After six months of exhaustive investigation, the global scientific community has been unable to identify the natural source of COVID-19, that is, the when, where and how it “jumped” from animals to humans.
Some now imply that we may never know the natural origin of COVID-19.
In a news article recently published by the international science journal Nature, the progress, or lack thereof, identifying the natural source of COVID-19 was reviewed.
According to the article, COVID-19 probably originated in bats, specifically horseshoe bats, which host two closely related coronaviruses, named RaTG13 and RmYN02, whose genomes are 96% and 93% identical to COVID-19, respectively.
Both coronavirus samples were isolated from bats in Yunnan Province, RaTG13 in 2013 and RmYN02 in 2019, and were studied in the Wuhan Institute of Virology.
Wuhan is where the outbreak of COVID-19 originated and about 1,000 miles from Yunnan.
The Nature article does not mention that RaTG13 is actually a duplicate of another bat coronavirus, BtCoV/4991, about which there is nearly no published experimental data since it was isolated in 2013, despite clearly being a Potential Pandemic Pathogen.
That is, except for the structure, analyzed only by Chinese scientists, practically nothing is known about RaTG13.
The Nature article also does not mention that the receptor-binding domain of RmYN02 showed only a 61.3% sequence identity with COVID-19, meaning it is highly unlikely that RmYN02 could even bind to human cells.
The Nature article suggests that pangolins (scaly anteaters), might be an intermediate host because some pangolin coronaviruses “share up to 92% of their genomes” with COVID-19, presumably bridging the gap between bats and humans.
When asked about that possibility, Dr Ralph Baric, a coronavirus expert from the University of North Carolina, in a March 15, 2020 interview, stated unequivocally that pangolins were not the source of COVID-19:
“Pangolins have over 3,000 nucleotide changes – no way they are the reservoir species [for COVID-19], absolutely no chance.”
Nevertheless, the receptor-binding domain of COVID-19 is structurally closer to pangolins than bats indicating a recombinant event,