Immunogenic and Protective Properties of Recombinant Hemagglutinin of Influenza A (H5N8) Virus.

In this study, we characterized recombinant hemagglutinin (HA) of influenza A (H5N8) virus produced in Chinese hamster ovary cells (CHO-K1s). Immunochemical analysis showed that the recombinant hemagglutinin was recognized by the serum of ferrets infected with influenza A (H5N8) virus, indicating that its antigenic properties were retained. Two groups of Balb/c mice were immunized with intramuscular injection of recombinant hemagglutinin or propiolactone inactivated A/Astrakhan/3212/2020 (H5N8) influenza virus.

An Investigation of Severe Influenza Cases in Russia during the 2022-2023 Epidemic Season and an Analysis of HA-D222G/N Polymorphism in Newly Emerged and Dominant Clade 6B.1A.5a.2a A(H1N1)pdm09 Viruses.

In Russia, during the COVID-19 pandemic, a decrease in influenza circulation was initially observed. Influenza circulation re-emerged with the dominance of new clades of A(H3N2) viruses in 2021-2022 and A(H1N1)pdm09 viruses in 2022-2023. In this study, we aimed to characterize influenza viruses during the 2022-2023 season in Russia, as well as investigate A(H1N1)pdm09 HA-D222G/N polymorphism associated with increased disease severity.

Pre-Pandemic Cross-Reactive Immunity against SARS-CoV-2 among Siberian Populations.

In December 2019, a new coronavirus, SARS-CoV-2, was found to in Wuhan, China. Cases of infection were subsequently detected in other countries in a short period of time, resulting in the declaration of the COVID-19 pandemic by the World Health Organization (WHO) on 11 March 2020. Questions about the impact of herd immunity of pre-existing immune reactivity to SARS-CoV-2 on COVID-19 severity, associated with the immunity to seasonal manifestation, are still to be resolved and may be useful for understanding some processes that precede the emergence of a pandemic virus.

COVID-19, Influenza, and Other Acute Respiratory Viral Infections: Etiology, Immunopathogenesis, Diagnosis, and Treatment. Part 2. Other Acute Respiratory Viral Infections.

The first part of this paper presented the current knowledge on two very significant respiratory diseases with high pandemic potential, COVID-19 and influenza. The second part reviews other pathogens that cause acute respiratory viral infections, ARVI, including parainfluenza viruses, adenoviruses, pneumoviruses and specifically respiratory syncytial virus, enteroviruses, rhinoviruses, bocaviruses, and seasonal coronaviruses. The review presents modern data on the structure and replication of viruses, epidemiology and immunopathogenesis of diseases, diagnostics, preventive vaccination, and antiviral drugs.

Re-Emergence of Circulation of Seasonal Influenza during COVID-19 Pandemic in Russia and Receptor Specificity of New and Dominant Clade 3C.2a1b.2a.2 A(H3N2) Viruses in 2021-2022.

The circulation of seasonal influenza in 2020-2021 around the world was drastically reduced after the start of the COVID-19 pandemic and the implementation of mitigation strategies. The influenza virus circulation reemerged in 2021-2022 with the global spread of the new genetic clade 3C.2a1b.

COVID-19, Influenza, and Other Acute Respiratory Viral Infections: Etiology, Immunopathogenesis, Diagnosis, and Treatment. Part I. COVID-19 and Influenza.

The paper briefly reviews pathogens causing acute respiratory viral infections (ARVIs), including influenza viruses; coronaviruses, including SARS-CoV-2; parainfluenza viruses, adenoviruses, pneumoviruses, and specifically respiratory syncytial virus and metapneumoviruses, enteroviruses, rhinoviruses, and bocaviruses. This review presents modern data on the structure and replication of viruses, epidemiology, and immunopathogenesis of diseases and on diagnostics, preventive vaccination, and antiviral drugs for the treatment of ARVIs. Special attention is paid to the SARS-CoV-2 virus caused COVID-19 pandemic with analyses of similarities and differences between COVID-19 and other ARVIs, first of all, influenza virus.

Genome Features of Probiotic Bifidobacteria Determining Their Strain-Specific Properties.

Unlabelled: was to analyze the genome features of the probiotic strains 379, 1, and 791 and study their antiviral activity.

Materials And Methods: Whole genome sequencing of three strains of bifidobacteria was performed on the MiSeq platform (Illumina Inc., USA).

Genome Features and Activity against Influenza A and SARS-CoV-2 Viruses of Six Probiotic Strains.

Purpose: The aim of this work was to analyze the complete genome of probiotic bacteria 8 RA 3, 90 TC-4, 39, 791, 1, and 379 and to test their activity against influenza A and SARS-CoV-2 viruses.

Methods: To confirm the taxonomic affiliation of the bacterial strains, MALDI TOF mass spectrometry and biochemical test systems were used. Whole genome sequencing was performed on the Illumina Inc.

An influenza A(H5N8) virus isolated during an outbreak at a poultry farm in Russia in 2017 has an N294S substitution in the neuraminidase and shows reduced susceptibility to oseltamivir.

This study aimed to assess the antiviral susceptibility of influenza A(H5N8) viruses isolated in Russia in 2014-2018. Genetic analysis of 57 Russian isolates with full genome sequences did not find any markers of reduced susceptibility to baloxavir. Only one strain bore an amino acid substitution associated with adamantane resistance (M2-S31N).

Evaluation of HA-D222G/N polymorphism using targeted NGS analysis in A(H1N1)pdm09 influenza virus in Russia in 2018-2019.

Outbreaks of influenza, which is a contagious respiratory disease, occur throughout the world annually, affecting millions of people with many fatal cases. The D222G/N mutations in the hemagglutinin (HA) gene of A(H1N1)pdm09 are associated with severe and fatal human influenza cases. These mutations lead to increased virus replication in the lower respiratory tract (LRT) and may result in life-threatening pneumonia.

Antibodies to Highly Pathogenic A/H5Nx (Clade 2.3.4.4) Influenza Viruses in the Sera of Vietnamese Residents.

To cause a pandemic, an influenza virus has to overcome two main barriers. First, the virus has to be antigenically new to humans. Second, the virus has to be directly transmitted from humans to humans.

Medicinal Mushrooms against Influenza Viruses.

This review provides results obtained by scientists from different countries on the antiviral activity of medicinal mushrooms against influenza viruses that can cause pandemics. Currently, the search for antiviral compounds is relevant in connection with the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Medicinal mushrooms contain biologically active compounds (polysaccharides, proteins, terpenes, melanins, etc.

First Data on Antiviral Activity of Aqueous Extracts from Medicinal Mushrooms from the Altai Mountains in Russia against Influenza Virus Type A.

Fungi are a promising source of biologically active compounds. Here we publish new data on the antiviral activity of some Agaricomycetes species. We studied the antiviral activity of the total polysaccharide fraction of aqueous extracts from fruiting bodies of eight Agaricomycetes (Hygrophorus agathosmus, H.

In silico design of influenza a virus artificial epitope-based T-cell antigens and the evaluation of their immunogenicity in mice.

The polyepitope strategy is promising approach for successfully creating a broadly protective flu vaccine, which targets T-lymphocytes (both CD4+ and CD8+) to recognise the most conserved epitopes of viral proteins. In this study, we employed a computer-aided approach to develop several artificial antigens potentially capable of evoking immune responses to different virus subtypes. These antigens included conservative T-cell epitopes of different influenza A virus proteins.

Immunogenicity and Protective Efficacy of Influenza A DNA Vaccines Encoding Artificial Antigens Based on Conservative Hemagglutinin Stem Region and M2 Protein in Mice.

Background: Development of a universal vaccine capable to induce antibody responses against a broad range of influenza virus strains attracts growing attention. Hemagglutinin stem and the exposed fragment of influenza virus M2 protein are promising targets for induction of cross-protective humoral and cell-mediated response, since they contain conservative epitopes capable to induce antibodies and cytotoxic T lymphocytes (CTLs) to a wide range of influenza virus subtypes.

Methods: In this study, we generated DNA vaccine constructs encoding artificial antigens AgH1, AgH3, and AgM2 designed on the basis of conservative hemagglutinin stem fragments of two influenza A virus subtypes, H1N1 and H3N2, and conservative M2 protein, and evaluate their immunogenicity and protective efficacy.

Severe cases of seasonal influenza and detection of seasonal A(H1N2) in Russia in 2018-2019.

Data obtained from monitoring cases of severe influenza, cases of vaccinated individuals, and unique cases were used to describe influenza viruses that circulated in Russia in the 2018-2019 epidemic season. A high proportion of the mutations D222G/N in A(H1N1)pdm09 HA was detected in fatal cases. Viruses of the B/Victoria lineage with deletions in HA were detected in Russia, and a reassortant seasonal influenza A(H1N2) virus was identified.

Correction: Severe cases of seasonal influenza in Russia in 2017-2018.

[This corrects the article DOI: 10.1371/journal.pone.

Severe cases of seasonal influenza in Russia in 2017-2018.

The 2017-2018 influenza epidemic season in Russia was characterized by a relatively low morbidity and mortality. We evaluated herd immunity prior to the 2017-2018 influenza season in hemagglutination inhibition assay, and performed characterization of influenza viruses isolated from severe or fatal influenza cases and from influenza cases in people vaccinated in the fall of 2017. During the 2017-2018 epidemic season, 87 influenza A and B viruses were isolated and viruses of the 75 influenza cases, including selected viral isolates and viruses analyzed directly from the original clinical material, were genetically characterized.

Humoral immunity to influenza in an at-risk population and severe influenza cases in Russia in 2016-2017.

This work aimed to analyze the herd immunity to influenza among a Russian population living in regions with an increased risk of emergence of viruses with pandemic potential, and to isolate and investigate virus strains from severe influenza cases, including fatal cases, during the 2016-2017 epidemic season. In November 2016 - March 2017 highly pathogenic influenza outbreaks were registered in Russia among wild birds and poultry. No cases of human infection were registered.

Reintroduction of highly pathogenic avian influenza A/H5N8 virus of clade 2.3.4.4. in Russia.

In the spring of 2016, a loss of wild birds was observed during the monitoring of avian influenza virus activity in the Republic of Tyva. That outbreak was caused by influenza H5N8 virus of clade 2.3.

Fatal Cases of Seasonal Influenza in Russia in 2015-2016.

The influenza epidemic in 2015-2016 in Russia is characterized by a sharp increase of influenza cases (beginning from the second week of 2016) with increased fatalities. Influenza was confirmed in 20 fatal cases registered among children (0-10 years), in 5 cases among pregnant women, and in 173 cases among elderly people (60 years and older). Two hundred and ninety nine people died from influenza were patients with some chronic problems.

Highly pathogenic influenza H5N1 virus of clade 2.3.2.1c in Western Siberia.

In the spring of 2015, avian influenza virus surveillance in Western Siberia resulted in isolation of several influenza H5N1 virus strains. The strains were isolated from several wild bird species. Investigation of biological features of those strains demonstrated their high pathogenicity for mammals.

Influenza A(H5N8) virus isolation in Russia, 2014.

In this study, we report the isolation of influenza A(H5N8) virus from a Eurasian wigeon (Anas penelope) in Sakha Republic of the Russian Far East. The strain A/wigeon/Sakha/1/2014 (H5N8) has been shown to be pathogenic for mammals. It is similar to the strains that caused outbreaks in wild birds and poultry in Southeast Asia and Europe in 2014.