Publications by authors named "Kawaoka Y"

The continuing emergence of immune evasive SARS-CoV-2 variants and the previous SARS-CoV-1 outbreak collectively underscore the need for broadly protective sarbecovirus vaccines. Targeting the conserved S2 subunit of SARS-CoV-2 is a particularly promising approach to elicit broad protection. Here, we describe a nanoparticle vaccine displaying multiple copies of the SARS-CoV-1 S2 subunit.

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Influenza B viruses pose a significant threat to global public health, leading to severe respiratory infections in humans and, in some cases, death. During the last 50 years, influenza B viruses of two antigenically distinct lineages (termed 'Victoria' and 'Yamagata') have circulated in humans, necessitating two different influenza B vaccine strains. In this study, we devised a novel vaccine strategy involving reciprocal amino acid substitutions at sites where Victoria- and Yamagata-lineage viruses differ, leading to the generation of 'hybrid' vaccine viruses with the potential to protect against both lineages.

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This study compared intestinal DNA phage dynamics and gut microbiota changes observed at the onset of coronavirus disease 2019 (COVID-19). The study participants included 19 healthy individuals and 19 patients with severe acute respiratory syndrome coronavirus 2 infection. Significant differences were observed in the diversity of the intestinal DNA virome after the onset of COVID-19 compared with that in healthy individuals.

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Vaccination is the most effective strategy to combat influenza. Ideally, potent and persistent vaccine effects would be induced with a single vaccine dose. Here, we designed a virus-like particle (VLP)-based vaccine presenting multiple copies of the influenza hemagglutinin (HA) from A/Puerto Rico/8/1934 (PR8HA-VLP) and examined its immunogenicity and protective efficacy in ferrets.

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The reverse genetics system, which allows the generation of influenza viruses from plasmids encoding viral genome, is a powerful tool for basic research on viral infection mechanisms and application research such as vaccine development. However, conventional plasmid construction using Escherichia coli (E.coli) cloning is time-consuming and has difficulties handling DNA encoding genes toxic for E.

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Safe, effective, and low-cost oral antiviral therapies are needed to treat those at high risk for developing severe COVID-19. To that end, we performed a high-throughput screen to identify non-peptidic, non-covalent inhibitors of the SARS-CoV-2 main protease (Mpro), an essential enzyme in viral replication. NZ-804 was developed from a screening hit through iterative rounds of structure-guided medicinal chemistry.

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Background: Emergence of SARS-CoV-2 variants that escape neutralising antibodies hampers the development of vaccines and therapeutic antibodies against SARS-CoV-2. IGHV3-53/3-66-derived public antibodies, which are generally specific to the prototype virus and are frequently induced in infected or vaccinated individuals, show minimal affinity maturation and high potency against prototype SARS-CoV-2.

Methods: Monoclonal antibodies isolated from a Delta breakthrough infection case were analysed for cross-neutralising activities against SARS-CoV-2 variants.

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Highly pathogenic avian influenza (HPAI) H5 viruses from different clades have been circulating globally, threatening wild/domestic birds and mammals. Given frequent spillovers and high mortality among mammals, coupled with our inability to predict which clade of H5 virus has pandemic potential, cross-clade protective HPAI H5 vaccines are urgently needed. Here, we demonstrate the applicability of a lipid nanoparticle-based mRNA vaccine modality to induce cross-protective immunity against lethal HPAI virus infection.

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The reduced susceptibility of mRNA vaccines and diminished neutralizing activity of therapeutic monoclonal antibodies against Omicron variants, including BQ.1.1, XBB, and their descendants, highlight the importance of antiviral therapies.

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Recombinant influenza virus neuraminidase (NA) is a promising broadly protective influenza vaccine candidate. However, the recombinant protein alone is not sufficient to induce durable and protective immune responses and requires the coadministration of immunostimulatory molecules. Here, we evaluated the immunogenicity and cross-protective potential of a recombinant influenza virus N2 neuraminidase vaccine construct, adjuvanted with a toll-like receptor 9 (TLR9) agonist (CpG 1018® adjuvant), and alum.

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We generated SARS-CoV-2 variants resistant to three SARS-CoV-2 main protease (M) inhibitors (nirmatrelvir, TKB245, and 5h), by propagating the ancestral SARS-CoV-2 in VeroE6 cells with increasing concentrations of each inhibitor and examined their structural and virologic profiles. A predominant E166V-carrying variant (SARS-CoV-2), which emerged when passaged with nirmatrelvir and TKB245, proved to be resistant to the two inhibitors. A recombinant SARS-CoV-2 was resistant to nirmatrelvir and TKB245, but sensitive to 5h.

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Background: Older adults (aged ≥65 years) show increased susceptibility to severe disease with influenza virus infection, accounting for 70-85% of annual influenza-related fatalities in the USA. Stimulating mucosal antibodies and T cells might enhance the low vaccine effectiveness seen in older adults for currently licensed inactivated influenza vaccines, which induce mainly serum antibodies. We aimed to evaluate the safety and immunogenicity of the intranasal H3N2 M2-deficient single-replication (M2SR) vaccine, alone or coadministered with a licensed inactivated influenza vaccine (Fluzone High-Dose Quadrivalent; hereafter referred to as Fluzone HD), in older adults.

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Article Synopsis
  • An unprecedented outbreak of highly pathogenic H5N1 avian influenza (HPAI H5N1) affected bovine herds in the USA in spring 2024, leading to infections in other animals and potential spillover to humans.
  • Researchers isolated HPAI H5N1 virus from infected cow milk and studied its impact on mice and ferrets, finding that it spread throughout these animals, including to mammary glands, similar to previous strains.
  • Although the bovine H5N1 virus showed some ability to bind to human respiratory tissues and transmit minimally among ferrets, it exhibited features that raise concerns about potential infection and spread in mammals.
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Article Synopsis
  • * Research on the viruses showed that they were susceptible to various antiviral medications, including remdesivir and oseltamivir, without mutations that could lead to reduced effectiveness of these treatments.
  • * Despite the co-infections, the treated patients did not experience severe symptoms, highlighting the importance of ongoing monitoring of these viruses as they evolve to inform public health strategies.
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Background: Influenza viruses can cause zoonotic infections that pose public health risks. Surveillance of influenza A and B viruses is conducted globally; however, information on influenza C and D viruses is limited. Longitudinal monitoring of influenza C virus in humans has been conducted in several countries, but there has been no long-term monitoring of influenza D virus in humans.

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Studies of SARS-CoV-2 incidence are important for response to continued transmission and future pandemics. We followed a rural community cohort with broad age representation with active surveillance for SARS-CoV-2 identification from November 2020 through July 2022. Participants provided serum specimens at regular intervals and following SARS-CoV-2 infection or vaccination.

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Article Synopsis
  • - The study focuses on monitoring the evolution of SARS-CoV-2 variants to assess their ability to evade immune responses, emphasizing the importance of different neutralization assays and various serum samples.
  • - Comparisons were made among datasets using human, hamster, and mouse serum, revealing that animal models, especially hamsters, generally yielded higher neutralization titers than human samples, while showing consistent patterns across assays.
  • - The findings suggest a shift in SARS-CoV-2 surveillance strategies from relying solely on human serum from first infections to incorporating serum from animal models, particularly hamsters, for more reliable results.
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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) often causes severe viral pneumonia. Although many studies using mouse models have examined the pathogenicity of SARS-CoV-2, COVID-19 pathogenesis remains poorly understood. In vivo imaging analysis using two-photon excitation microscopy (TPEM) is useful for elucidating the pathology of COVID-19, providing pathological insights that are not available from conventional histological analysis.

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Background: World Health Organisation (WHO) and USA Centers for Disease Control and Prevention (U.S. CDC) recommendations now allow simultaneous administration of COVID-19 and other vaccines.

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Human infections caused by viral pathogens trigger a complex gamut of host responses that limit disease, resolve infection, generate immunity, and contribute to severe disease or death. Here, we present experimental methods and multi-omics data capture approaches representing the global host response to infection generated from 45 individual experiments involving human viruses from the Orthomyxoviridae, Filoviridae, Flaviviridae, and Coronaviridae families. Analogous experimental designs were implemented across human or mouse host model systems, longitudinal samples were collected over defined time courses, and global multi-omics data (transcriptomics, proteomics, metabolomics, and lipidomics) were acquired by microarray, RNA sequencing, or mass spectrometry analyses.

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