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The article covered this. When collecting samples from the wild they aren't collecting viable virus, they're collecting samples which have mRNA in them. Those
by lamontcg 5y ago
The article covered this.
When collecting samples from the wild they aren't collecting viable virus, they're collecting samples which have mRNA in them. Those samples just won't infect anyone at all.
While collecting the samples they're of course exposed to the environment and could have gotten sick, but they have dramatically less exposure to the environment that the workers who collect bat guano for fertilizer in China, or the people who clean the cages in the wet markets. It would be highly unlikely that one of them was naturally patient zero when there's a million times more human exposure going on in China. And hopefully they were wearing respirators in the caves and mines since they know the risks.
When it comes to the live virus the problem is that SARS-CoV-2 doesn't look like any other known virus. The difference between it and RaTG13 is still 4% which is like the difference between us and gorillas. It is a few decades of viral evolution and serial passage through many millions of hosts away. So for a lab that was all about finding new sequences and publishing them they would have had to keep this new viral backbone perfectly secret, they would have had to keep this new ACE2-infecting spike protein perfectly secret. Then there would have had to be some novel lab accident since SARS-CoV-2 requires aerosolized particles to be breathed in, you don't get it off surface transmission so the petri dish binding studies don't produce an environment where a lab accident is very possible.
- native_samples 5y ago"When collecting samples from the wild they aren't collecting viable virus, they're collecting samples which have mRNA in them. Those samples just won't infect anyone at all." None of this is right. RNA (of which mRNA is just a subtype) is extremely unstable and degrades almost immediately unless carefully protected, which is why viruses need a capsid and why mRNA vaccines need cold chains. You can't just touch some animal and collect raw RNA. Also the only type of thing a virologist could recover from a bat of any interest to them is viable virus because their whole goal is to study actual viruses. "Then there would have had to be some novel lab accident since SARS-CoV-2 requires aerosolized particles to be breathed in" There's nothing unexpected about that. These supposedly novel lab accidents happen all the time. Viruses constantly escape from labs. SARS1 has escaped in China many times, and the last foot-and-mouth outbreak in the UK came from a lab that had captured samples from the previous outbreak and kept them replicating. "petri dish binding studies don't produce an environment where a lab accident is very possible" Virologists don't only try to grow viruses in petri dishes. Look up serial passage. Animals are frequently used for that purpose. The WIV has been found to have been developing and buying bat cages. It's not really disputed that they were infecting live animals with viruses.
- lamontcg 5y agoYeah I meant RNA but it was early in the morning and my fingers autocorrected to mRNA. And many samples ARE degraded and only partial reads can be recovered. > “These samples are not like huge vials of blood,” Rasmussen said. “It’s not like a big Erlenmeyer flask of green liquid.” Researchers would have to grow the virus in cells in order to stand a real chance of infecting people, she added, and it’s difficult to grow viruses from these swabbed samples even if you try to. There’s not much virus in them, and what you get tends to be contaminated with virus-killing detritus. “Technically it’s very challenging to directly isolate virus from field samples from wild animals. So that makes it unlikely that just handling those samples would result in some kind of infection.” Finally, Rasmussen added, the chemical solution that’s used to stabilize the viral RNA for sequencing is a very potent disinfectant its own right. (from the title article) PCR amplification means that you can find the needle in the haystack and find enough RNA to construct aa genome out of it. A lot of the time you only get partial reads or don't get the whole genome. There isn't enough viable virus there in order to infect anyone.
- native_samples 5y agoYou skipped over the second part of my response. I'll point it out again: "Researchers would have to grow the virus in cells in order to stand a real chance of infecting people" They were filing patents on designs for bat cages. Videos from inside the WIV before COVID showed live bats. They were doing far more than growing virus in cells, they were growing them in live animals, as virologists typically do. "PCR amplification means that you can find the needle in the haystack and find enough RNA to construct aa genome out of it" This would be relevant if virologists were mere lab technicians running PCR tests, but they aren't.
- spfzero 5y agoThe difference between us and gorillas is best understood as the number of genes, not the % of nucleotides. Virus genomes are much, much smaller. Since viruses can multiply so quickly, when grown in large numbers of lab mice they can mutate relatively quickly into something with a "desirable" trait. In fact if as you say the virus has passed through millions of wild hosts on its way to being perfectly adapted to infecting human lungs, why has no one found even one of those millions of hosts?
- lamontcg 5y agoThey're still several decades of evolution away, given how fast viruses mutate in the wild. > We confirm that a direct proximal ancestor to SARS-CoV-2 is yet to be sampled, since the closest relative shared a common ancestor with SARS-CoV-2 approximately 40 years ago https://www.biorxiv.org/content/10.1101/2021.01.22.427830v3 https://www.biorxiv.org/content/10.1101/2021.01.22.427830v3 And do you have any idea how many animals there are in China? There's 1.4 billion people to start with. There's 100 to 100,000 more vertebrates than people in the world. Take even 50,000 samples and you're still barely scraping the surface.