NATURE : Menachery & Baric "We generated (created) and characterized a chimeric virus expressing spike of bat coronavirus SHC014 in a mouse-adapted SARS-CoV backbone; stitching together virus & furin (FCS).
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This is the key paper and IMO, is strong evidence that this coronavirus was around from 2015 and after, based on this work and maybe even before.
In this one paper, they told us what they did, how they did it, they stitched together viruses, pieces of virus, creating chimeric deadly viruses, lethal, inserting furin cleavage sites (FCS) to assess the spillover and infectiousness and lethality, with no vaccine or drug possible to tame it. They said so, read the abstract below.
Key statement and the term ‘generated’ means they CREATED:
“Here we examine the disease potential of a SARS-like virus, SHC014-CoV, which is currently circulating in Chinese horseshoe bat populations1. Using the SARS-CoV reverse genetics system2, we generated and characterized a chimeric virus expressing the spike of bat coronavirus SHC014 in a mouse-adapted SARS-CoV backbone.”
…"can efficiently use multiple orthologs of the SARS receptor human angiotensin converting enzyme II (ACE2), replicate efficiently in primary human airway cells and achieve in vitro titers equivalent to epidemic strains of SARS-CoV.”
“in vivo experiments demonstrate replication of the chimeric virus in mouse lung with notable pathogenesis.”
“Evaluation of available SARS-based immune-therapeutic and prophylactic modalities revealed poor efficacy; both monoclonal antibody and vaccine approaches failed to neutralize and protect from infection with CoVs using the novel spike protein.”
“On the basis of these findings, we synthetically re-derived an infectious full-length SHC014 recombinant virus and demonstrate robust viral replication both in vitro and in vivo. Our work suggests a potential risk of SARS-CoV re-emergence from viruses currently circulating in bat populations.”