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We propose a sensitive H1N1 virus fluorescence biosensor based on ligation-transcription and CRISPR/Cas13a-assisted cascade amplification strategies. Products are generated via the hybridization of single-stranded DNA (ssDNA) probes containing T7 promoter and crRNA templates to a target RNA sequence using SplintR ligase. This generates large crRNA quantities in the presence of T7 RNA polymerase. At such crRNA quantities, ternary Cas13a, crRNA, and activator complexes are successfully constructed and activate Cas13a to enhance fluorescence signal outputs. The biosensor sensitively and specifically monitored H1N1 viral RNA levels down to 3.23 pM and showed good linearity when H1N1 RNA concentrations were 100 pM–1 µM. Biosensor specificity was also excellent. Importantly, our biosensor may be used to detect other viral RNAs by altering the sequences of the two probe junctions, with potential applications for the clinical diagnosis of viruses and other biomedical studies. [ABSTRACT FROM AUTHOR]

The use of copper as an antimicrobial agent has a long history and has gained renewed interest in the context of the COVID-19 pandemic. In this study, the authors investigated the antimicrobial properties of an alloy composed of copper with a small percentage of silver (Cu-0.03% wt.Ag). The alloy was tested against various pathogens, including Escherichia coli, Staphylococcus aureus, Candida albicans, Pseudomonas aeruginosa, and the H1N1 virus, using contact exposure tests. Results showed that the alloy was capable of inactivating these pathogens in two hours or less, indicating its strong antimicrobial activity. Electrochemical measurements were also performed, revealing that the small addition of silver to copper promoted a higher resistance to corrosion and shifted the formation of copper ions to higher potentials. This shift led to a slow but continuous release of Cu2+ ions, which have high biocidal activity. These findings show that the addition of small amounts of silver to copper can enhance its biocidal properties and improve its effectiveness as an antimicrobial material. [ABSTRACT FROM AUTHOR]

Abstract Background Rosmarinic acid (RosA) is a natural phenolic compound that possesses a wide-range of pharmacological properties. However, the effects of RosA on influenza A virus-mediated acute lung injury remain unknown. In this study, we aimed to explore whether RosA could protect against H1N1 virus-mediated lung injury and elucidate the underlying mechanisms. Methods Mice were intragastrically administered with RosA for 2 days before intranasal inoculation of the H1N1 virus (5LD50) for the establishment of an acute lung injury model. At day 7 post-infection (p.i.), gross anatomic lung pathology, lung histopathologic, and lung index (lung weight/body weight) were examined. Luminex assay, multiple immunofluorescence and flow cytometry were performed to detect the levels of pro-inflammatory cytokines and apoptosis, respectively. Western blotting and plasmid transfection with hematopoietic-type PGD2 synthase (h-PGDS) overexpression were conducted to elucidate the mechanisms. Results RosA effectively attenuated H1N1 virus-triggered deterioration of gross anatomical morphology, worsened lung histopathology, and elevated lung index. Excessive pro-inflammatory reactions, aberrant alveolar epithelial cell apoptosis, and cytotoxic CD8+ T lung recruitment in the lung tissues induced by H1N1 virus infection were observed to be reduced by RosA treatment. In vitro experiments demonstrated that RosA treatment dose-dependently suppressed the increased levels of pro-inflammatory mediators and apoptosis through inhibition of nuclear factor kappa B (NF-κB) and P38 MAPK signaling pathways in H1N1 virus-infected A549 cells, which was accompanied by promoting activation of the h-PGDS-PGD2-HO-1 signal axis. Furthermore, we strikingly found that h-PGDS inhibition significantly abrogated the inhibitory effects of RosA on H1N1 virus-mediated activation of NF-κB and P38 MAPK signaling pathways, resulting in diminishing the suppressive effects on the increased levels of pro-inflammatory cytokines and chemokines as well as apoptosis. Finally, suppressing h-PGDS prominently abolished the protective effects of RosA on H1N1 virus-mediated severe pneumonia and lung injury. Conclusions Taken together, our study demonstrates that RosA is a promising compound to alleviate H1N1 virus-induced severe lung injury through prompting the h-PGDS-PGD2-HO-1 signal axis.

Background: Rosmarinic acid (RosA) is a natural phenolic compound that possesses a wide-range of pharmacological properties. However, the effects of RosA on influenza A virus-mediated acute lung injury remain unknown. In this study, we aimed to explore whether RosA could protect against H1N1 virus-mediated lung injury and elucidate the underlying mechanisms. Methods: Mice were intragastrically administered with RosA for 2 days before intranasal inoculation of the H1N1 virus (5LD50) for the establishment of an acute lung injury model. At day 7 post-infection (p.i.), gross anatomic lung pathology, lung histopathologic, and lung index (lung weight/body weight) were examined. Luminex assay, multiple immunofluorescence and flow cytometry were performed to detect the levels of pro-inflammatory cytokines and apoptosis, respectively. Western blotting and plasmid transfection with hematopoietic-type PGD2 synthase (h-PGDS) overexpression were conducted to elucidate the mechanisms. Results: RosA effectively attenuated H1N1 virus-triggered deterioration of gross anatomical morphology, worsened lung histopathology, and elevated lung index. Excessive pro-inflammatory reactions, aberrant alveolar epithelial cell apoptosis, and cytotoxic CD8+ T lung recruitment in the lung tissues induced by H1N1 virus infection were observed to be reduced by RosA treatment. In vitro experiments demonstrated that RosA treatment dose-dependently suppressed the increased levels of pro-inflammatory mediators and apoptosis through inhibition of nuclear factor kappa B (NF-κB) and P38 MAPK signaling pathways in H1N1 virus-infected A549 cells, which was accompanied by promoting activation of the h-PGDS-PGD2-HO-1 signal axis. Furthermore, we strikingly found that h-PGDS inhibition significantly abrogated the inhibitory effects of RosA on H1N1 virus-mediated activation of NF-κB and P38 MAPK signaling pathways, resulting in diminishing the suppressive effects on the increased levels of pro-inflammatory cytokines and chemokines as well as apoptosis. Finally, suppressing h-PGDS prominently abolished the protective effects of RosA on H1N1 virus-mediated severe pneumonia and lung injury. Conclusions: Taken together, our study demonstrates that RosA is a promising compound to alleviate H1N1 virus-induced severe lung injury through prompting the h-PGDS-PGD2-HO-1 signal axis. [ABSTRACT FROM AUTHOR]

This study aims to screen and identify specific cluster miRNAs of H7N9 virus-infected N2a cells and explore the possible pathogenesis of these miRNAs. The N2a cells are infected with H7N9 and H1N1 influenza viruses, and the cells are collected at 12, 24 and 48 h to extract total RNA. To sequence miRNAs and identify different virus-specific miRNAs, high-throughput sequencing technology is used. Fifteen H7N9 virus-specific cluster miRNAs are screened, and eight of them are included in the miRBase database. These cluster-specific miRNAs regulate many signaling pathways, such as the PI3K-Akt signaling pathway, the RAS signaling pathway, the cAMP signaling pathway, actin cytoskeleton regulation and cancer-related genes. The study provides a scientific basis for the pathogenesis of H7N9 avian influenza, which is regulated by miRNAs. [ABSTRACT FROM AUTHOR]

Objective(s): Influenza A virus (IAV) is a contagious illness. Different species of Scutellaria genus are used as a traditional remedy to reduce influenza symptoms. This study aimed to investigate the anti-influenza capacity of several species of Iranian Scutellaria and identify active compounds of the most potent species for the first time.Materials and Methods: Some Iranian species of Scutellaria were collected from different regions of Iran, including S. pinnatifida with mucida, viridis, and alpina subspecies; S. tournefortii; S. tomentosa; S. persica. They were fractionated to chloroform and methanol. The total phenols and flavonoids of samples were examined by the folin-ciocalteau and aluminum-flavonoid complex methods, respectively. The 50% cytotoxic concentrations (CC50) on MDCK cells and non-cytotoxic concentrations (NCTC) were determined by MTT assay. The percentage of cell protection against IAV and their effect on virus titer were investigated in pre-, post-, and co-penetration treatment groups. Phytochemicals of the most effective species were isolated by various chromatographic methods and identified by different spectroscopic methods.Results: Methanol fraction of S. pinnatifida subsp. viridis demonstrated the highest amounts of flavonoid content and best activity against influenza A virus in all combination treatments, which reduced the virus titer by 5 logs with no cytotoxicity. Kaempferol-3-O-glucoside, quercetin-3-O-glucoside, apigenin-4′-methoxy-7-O-glucoside, luteolin, and luteolin-7-O-glucoside were purified and identified from this species.Conclusion: Scutellaria pinnatifida subsp. viridis can be introduced as a source of flavonoids with acceptable anti-influenza activity. S. tomentosa also showed potent antiviral effects and is a candidate for elucidation in further studies.

Objective: To Identify molecular characterization of swine flu (H1N1) pdm 09 and seasonal flu (influenza A). Materials and methods: NP/OP Swab specimen of 142 patients were collected aseptically in VTM. Nucleic Acid was extracted manually and was processed in Real-Time PCR for identification of swine flu (H1N1) 09 pdm and seasonal flu (inf A). Results: In this study, 142 patients presented with signs and symptoms of Flu like illness patients and were tested by Real-time PCR. Out of total 32 (22.53%) positive specimens, 18(56.25%) were positive swine flu(H1N1) 09 pdm and 14(43.73%) were positive seasonal flu (inf A). Conclusion: We report a tiny outbreak of 18 swine flu (H1N1) 09 pdm and 14 seasonal flu cases in our hospital, from Jan 2022 to June 2022. The outbreak involved persons of all age groups, but it mostly affected paediatric age group.

To cope with the easy transmissibility of the avian influenza A virus subtype H1N1, a biosensor was developed for rapid and highly sensitive electrochemical immunoassay. Based on the principle of specific binding between antibody and virus molecules, the active molecule-antibody-adapter structure was formed on the surface of an Au NP substrate electrode; it included a highly specific surface area and good electrochemical activity for selective amplification detection of the H1N1 virus. The electrochemical test results showed that the BSA/H1N1 Ab/Glu/Cys/Au NPs/CP electrode was used for the electrochemical detection of the H1N1 virus with a sensitivity of 92.1 µA (pg/mL)−1 cm2, LOD of 0.25 pg/ml, linear ranges of 0.25–5 pg/mL, and linearity of (R2 = 0.9846). A convenient H1N1 antibody-based electrochemical electrode for the molecular detection of the H1N1 virus will be of great use in the field of epidemic prevention and raw poultry protection. [ABSTRACT FROM AUTHOR]

The use of copper as an antimicrobial agent has a long history and has gained renewed interest in the context of the COVID-19 pandemic. In this study, the authors investigated the antimicrobial properties of an alloy composed of copper with a small percentage of silver (Cu-0.03% wt.Ag). The alloy was tested against various pathogens, including Escherichia coli, Staphylococcus aureus, Candida albicans, Pseudomonas aeruginosa, and the H1N1 virus, using contact exposure tests. Results showed that the alloy was capable of inactivating these pathogens in two hours or less, indicating its strong antimicrobial activity. Electrochemical measurements were also performed, revealing that the small addition of silver to copper promoted a higher resistance to corrosion and shifted the formation of copper ions to higher potentials. This shift led to a slow but continuous release of Cu2+ ions, which have high biocidal activity. These findings show that the addition of small amounts of silver to copper can enhance its biocidal properties and improve its effectiveness as an antimicrobial material.

H1N1 is a kind of influenza A virus that causes serious health issues throughout the world. Its symptoms are more serious than seasonal flu and can sometimes be lethal. For this reason, rapid, accurate, and effective diagnostic tests are needed. In this study, an electrochemical immunosensor for the sensitive, selective, and practical detection of the H1N1 virus was developed. The sensor platform included multi-walled carbon nanotube gold-platinum (MWCNT-Au-Pt) hybrid nanomaterial and anti-hemagglutinin (anti-H1) monoclonal antibody. For the construction of this biosensor, a gold screen-printed electrode (AuSPE) was used as a transducer. Firstly, AuSPE was modified with MWCNT-Au-Pt hybrid nanomaterial via drop casting. Anti-H1 antibody was immobilized onto the electrode surface after the modification process with cysteamine was applied. Then, the effect of the interaction time with cysteamine for surface modification was investigated. Following that, the experimental parameters, such as the amount of hybrid nanomaterial and the concentration of anti-H1 were optimized. Under the optimized conditions, the analytical characteristics of the developed electrochemical immunosensor were investigated for the H1N1 virus by using electrochemical impedance spectroscopy. As a result, a linear range was obtained between 2.5–25.0 µg/mL with a limit of the detection value of 3.54 µg/mL. The relative standard deviation value for 20 µg/mL of the H1N1 virus was also calculated and found as 0.45% (n = 3). In order to determine the selectivity of the developed anti-H1-based electrochemical influenza A immunosensor, the response of this system towards the H3N2 virus was investigated. The matrix effect was also investigated by using synthetic saliva supplemented with H1N1 virus. [ABSTRACT FROM AUTHOR]

Viral-host protein-protein interaction (VHPPI) prediction is essential to decoding molecular mechanisms of viral pathogens and host immunity processes that eventually help to control the propagation of viral diseases and to design optimized therapeutics. Multiple AI-based predictors have been developed to predict diverse VHPPIs across a wide range of viruses and hosts, however, these predictors produce better performance only for specific types of hosts and viruses. The prime objective of this research is to develop a robust meta predictor (MP-VHPPI) capable of more accurately predicting VHPPI across multiple hosts and viruses. The proposed meta predictor makes use of two well-known encoding methods Amphiphilic Pseudo-Amino Acid Composition (APAAC) and Quasi-sequence (QS) Order that capture amino acids sequence order and distributional information to most effectively generate the numerical representation of complete viral-host raw protein sequences. Feature agglomeration method is utilized to transform the original feature space into a more informative feature space. Random forest (RF) and Extra tree (ET) classifiers are trained on optimized feature space of both APAAC and QS order separate encoders and by combining both encodings. Further predictions of both classifiers are utilized to feed the Support Vector Machine (SVM) classifier that makes final predictions. The proposed meta predictor is evaluated over 7 different benchmark datasets, where it outperforms existing VHPPI predictors with an average performance of 3.07, 6.07, 2.95, and 2.85% in terms of accuracy, Mathews correlation coefficient, precision, and sensitivity, respectively. To facilitate the scientific community, the MP-VHPPI web server is available at https://sds_genetic_analysis.opendfki.de/MP-VHPPI/.

In this work, a synthetic approach to prepare an example of new class of the derivatives of the closo-decaborate anion with amino acids detached from the boron cluster by pendant group has been proposed and implemented. Compound Na2[B10H9–O(CH2)4C(O)–His–OMe] was isolated and characterized. This compound has an inorganic hydrophobic core which is the 10-vertex boron cage and the –O(CH2)4C(O)–His–OMe organic substituent. It has been shown to possess strong antiviral activity in vitro against modern strains of A/H1N1 virus at 10 and 5 µg/mL. The compound has been found to be non-cytotoxic up to 160 µg/mL. At the same time, the compound has been found to be inactive against SARS-CoV-2, indicating specific activity against RNA virus replication. Molecular docking of the target derivative of the closo-decaborate anion with a model of the transmembrane region of the M2 protein has been performed and the mechanism of its antiviral action is discussed. [ABSTRACT FROM AUTHOR]

Influenza virus-caused lung infection and its pandemic outbreaks are a persistent public health challenge. The H1N1 subtype is the most common type of influenza infection observed in humans. Maxingshigantang decoction, a classic formula of Chinese herbal medicine, has been used for the prevention and treatment of respiratory infection for many centuries. Qingfeiyin decoction, based on Maxingshigantang, has been used in the clinic for decades. To explore the underlying mechanisms, according to the traditional Chinese medicine theory "the lung and the large intestine are interior–exterior," which can be translated to the "gut–lung axis" in a contemporary term, the composition of gut microbiota was determined using 16S rRNA and the transcriptome of the colon was determined by RNA sequencing. The results showed that Qingfeiyin decoction decreased the viral load, alleviated the lung injury, increased the survival rate, partly restored the shortening of the colon caused by the H1N1 virus, and downregulated inflammatory pathways including MAPK, TNFα, and JAK-STAT signaling pathways. Qingfeiyin decoction increased the relative abundance of the genera of Coprococcus , Ruminococcus, Lactobacillus , and Prevotella and prevented the H1N1 virus-induced decrease in the abundance of the genera of Escherichia , Parabacteroides , Butyricimonas, and Anacrotruncus. These results will help better understand the mechanisms for Qingfeiyin decoction's protective effect against influenza virus infection. [ABSTRACT FROM AUTHOR]

Background and Aims: Nonstructural (NS1) protein is mainly involved in virulence and replication of several viruses, including influenza virus A (H1N1); surveillance of the latter started in India in 2009. The objective of this study was to identify the new substitutions in NS1 protein from the influenza virus A (H1N1) pandemic 2009 (pdm09) strain isolated in India. Methods: The sequences of NS1 proteins from influenza A(H1N1) pdm09 strains isolated in India were obtained from publicly available databases. Multiple sequence alignment and phylogeny analyses were performed to confirm the "consistent substitutions" on NS1 protein from H1N1 (pdm09) Indian strains. Here, "consistent substitutions" were defined as the substitutions observed in all the sequences isolated in a year. Comparative analyses were performed among NS1 Indian sequences from A(H1N1) pdm09, A (H1N1) seasonal and A(H3N2) strains, and from A (H1N1) pdm09 global strains. Results: Eight substitutions were identified in the NS1 Indian sequence from the A(H1N1) pdm09 strain, two in RBD, five in ED, and one in the linker region. Three new substitutions were reported in this study at NS1 sequence positions 2, 80, and 155, which evolved within 2015–2019 and became "consistent." These new substitutions were associated with conservative paired substitutions in the alternative domains of the NS1 protein. Three paired substitutions were (i) D2E and E125D, (ii) T80A and A155T, and (iii) E55K and K131E. Conclusions: This study indicates the continuous evolution of NS1 protein from the influenza A virus. The new substitutions at positions 2 and 80 occurred in the RNA binding and eIF4GI binding domains. The D2E substitution evolved simultaneously with the E125D substitution that involved viral replication. The third new substitution at position 155 occurred in the PI3K binding domain. The possible consequences of these substitutions on host–pathogen interactions are subject to further experimental and computational verification. [ABSTRACT FROM AUTHOR]

Carbon nano onion (CNO) from dried grass has been synthesized by carbonization in the size range, 20 to 100 nm. This shows catalytic property to transform aerial oxygen under visible light to generate reactive oxygen species (ROS). A concept has been presented herein to show that this CNO even under room light generates hydrogen peroxide which inhibits WSN influenza virus (H1N1). The advantage of introducing CNO, synthesized from a cheap source to cater to the global need, is to sterilize infected hospitals indoor and outdoor, aircraft carriers, air conditioner vents due to its sustained conversion of air to ROS. Thus, CNO use could prevent frequent evacuation as used by conventional sanitisers to sterilize infected places from other RNA virus and hospital pathogens under COVID-19 pandemic. Carbon nano onion (CNO) under aerial oxygen on exposure with visible light generates ROS which is capable to rupture the lipid envelope of SARS-CoV-2 followed by disintegrating its RNA. [ABSTRACT FROM AUTHOR]

Influenza virus-caused lung infection and its pandemic outbreaks are a persistent public health challenge. The H1N1 subtype is the most common type of influenza infection observed in humans. Maxingshigantang decoction, a classic formula of Chinese herbal medicine, has been used for the prevention and treatment of respiratory infection for many centuries. Qingfeiyin decoction, based on Maxingshigantang, has been used in the clinic for decades. To explore the underlying mechanisms, according to the traditional Chinese medicine theory “the lung and the large intestine are interior–exterior,” which can be translated to the “gut–lung axis” in a contemporary term, the composition of gut microbiota was determined using 16S rRNA and the transcriptome of the colon was determined by RNA sequencing. The results showed that Qingfeiyin decoction decreased the viral load, alleviated the lung injury, increased the survival rate, partly restored the shortening of the colon caused by the H1N1 virus, and downregulated inflammatory pathways including MAPK, TNFα, and JAK-STAT signaling pathways. Qingfeiyin decoction increased the relative abundance of the genera of Coprococcus, Ruminococcus, Lactobacillus, and Prevotella and prevented the H1N1 virus-induced decrease in the abundance of the genera of Escherichia, Parabacteroides, Butyricimonas, and Anacrotruncus. These results will help better understand the mechanisms for Qingfeiyin decoction’s protective effect against influenza virus infection.

Background: Emerging pandemic viruses may have multiple deleterious effects on maternal health. This study examines the effects of a pandemic influenza virus on cause-specific maternal mortality time series, using Argentinian vital statistics. Methods: We conducted a population-based natural experiment from national vital records of maternal deaths between 1980 and 2017. Joinpoint regression models were used to model time series of the maternal mortality ratio (MMR). The sensitivity of the registry to detect the effects of the pandemic H1N1 2009 influenza virus on cause-specific MMR was analysed using a panel of parallel interrupted time series (ITS). Findings: Over this 38-year study, the MMR decreased by 58·6% (69·5 to 28·8 deaths/100,000 live births), transitioning from direct obstetric causes (67·0 to 21·1/100,000 live births; 68·4% decrease) to indirect causes (2·6 to 7·7/100,000 live births; 196·2% increase). The regression analysis showed an average reduction of -2·2%/year (95% CI: -2·9 to -1·4) with 2 join points in the total trend (1998 and 2009). Parallel ITS analyses revealed the pandemic H1N1 virus had an increasing effect on mortality from the respiratory system- and sepsis-related complications (level change 4·7 and 1·6/100,000 live births respectively), reversing after the outbreak. No effect was found on MMR from hypertensive disorders, haemorrhage, abortive outcomes, other direct obstetric causes, and indirect non-respiratory comorbidities. Interpretation: The Argentinian maternal death registry appears sensitive to detect different effects of emerging infectious epidemics on maternal health. In a population-based natural experiment, pandemic H1N1 virus impacted maternal mortality almost exclusively from the respiratory system- and sepsis-related complications. Funding: Supported by FISAR www.fisarchile.org

H1N1 is a kind of influenza A virus that causes serious health issues throughout the world. Its symptoms are more serious than seasonal flu and can sometimes be lethal. For this reason, rapid, accurate, and effective diagnostic tests are needed. In this study, an electrochemical immunosensor for the sensitive, selective, and practical detection of the H1N1 virus was developed. The sensor platform included multi-walled carbon nanotube gold-platinum (MWCNT-Au-Pt) hybrid nanomaterial and anti-hemagglutinin (anti-H1) monoclonal antibody. For the construction of this biosensor, a gold screen-printed electrode (AuSPE) was used as a transducer. Firstly, AuSPE was modified with MWCNT-Au-Pt hybrid nanomaterial via drop casting. Anti-H1 antibody was immobilized onto the electrode surface after the modification process with cysteamine was applied. Then, the effect of the interaction time with cysteamine for surface modification was investigated. Following that, the experimental parameters, such as the amount of hybrid nanomaterial and the concentration of anti-H1 were optimized. Under the optimized conditions, the analytical characteristics of the developed electrochemical immunosensor were investigated for the H1N1 virus by using electrochemical impedance spectroscopy. As a result, a linear range was obtained between 2.5–25.0 µg/mL with a limit of the detection value of 3.54 µg/mL. The relative standard deviation value for 20 µg/mL of the H1N1 virus was also calculated and found as 0.45% (n = 3). In order to determine the selectivity of the developed anti-H1-based electrochemical influenza A immunosensor, the response of this system towards the H3N2 virus was investigated. The matrix effect was also investigated by using synthetic saliva supplemented with H1N1 virus.

The H1N1 influenza virus causes a severe disease that affects the human respiratory tract leading to millions of deaths every year. At present, certain vaccines and few drugs are used to control the virus during seasonal outbreaks. However, high mutation rates and genetic reassortment make it challenging to prevent and mitigate outbreaks, leading to pandemics. Thus, alternate therapies are required for its management and control. Here, we report that a bacterial protein, azurin, and its peptide derivatives p18 and p28 target critical proteins of the influenza virus in an effective manner. The molecular docking studies show that the p28 peptide could target C-PB1, NS1-ED, PB2-CBD, PB2-RBD, NP, and PA proteins. These complexes were further subjected to the simulation of molecular dynamics and binding free energy calculations. The data indicate that p28 has an unusually high affinity and forms stable complexes with the viral proteins C-PB1, PB2-CBD, PB2-RBD, and NP. We suggest that the azurin derivative p28 peptide can act as an anti-influenza agent as it can bind to multiple targets and neutralize the virus. Additional experimental studies need to be conducted to evaluate its safety and efficacy as an anti-H1N1 molecule. [ABSTRACT FROM AUTHOR]

Cases of spontaneous pneumomediastinum and spontaneous pneumothorax related with influenza A (H1N1) infection in adults are quite rare. The case presented here was a 33-year old female patient admitted to the emergency room with high fever, severe dyspnea, cough and altered consciousness. Pneumomediastinum and bilateral pneumothorax were detected on a chest roentgenogram and thoracic computerized tomography imaging. The H1N1 virus was identified in a nasal smear and in tracheal aspirate samples. Clinicians should be aware of this rare complication of the Influenza A virus that has started to be seen in literature. [ABSTRACT FROM AUTHOR]

In Pakistan, the burden of influenza was largely unknown, as no formal surveillance system was in place. In 2008, an influenza surveillance system was set up in eight sentinel sites. This study describes the epidemiology of influenza virus using a 10‐year surveillance data from 2008 to 2017. Nasopharyngeal/throat swabs were collected from patients with influenza‐like illness (ILI) and severe acute respiratory illness (SARI) along with relevant epidemiological information. The samples were tested using real‐time reverse transcriptase‐polymerase chain reaction for the detection and characterization of influenza viruses. A total of 17 209 samples were tested for influenza, out of which 3552 (20.6%) were positive; 2151/11 239 (19.1%) were patients with ILI, whereas 1401/5970 (23.5%) were patients with SARI. Influenza A/H1N1pdm09 was the predominant strain with 40.6% (n = 1442) followed by influenza B (936, 26.4%). Influenza A/H1N1pdm09 was predominant among the children (5‐14 years) and adults (15‐64 years). Influenza B strain was predominantly found in the elderly age group (≥ 65 years) accounting for 48% of cases followed by children (2‐4 years) accounting for 37% of cases. This 10‐year surveillance data provides evidence of influenza activity in the country throughout the year with seasonal winter peaks. The results could be used to strengthen the epidemic preparedness and response plan. Highlights: The study findings allow national policy makers to better prepare for upcoming seasons.The study describes critical features of influenza epidemiology including risk groups and transmission characteristics.The study will support the selection of influenza strains for vaccine production.Influenza viruses affected all age groups and gender and circulated seasonally peaking during the winter months of December through February. [ABSTRACT FROM AUTHOR]

The H1N1 influenza virus is known as a serious pandemic threat across the globe. Vaccination is one of the most effective methods of protection against this virus and the way to reduce the seasonal pandemic risk. The commercial vaccine does not adequately respond to pandemic strains. This study examines the potential function of formulated H1N1 hemagglutinin with MF59 adjuvant against A/PR/8/34 (H1N1). To this end, a recombinant hemagglutinin (rHA) gene of influenza A virus was designed and expressed in SF9 cell by the Baculovirus expression system. Four groups of mice were immunized by rHA in combination with MF59, Alum adjuvant, and virus split only. The immunized mice subsequently used for the humoral immune assay and the results compared with untreated mice (negative group). Besides, both treated and control mice groups were challenged with mouse-adapted influenza virus A/PR/8/34(H1N1) through the intranasal drop. Bodyweight, survival, temperature variation, and the medical conditions of the samples were assessed. Mice immunized with the recombinant protein demonstrated a humoral response to the influenza A virus. Upon virus challenging, co-administration of rHA with MF59 adjuvant could lead to 92% survival of the vaccinated mice within 10 days. The MF59-treated group showed slight weight loss and high-temperature body two weeks after infection. This group also displayed a higher hemagglutination inhibition (HI) antibody titer as compared to the group vaccinated with virus split, and Alum adjuvant. Altogether, the results showed that the recombinant protein with the MF59 adjuvant created better safety than the Alum adjuvant, thereby can be considered as a safe and reliable vaccine against the H1N1 virus for further investigations.

The H1N1 influenza virus is known as a serious pandemic threat across the globe. Vaccination is one of the most effective methods of protection against this virus and the way to reduce the seasonal pandemic risk. The commercial vaccine does not adequately respond to pandemic strains. This study examines the potential function of formulated H1N1 hemagglutinin with MF59 adjuvant against A/PR/8/34 (H1N1). To this end, a recombinant hemagglutinin (rHA) gene of influenza A virus was designed and expressed in SF9 cell by the Baculovirus expression system. Four groups of mice were immunized by rHA in combination with MF59, Alum adjuvant, and virus split only. The immunized mice subsequently used for the humoral immune assay and the results compared with untreated mice (negative group). Besides, both treated and control mice groups were challenged with mouse-adapted influenza virus A/PR/8/34(H1N1) through the intranasal drop. Bodyweight, survival, temperature variation, and the medical conditions of the samples were assessed. Mice immunized with the recombinant protein demonstrated a humoral response to the influenza A virus. Upon virus challenging, co-administration of rHA with MF59 adjuvant could lead to 92% survival of the vaccinated mice within 10 days. The MF59-treated group showed slight weight loss and hightemperature body two weeks after infection. This group also displayed a higher hemagglutination inhibition (HI) antibody titer as compared to the group vaccinated with virus split, and Alum adjuvant. Altogether, the results showed that the recombinant protein with the MF59 adjuvant created better safety than the Alum adjuvant, thereby can be considered as a safe and reliable vaccine against the H1N1 virus for further investigations. [ABSTRACT FROM AUTHOR]

Seasonal influenza virus infections cause mild illness in healthy adults, as timely viral clearance is mediated by the functions of cytotoxic T cells. However, avian H5N1 influenza virus infections can result in prolonged and fatal illness across all age groups, which has been attributed to the overt and uncontrolled activation of host immune responses. Here we investigate how excessive innate immune responses to H5N1 impair subsequent adaptive T cell responses in the lungs. Using recombinant H1N1 and H5N1 strains sharing 6 internal genes, we demonstrate that H5N1 (2:6) infection in mice causes higher stimulation and increased migration of lung dendritic cells to the draining lymph nodes, resulting in higher numbers of virus specific T cells in the lungs. Despite robust T cell responses in the lungs, H5N1 (2:6) infected mice showed inefficient and delayed viral clearance as compared to H1N1 infected mice. In addition, we observed higher levels of inhibitory signals including increased PD1 and IL-10 expression by cytotoxic T cells in H5N1 (2:6) infected mice, suggesting that delayed viral clearance of H5N1 (2:6) was due to suppression of T cell functions in vivo. Importantly, H5N1 (2:6) infected mice displayed decreased numbers of tissue resident memory T cells as compared to H1N1 infected mice; however, despite decreased number of tissue resident memory T cells, H5N1 (2:6) were protected against a heterologous challenge from H3N2 virus (X31). Taken together, our study provides mechanistic insight for the prolonged viral replication and protracted illness observed in H5N1 infected patients. [ABSTRACT FROM AUTHOR]

Vaccination is the best way to prevent influenza virus infections, but the diversity of antigenically distinct isolates is a persistent challenge for vaccine development. In order to conquer the antigenic variability and improve influenza virus vaccine efficacy, our research group has developed computationally optimized broadly reactive antigens (COBRAs) in the form of recombinant hemagglutinins (rHAs) to elicit broader immune responses. However, previous COBRA H1N1 vaccines do not elicit immune responses that neutralize H1N1 virus strains in circulation during the recent years. In order to update our COBRA vaccine, two new candidate COBRA HA vaccines, Y2 and Y4, were generated using a new seasonal-based COBRA methodology derived from H1N1 isolates that circulated during 2013–2019. In this study, the effectiveness of COBRA Y2 and Y4 vaccines were evaluated in mice, and the elicited immune responses were compared to those generated by historical H1 COBRA HA and wild-type H1N1 HA vaccines. Mice vaccinated with the next generation COBRA HA vaccines effectively protected against morbidity and mortality after infection with H1N1 influenza viruses. The antibodies elicited by the COBRA HA vaccines were highly cross-reactive with influenza A (H1N1) pdm09-like viruses isolated from 2009 to 2021, especially with the most recent circulating viruses from 2019 to 2021. Furthermore, viral loads in lungs of mice vaccinated with Y2 and Y4 were dramatically reduced to low or undetectable levels, resulting in minimal lung injury compared to wild-type HA vaccines following H1N1 influenza virus infection.

Swine Flu or Influenza A (H1N1) is caused by one of several swine influenza A strains and its highly contagious. The transmission of the virus is from person-to-person and is similar to how seasonal influenza spreads. This report describes an Influenza A Virus (H1N1) outbreak in Asokore Mampong Sub-Municipal. Ninety-six (96) people were infected by the Influenza A (H1N1), and four (4) of them died. Those who died were lodging at the Sadler house; Jubilee House and Yaa Achiaa House. Three (3) health staff at KNUST hospital emergency unit were also infected, but they were treated and discharged. Three (3) of those who died as a result of the outbreak were males. An outbreak of H1N1 influenza type A caused by the H1N1 pdm09 virus on the campus of Kumasi Academy (KUMACA) led to Ninety-six (96) people becoming infected and four (4) dying. Several steps were taken by a national and regional multi-sectoral team from the World Health Organization, Ghana Health Service HQ as well as the Regional Health Directorate to manage the situation. Health education on H1NI must be intensified and sustained in the municipality as well as disease surveillance.

This work highlights the structure and dynamics of two trimeric HA proteins of the H1N1 virus from different origins, the pandemic Californian (HA Cal ) and its closest Indian neighbor (HA Ind ), reported in 2009 and 2018, respectively. Because of mutation, HA Ind acquires new N-glycosylation and epitope binding sites along with mutations at RBD, which might trigger an altered viral-host interaction mechanism. Molecular dynamics simulations performed on HA trimers for a period of 250 ns reveal the highly dynamic nature of HA Cal trimers inherited by the flexibility of HA monomers. In the trimer, the dynamics of one monomer are more pronounced compared to others, and the enhanced dynamics of RBD especially gain attention as they plays a key role during fusion. Conversely, the mutant HA Ind trimer effectively establishes more H-bond interactions, and accordingly, the trimer undergoes more stabilized dynamics with a relatively lower amplitude of RBD dynamics, as endorsed by the reduced RMSD, Rg, and SASA variations. The cooperative and anti-cooperative motions dissected for the subdomains of both strains also reveal a prominent anticorrelative motion of RBD against other subdomains. In agreement, the free energy landscape of stable HA Ind is also characterized by a single lowest wide energy basin instead of the two minimum energy basins of the HA Cal trimer. In essence, the mutant HA Ind acquires a highly stable conformation with novel functional features, which calls for (i) further investigation on the emerging mutation-mediated variation in viral-host binding mechanism and (ii) the need for further design of site-specific potential inhibitors to face future challenges.Communicated by Ramaswamy H. Sarma.

Mast cells can support the replication of influenza A virus, although how this occurs is poorly understood. In the present study, using quantitative MS, we analyzed the proteome of human mast cells infected with different influenza A virus strains at 12 h post‐infection. Forty‐one differentially expressed proteins were identified in human mast cells upon infection by the virulent H5N1 (A/Chicken/Henan/1/04) virus compared to the seasonal H1N1 (A/WSN/33) virus. Bioinformatic analyses confirmed that H1N1 significantly regulates the RNA degradation pathway via up‐regulation of CCR4‐NOT transcription complex subunit 4, whereas apoptosis could be suppressed by H5N1 via down‐regulation of the tumor protein p53 signaling pathway with P ≤ 0.05 at 12 h post‐infection. The hypoxia‐inducible factor‐1 signaling pathway of human mast cells is more susceptible to infection by H5N1 than by H1N1 virus. [ABSTRACT FROM AUTHOR]

Various serosurveys and studies were conducted globally on pandemic influenza. H1N1 virus reported so far provides ample evidence of differing perspectives, regarding its epidemiology especially with regard to prevalence, populations groups, and behaviour related to vaccine acceptance. A multigroup, cross-sectional survey among 658 healthy subjects was carried out, in Pune among students, health-care workers (HCWs), and soldiers to assess the seroprevalence of pandemic influenza H1N1 virus and its associated factors. The total sample size, based on forecasted prevalence of 33%, worked out to be 640. We studied 658 subjects including 103 students, 201 HCWs, and 354 serving soldiers. The sample for each group was selected from the respective study population by simple random sampling using a random number table. Haemagglutination inhibition test was carried out at the National Institute of Virology. The overall seroprevalence of pandemic influenza H1N1 (2009) virus was found to be 46.5% (95% confidence interval 42.6–50.4) which was adjusted to 39.4% after excluding those vaccinated. The availability of vaccine for high-risk group such as HCWs did not find much favour with the HCWs who did not accept vaccine for various reasons. Whereas only one student was vaccinated, 21.4% of HCWs and 32.5% of soldiers were vaccinated. Based on high seroprevalence of antibodies against H1N1 virus during pandemic, vaccination of general population is not recommended. However, high-risk groups and HCWs need to be protected with flu vaccine. There is a need to encourage HCWs for accepting vaccination. [ABSTRACT FROM AUTHOR]

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BACKGROUND: The 2009 H1N1 influenza epidemic saw a rise in the use of extracorporeal membrane oxygenation (ECMO) as a supportive therapy for refractory ARDS. We sought to determine whether ECMO utilization follows a seasonal pattern that matches the influenza season, and whether it can further be explained by the incidence of each influenza subtype. METHODS: We performed a longitudinal analysis of non-cardiac and cardiac-associated ECMO cases from the National In-patient Sample from 2005 to 2014, using overdispersed Poisson regression to evaluate associations with influenza incidence categorized by influenza-like illness and total positive influenza tests divided by subtype from the Centers for Disease Control and Prevention. RESULTS: Non-cardiac ECMO use was positively associated with influenza-like illness incidence in the current month (incidence risk ratio [IRR] 1.11, 95% confidence interval [CI] 1.07-1.15, P < .001) and with influenza-like illness in the previous month (IRR 1.09, 95% CI 1.05-1.14, P < .001). The 2009 H1N1 subtype had the strongest association with non-cardiac ECMO (IRR 1.19, 95% CI 1.09 - 1.31, P < .001). Cardiac ECMO was also positively associated with the incidence of influenza-like illness (IRR 1.05, 95% CI 1.01-1.09, P = .02). CONCLUSION: Non-cardiac and cardiac ECMO use in the United States were significantly associated with influenza incidence. The influenza A, H1N1 2009, subtype had the strongest association. [ABSTRACT FROM AUTHOR]

Swine Flu or Influenza A (H1N1) is caused by one of several swine influenza A strains and its highly contagious. The transmission of the virus is from person-to-person and is similar to how seasonal influenza spreads. This report describes an Influenza A Virus (H1N1) outbreak in Asokore Mampong Sub-Municipal. Ninety-six (96) people were infected by the Influenza A (H1N1), and four (4) of them died. Those who died were lodging at the Sadler house; Jubilee House and Yaa Achiaa House. Three (3) health staff at KNUST hospital emergency unit were also infected, but they were treated and discharged. Three (3) of those who died as a result of the outbreak were males. An outbreak of H1N1 influenza type A caused by the H1N1 pdm09 virus on the campus of Kumasi Academy (KUMACA) led to Ninety-six (96) people becoming infected and four (4) dying. Several steps were taken by a national and regional multi-sectoral team from the World Health Organization, Ghana Health Service HQ as well as the Regional Health Directorate to manage the situation. Health education on H1NI must be intensified and sustained in the municipality as well as disease surveillance. [ABSTRACT FROM AUTHOR]