MakeeLearn
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Joined: 9/11/2016 Status: offline
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The Bats Behind the Pandemic From Ebola to Covid-19, many of the deadliest viruses to emerge in recent years have the same animal source. April 9, 2020 https://www.wsj.com/articles/the-bats-behind-the-pandemic-11586440959 Behind a wall..... By Matt Ridley, Wall Street Journal, April 9, 2020: RaTG13 is the name, rank and serial number of an individual horseshoe bat of the species Rhinolophus affinis, or rather of a sample of its feces collected in 2013 in a cave in Yunnan, China. The sample was collected by hazmat-clad scientists from the Institute of Virology in Wuhan that year. Stored away and forgotten until January this year, the sample from the horseshoe bat contains the virus that causes Covid-19. The scientists were mostly sampling a very similar species with slightly shorter wings, called Rhinolophus sinicus, in a successful search for the origin of the virus responsible for the SARS epidemic of 2002-03. That search had alarming implications, which were largely ignored. In Shi tou Cave, south of Kunming, the capital of Yunnan, they found viruses in the bats droppings and anal swabs that were more similar to human SARS than anything found in palm civets, the small mammals that until then were presumed to be the source of human infection. Back in the laboratory, they found that one of the viruses from bat droppings, called WIV1, could thrive in monkey and human cells specially engineered to activate the gene for ACE2 receptors, the lock to which a coronavirusâs spike protein can fit as a key. This suggested that people could catch SARS directly from a bat dropping. Then in 2016, Ralph Baric and colleagues at the University of North Carolina at Chapel Hill showed that the same bat virus could infect live mice that had been engineered to express the human gene for the ACE2 receptor. The virus was poised for human emergence, as the title of Dr. Baricâ's paper put it. [….] Significantly, the same analysis shows that the most recent common ancestor of the human virus and the RaTG13 virus lived at least 40 years ago. So it is unlikely that the cave in Yunnan (a thousand miles from Wuhan) is where the first infection happened or that the culprit bat was taken from that cave to Wuhan to be eaten or experimented on. Rather, it is probable that somewhere much closer to Wuhan, there is another colony of bats carrying the same kind of virus. Unless other evidence emerges, it thus looks like a horrible coincidence that China's Institute of Virology, a high-security laboratory where human cells were being experimentally infected with bat viruses, happens to be in Wuhan, the origin of todays pandemic.
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