Originally Posted by
Sherkeu
I've read conflicting things on this. Some assert that the pangolin is just a victim rather than a vector...but I am not knowledgeable enough to compare theories. They have a 2013 bat virus in Yunnan, and an early 2019 pangolin virus from a confiscation in Guangdong that are most similar to the human virus. What happened in late 2019 though remains unknown. That bat virus doesnt infect that pangolin and infected pangolins did not transmit to their human carers over months of close proximity (or so they said).
The lab in Wuhan created chimeras to replicate how it could jump to humans (paper was in 2015). They had animals there with in vivo experiments. Not much is said about that since the pandemic began. I take their word when virologists say they can tell when things are spliced into a genome, and that Covid has no evidence of it.
There are a lot of pieces missing. Might be too late to find them now.
Just to be clear neither Pangolin-CoV-2019 nor the bat virus RaTG13 is a direct ancestor to Covid-19. RaTG13 is the closest relative but not an ancestor. Pangolin-CoV-2019 is even more distantly related but it or a closely related Pangolin virus supplied important genes that give Covid-19 specific features to it’s spike that make if very efficient in infecting humans.
This exchange of genetic material from Pangolin-CoV-2019 to the real Covid-19 direct ancestor is very unlikely to have been deliberate manipulation for 2 reasons:
First, we can’t even find the direct ancestor after a year of intense search, so how would a lab have had it 18 months ago?
Second, while the spike protein in the Pangolin virus is very efficient for infecting humans this wasn’t know prior to seeing Covid itself. Similarly, the bat virus couldn’t infect humans. So essentially the researcher would have to have been splicing together random chunks of random viruses to see if they could make something that infects humans. This isn’t how a research would proceed with something like this they would take parts of viruses already know to infect humans.
Nature, on the other hand does this kind of thing all the time RNA viruses undergo recombination all the time. Most, like Covid, show signs of numerous recombination events. For this to happen either the bat virus would have needed to infect a Pangolin or the Pangolin virus would have needed to infect a bat. Even if the two viruses are not very infectious across species this can still occur on occasion. In this case it looks like the bat virus infected the Pangolin. The resultant virus isn’t very infectious to bats so it would have been facing a dead end if it was stuck inside a bat. Since it was infectious to both Pangolins and humans it could spread within Pangolins until one of them was take to the Wuhan market where it jumped to humans.
It’s possible that both jumped to a third species but this is completely unnecessary and would require 2 unlikely infections simultaneous rather than just one. Also, we now know that Covid-19 neutralizing antibodies can be found in wild bats and Pangolins in SE Asia indicating closely related viruses or Corvid itself was already circulating there.