New research findings published in the reputed journal Nature Medicine says that SARS-CoV-2, the new coronavirus that causes COVID-19, is the result of the natural process of evolution rather than a manipulated genetic engineering.
Since the start of the COVID-19 outbreak, researchers have been trying to grapple with the origins of the virus. Initially, experts linked the virus to the seafood market in Wuhan, China, while later study suggested that the virus may have spread to humans from illegally trafficked mammals called pangolins. New research deduces the origin of the new coronavirus from analyzing the genomic data available.
Andersen and his team also looked at spike proteins — features that coronaviruses use to bind to the membrane of the human or animal cells that they infect. The new research looked at two components of spike proteins: the receptor-binding domain (RBD), which latches onto healthy host cells, and the cleavage site, which opens up the virus and allows it to penetrate the host cell. “These two features of the virus rule out laboratory manipulation as a potential origin for SARS-CoV-2,” explains Andersen.
Two possible origin scenarios
One scenario, researchers say, is that the virus evolved to become pathogenic in an animal and then jumped to humans. This would be in line with how other coronaviruses, such as SARS and MERS, originated.
In this scenario, the probability of future outbreaks is higher, as the pathogenic strain of the virus would still be circulating in animals and could jump back into humans at any point.
In the second scenario, the virus is nonpathogenic in animals but jumped into humans and evolved into a disease. This scenario supports the theory that places pangolins at the start of the outbreak.
Even though the authors caution that it is impossible to tell which scenario is more likely to be true at this point, Josie Golding, the epidemics lead at the Wellcome Trust, a research charity based in London says: the findings are “crucially important to bring an evidence-based view to the rumors that have been circulating about the origins of the virus (SARS-CoV-2) causing COVID-19.”
Since the start of the COVID-19 outbreak, researchers have been trying to grapple with the origins of the virus. Initially, experts linked the virus to the seafood market in Wuhan, China, while later study suggested that the virus may have spread to humans from illegally trafficked mammals called pangolins. New research deduces the origin of the new coronavirus from analyzing the genomic data available.
Andersen and his team also looked at spike proteins — features that coronaviruses use to bind to the membrane of the human or animal cells that they infect. The new research looked at two components of spike proteins: the receptor-binding domain (RBD), which latches onto healthy host cells, and the cleavage site, which opens up the virus and allows it to penetrate the host cell. “These two features of the virus rule out laboratory manipulation as a potential origin for SARS-CoV-2,” explains Andersen.
Two possible origin scenarios
One scenario, researchers say, is that the virus evolved to become pathogenic in an animal and then jumped to humans. This would be in line with how other coronaviruses, such as SARS and MERS, originated.
For the new coronavirus, the authors suggest that bats are the most likely carrier, as SARS-CoV-2 is very similar to a bat coronavirus. Other experts have supported this theory, too. Andersen and colleagues also suggest that it is likely that another intermediate animal host transmitted the virus from bats to humans.
In this scenario, the probability of future outbreaks is higher, as the pathogenic strain of the virus would still be circulating in animals and could jump back into humans at any point.
In the second scenario, the virus is nonpathogenic in animals but jumped into humans and evolved into a disease. This scenario supports the theory that places pangolins at the start of the outbreak.
Even though the authors caution that it is impossible to tell which scenario is more likely to be true at this point, Josie Golding, the epidemics lead at the Wellcome Trust, a research charity based in London says: the findings are “crucially important to bring an evidence-based view to the rumors that have been circulating about the origins of the virus (SARS-CoV-2) causing COVID-19.”