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US: WSU researchers show that simply replacing sars-cov-2 RBD with Russian bat RBD region can escape immunity of current spike vaccines

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  • US: WSU researchers show that simply replacing sars-cov-2 RBD with Russian bat RBD region can escape immunity of current spike vaccines

    https://journals.plos.org/plospathog...l.ppat.1010828
    Seifert SN, Bai S, Fawcett S, Norton EB, Zwezdaryk KJ, Robinson J, et al. (2022) An ACE2-dependent Sarbecovirus in Russian bats is resistant to SARS-CoV-2 vaccines. PLoS Pathog 18(9): e1010828. https://doi.org/10.1371/journal.ppat.1010828
    Abstract

    Spillover of sarbecoviruses from animals to humans has resulted in outbreaks of severe acute respiratory syndrome SARS-CoVs and the ongoing COVID-19 pandemic. Efforts to identify the origins of SARS-CoV-1 and -2 has resulted in the discovery of numerous animal sarbecoviruses–the majority of which are only distantly related to known human pathogens and do not infect human cells. The receptor binding domain (RBD) on sarbecoviruses engages receptor molecules on the host cell and mediates cell invasion. Here, we tested the receptor tropism and serological cross reactivity for RBDs from two sarbecoviruses found in Russian horseshoe bats. While these two viruses are in a viral lineage distinct from SARS-CoV-1 and -2, the RBD from one virus, Khosta 2, was capable of using human ACE2 to facilitate cell entry. Viral pseudotypes with a recombinant, SARS-CoV-2 spike encoding for the Khosta 2 RBD were resistant to both SARS-CoV-2 monoclonal antibodies and serum from individuals vaccinated for SARS-CoV-2. Our findings further demonstrate that sarbecoviruses circulating in wildlife outside of Asia also pose a threat to global health and ongoing vaccine campaigns against SARS-CoV-2
    ...

    Khosta virus receptor binding domains are distinct from human viruses


    Khosta-1 and -2 were identified by Alkhovsky and colleagues in bat samples collected between March-October 2020 near Sochi National Park [12]. Phylogenetic analysis of the conserved viral gene, Orf1ab, revealed these viruses were most closely related to another sarbecovirus found in Bulgaria in 2008 (known as BM48-31 or Bg08), and form a lineage sarbecoviruses distinct from human pathogens, SARS-CoV-1 and -2 [12]. A list of viruses and accession numbers used in this study can be found in Table 1. Phylogenetic analysis of the spike RBD further reflected the close relatedness between Khosta -1 and -2 with BM48-31 and other clade 3 RBD viruses we have previously tested from Uganda and Rwanda [1,13] (Fig 1A). Clade 3 RBDs, including the Khosta viruses, contain a truncated surface-exposed loop, as compared to the ACE2-dependent, clade 1 viruses such as SARS-CoV, and additionally vary in many of the residues known for clade 1 viruses to interact with human ACE2 [1,2,13,14].
    ...

    Our findings with chimeric, SARS-CoV-2 spike show that just replacing the RBD is sufficient to reduce efficacy of SARS-CoV-2 spike-directed vaccines (Fig 4). However, sarbecovirus recombination in nature typically occurs via template switching resulting in acquisition of regions larger than the NTD [42]. Thus, a naturally recombinant virus with Khosta 2 may actually acquire more Khosta 2 spike, which as we show here with full protein, is also infectious against human cells and ACE2 (Fig 3). Taken together, our findings with the Khosta viruses underscore the urgent need to develop broader-protecting universal Sarbecovirus vaccines.

    _____________________________________________

    Ask Congress to Investigate COVID Origins and Government Response to Pandemic.

    i love myself. the quietest. simplest. most powerful. revolution ever. ---- nayyirah waheed

    "...there’s an obvious contest that’s happening between different sectors of the colonial ruling class in this country. And they would, if they could, lump us into their beef, their struggle." ---- Omali Yeshitela, African People’s Socialist Party

    (My posts are not intended as advice or professional assessments of any kind.)
    Never forget Excalibur.

  • #2
    Scientists have discovered a bat in Russia carrying a virus that is similar COVID-19. Washington State University researchers have been studying it.

    Bat-borne virus, similar to COVID-19, piques interest of WSU researchers

    Scientists have discovered a bat in Russia carrying a virus that is similar COVID-19. Washington State University researchers have been studying it.

    Author: Tim Gordon
    Published: 5:13 PM PDT September 25, 2022

    Updated: 5:33 PM PDT September 25, 2022

    PULLMAN, Wash. — Researchers at Washington State University are raising concerns over the discovery of a virus with some of the same characteristics as COVID-19. At the same time, they hope that the discovery will lead to more progress in vaccine prevention...
    _____________________________________________

    Ask Congress to Investigate COVID Origins and Government Response to Pandemic.

    i love myself. the quietest. simplest. most powerful. revolution ever. ---- nayyirah waheed

    "...there’s an obvious contest that’s happening between different sectors of the colonial ruling class in this country. And they would, if they could, lump us into their beef, their struggle." ---- Omali Yeshitela, African People’s Socialist Party

    (My posts are not intended as advice or professional assessments of any kind.)
    Never forget Excalibur.

    Comment


    • #3
      An ACE2-dependent Sarbecovirus in Russian bats is resistant to SARS-CoV-2 vaccines - PLOS

      September 22, 2022, 02:18 PM
      Published: September 22, 2022

      Author summary SARS-CoV-2, the sarbecovirus behind COVID-19, emerged in the human population after cross-species transmission from an animal source. While hundreds of sarbecoviruses have been discovered, predominantly in bats in Asia, the majority are not capable of infecting human cells. Khosta-2, a sarbecovirus discovered in Russia, has been shown to interact with the same entry receptor as SARS-CoV-2. In this study, we tested how well the spike proteins from these bat viruses infect human cells under different conditions. We found that the spike from virus, Khosta-2, could infect cells similar to human pathogens using the same entry mechanisms, but was resistant to neutralization by serum from individuals who had been vaccinated for SARS-CoV-2.


      Stephanie N. Seifert, Shuangyi Bai, Stephen Fawcett, Elizabeth B. Norton, Kevin J. Zwezdaryk, James Robinson, Bronwyn Gunn, Michael Letko

      Abstract

      Spillover of sarbecoviruses from animals to humans has resulted in outbreaks of severe acute respiratory syndrome SARS-CoVs and the ongoing COVID-19 pandemic. Efforts to identify the origins of SARS-CoV-1 and -2 has resulted in the discovery of numerous animal sarbecoviruses–the majority of which are only distantly related to known human pathogens and do not infect human cells. The receptor binding domain (RBD) on sarbecoviruses engages receptor molecules on the host cell and mediates cell invasion. Here, we tested the receptor tropism and serological cross reactivity for RBDs from two sarbecoviruses found in Russian horseshoe bats. While these two viruses are in a viral lineage distinct from SARS-CoV-1 and -2, the RBD from one virus, Khosta 2, was capable of using human ACE2 to facilitate cell entry. Viral pseudotypes with a recombinant, SARS-CoV-2 spike encoding for the Khosta 2 RBD were resistant to both SARS-CoV-2 monoclonal antibodies and serum from individuals vaccinated for SARS-CoV-2. Our findings further demonstrate that sarbecoviruses circulating in wildlife outside of Asia also pose a threat to global health and ongoing vaccine campaigns against SARS-CoV-2

      Published: September 22, 2022 https://doi.org/10.1371/journal.ppat.1010828 Stephanie N. Seifert, Shuangyi Bai, Stephen Fawcett, Elizabeth B. Norton, Kevin J. Zwezdaryk, James Robinson, Bronwyn Gunn, Michael Letko Abstract Spillover of sarbecoviruses from animals to humans has resulted in outbreaks of severe acute

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