Study Confirms COVID-19 Has Natural Origins, Could Still Be Circulating in Animals and Might Jump into Humans Once Again
8The first most likely scenario says the virus developed pathogenic ability before entering humans
Till date scientists have not found any direct bat to human transmission which also now goes to suggest that a third intermediate party was involved between humans and bats. This scenario then also suggests that both spike proteins of the virus were already evolved before entering humans. This means that in such a scenario, its pre-developed pathogenic features would have made an epidemic emerge rapidly simply because it would have already possessed the pathogenic ability to spread between humans.
9The second less likely scenario
In the second suggested scenario, the virus is not assumed to have any pathogenic abilities before jumping on to humans. It evolved after leaving an animal host to a human host and then evolved to its current pathogenic state the way it exists now in the human population. Scientists say that there are pangolins (armadillo looking animals) living in Asia and Africa who possess the coronavirus that have similar RBD structure to that of SARS-CoV2. Thus, it also means that the coronavirus could have come directly from pangolins or been transmitted from the intermediary host like a civet or ferret.
10SARS-CoV-2 shares similarities to bird flu
The other spike protein, the cleavage site, scientists say could have evolved within the human host and could have remain undetected in the initial stages of the epidemic. In fact, research has found the cleavage site of SARS-CoV-2 similar to the cleavage sites of bird flu. This is what could have started the epidemic because the highly evolved virulent cleavage site would have now become more capable of spreading among humans.
11The dire warning, coronavirus could strike again
Regardless of either scenarios, they both have animal host involved. This is what made Study Co-author Andrew Rambault warn that it is difficult to figure out at this juncture which scenario could SARS-CoV2 could be attributed today. He says if SARS-CoV2 entered a human host in its present pathogenic form from animals, then this could mean future outbreaks. This is because the illness-causing strain of the virus could still be circulating in the animal population and might once again jump into humans. He says there are low chances of the second scenario of a non-pathogenic coronavirus entering humans and then evolving properties of SARS-CoV2.
This study was published in the Journal Nature Medicine and reported in scripps research