Up to now few members of the general public know about the research of Marc Eloit, a virology expert at the Pasteur Institute in Paris who led a study of Laotian bats in the summer of 2020. In the dead of night, Eloit's team used mist nets and canvas traps to snag hundreds of bats as they emerged from nearby caves. The team then gathered samples of saliva, urine and feces, then released the bats back into the darkness.
The fecal samples turned out to contain coronaviruses, which the scientists studied in high-security biosafety labs, known as BSL-3 (Bio-Safety Level 3), using specialized protective gear and air filters. Three of the Laotian coronaviruses were unusual: They carried a molecular hook on their surface very similar to the hook on the virus that causes COVID-19, called SARSCoV- 2. Like SARS-CoV-2, their hook allowed them to latch onto human respiratory cells.
According to virologist Eliot:
“It is even better than early strains of SARS-CoV-2,”
In other words, the similarity to the Covid -19 alpha variant was even more than what the team expected. Further, under the right circumstances the Laotian pathogens could also give rise to a pandemic such we are experiencing. Essentially, the case had been made that the origins of Covid -19 occurred in the wild, not a lab.
While a vociferous gaggle of conservative talking heads and right wing media (like the WSJ and FOX News) have conjectured that SARS-CoV-2’s impressive ability to infect human cells could not have evolved through a natural spillover from an animal, the new findings show otherwise.
In the words of University of Arizona virologist Michael Worley:
“That really puts to bed any notion that this virus had to have been concocted or somehow manipulated in a lab to be so good at infecting humans,”
Recall that when SARS-CoV-2 first emerged, its closest known relative was a bat coronavirus that Chinese researchers found in 2016 in a mine in southern China’s Yunnan province. RaTG13, as it is known, shares 96% of its genome with SARSCoV- 2. See e.g.
Based on the mutations carried by each virus, scientists have estimated that RaTG13 and SARSCoV- 2 share a common ancestor that infected bats about 40 years ago. In RaTG13, 11 of the 17 key building blocks of the domain are identical to those of SARS-CoV-2. (But in the three viruses from Laos, as many as 16 were identical — the closest match to date.)
Both viruses infect cells by using a molecular hook, called the “receptor-binding domain,” to latch onto their surface. RaTG13’s hook, adapted for attaching to bat cells, can cling only weakly to human cells. SARS-CoV-2’s hook, by contrast, can clasp cells in the human airway, the first step toward a potentially lethal case of COVID-19. See e.g. this image from a Physics Today study:
In concert all of this evidence shatters the myth that Covid -19 was laboratory- created or manipulated, as spouted yesterday on FOX ('The Story - Martha McCallum') by former CDC Director Robert Redfield - a long time Trump pet and medical puppet.
Medpage Today also skewered Redfield, citing "an apparent faulty understanding of basic virology". In other words, this character didn't get a proper virology education. It goes on to point out:
These bat viruses, along with more than a dozen others discovered in recent months in Laos, Cambodia, China and Thailand, also may help researchers better anticipate future pandemics. The viruses’ family trees offer hints about where potentially dangerous strains are lurking and which animals scientists should look at to find them.
Indeed, researcher Eloit predicted that there were many more relatives of SARS-CoV-2 left to find. To find other close relatives of SARS-CoV-2, wildlife virus experts checked their freezers full of old samples from across the world. They identified several similar coronaviruses from southern China, Cambodia and Thailand. Most came from bats, while a few came from scaly mammals known as pangolins. None was a closer relative than RaTG13.
To their credit, Eloit and his colleagues instead set out to find new coronaviruses. They traveled to northern Laos, about 150 miles from the mine where Chinese researchers had found RaTG13. Over six months they caught 645 bats belonging to 45 species. The bats harbored two dozen kinds of coronaviruses, three of which were strikingly similar to SARSCoV- 2 — especially in the receptor-binding domain.
Eloit speculated that one or more of these coronaviruses might be able to infect humans and cause mild disease. All of which confirms Laurie Garrett's sober take about how viruses emerge in the wild, from her book, The Coming Plague (p. 618):
"An individual microbe's world is limited only by the organism's mobility and its ability to tolerate various ranges of temperature, sunlight, oxygen, acidity or alkalinity. Wherever there may be an ideal soup for a microbe, it will eagerly take hold, immediately joining to the local microbial ecosystem of pushing and shoving struggle for survival.... In this fluid complexity human beings stomp about with swagger, elbowing their way without concern into one ecosphere after another. The human race seems equally complacent about blazing a path through a rainforest with bulldozers and arson - or using an antibiotic 'scorched earth' policy to chase unwanted microbes across the duodenum. "