed utilizing qualitative content analysis.

RESULTS

Forty women ranging from 26 to 43 participated in the study. The major themes were safety concerns; effects of fetal protection and infection prevention; lack of perceived needs; and encouragement as well as concerns from others. Participants raised questions on whether the vaccine was safe and effective, and concerns about the potential harmful effect of influenza vaccine to their bodies and the fetus. The major reason for influenza vaccination during pregnancy was to protect self and fetus. Also, clinician's recommendation was the facilitating factors for influenza vaccination during pregnancy.

CONCLUSION

The findings suggest that concerns associated with influenza vaccination should be considered when educating childbearing women about the influenza vaccine during pregnancy.

An equine herpesvirus 1 (EHV-1) vectored H1 vaccine protects against challenge with swine-origin influenza virus H1N1

In 2009, a novel swine-origin H1N1 influenza A virus (S-OIV), antigenically and genetically divergent from seasonal H1N1, caused a flu pandemic in humans. Development of an effective vaccine to limit transmission of S-OIV in animal reservoir hosts and from reservoir hosts to humans and animals is necessary. In the present study, we constructed and evaluated a vectored vaccine expressing the H1 hemagglutinin of a recent S-OIV isolate using equine herpesvirus 1 (EHV-1) as the delivery vehicle. Expression of the recombinant protein was demonstrated by immunofluorescence and western blotting and the in vitro growth properties of the modified live vector were found to be comparable to those of the parental virus. The EHV-1-H1 vaccine induced an influenza virus-specific antibody response when inoculated into mice by both the intranasal and subcutaneous routes. Upon challenge infection, protection of vaccinated mice could be demonstrated by reduction of clinical signs and faster virus clearance. Our study shows that an EHV-1-based influenza H1N1 vaccine may be a promising alternative for protection against S-OIV infection.

Fitting evolutionary process of influenza A virus nucleoproteins using analytical solution of system of differential equations

Very recently we explored the possibility of using differential equations to describe the evolution of proteins. In this study we used the amino-acid pair predictability to quantify 1709 nucleoproteins of influenza A viruses isolated from 1918 to 2008 to represent their evolutionary process, thereafter we used the analytical solution of system of differential equations to fit the evolution of the nucleoprotein family. The results showed that the analytical solution could fit the nucleoprotein evolution and the obtained parameters were useful for timing of future mutations. Our approach provided a way to quantitatively analyze protein dynamics and evolution.