Avian (bird) influenza virus and avian infectious bronchitis virus are coronaviruses, which elicit similar symptoms, are major pathogens long-circulating in Chinese poultry populations and have resulted in great economic losses for China due to respiratory disease and reduced egg production.
Avian influenza viruses are capable of infecting humans and multiple outbreaks have occurred in China, H5N1 since 2003 and H7N9 in 2013.
It is no wonder, therefore, that China has devoted an enormous amount of scientific resources to the study of those coronaviruses.
Although no bird-to-human transmissions of infectious bronchitis virus have been reported, there are similar human virus strains.
More importantly, however, potential human infection by the Beaudette strain of avian infectious bronchitis virus was demonstrated in the laboratory through viral adaptation by multiple passages of the virus in mammalian cell cultures.
That viral adaptation was attributed to the S2 subunit of the spike glycoprotein, in particular, the “Beaudette-specific motif,” containing the polybasic amino acid sequence of Arginine-Arginine-Lysine-Arginine beginning at the 686 positions.
It is well known that such proteases-sensitive, e.g. furin, polybasic cleavage sites play important roles in the pathogenicity of bird influenza and cat peritonitis coronavirus infections.
It may not be a coincidence that COVID-19 also has a polybasic cleavage site with a similar amino acid sequence of Arginine-Arginine-Alanine-Arginine inserted at position 682, reportedly near the S1-S2 junction of the spike glycoprotein, not at the S2′ location as previously stated.
COVID-19’s polybasic amino acid sequence does not occur in any of the yet identified naturally-occurring bat coronavirus “relatives” of COVID-19.
So, that unique feature of COVID-19 arose from a yet unknown and perhaps a statistically unlikely naturally-occurring recombinant event or by intentional genetic manipulation.
That is, a Chinese laboratory may have bioengineered a furin polybasic cleavage site into a bat coronavirus in order to study its effects on pathogenicity in the same way the “Beaudette-specific motif” was studied to determine the ability of avian viruses to infect mammals.
Let’s be clear, although the Chinese government, some Western scientists and the mainstream media have tried to stifle debate by insisting that COVID-19 was a naturally-occurring transmission from animals to humans originating in the Wuhan Seafood Market, so far, no one knows its origin.
There is no doubt that Chinese scientists have the knowledge and the techniques to manufacture new viruses by combining the properties of two or more viruses as “chimeras,” described in patent US9884895B2, and the animal models to test the ability of those new viruses to infect humans.
Given the illness, death and economic destruction caused by COVID-19, it is the responsibility of the Chinese government to fully open its research files and databases to international inspection, including information about the hundreds of coronavirus isolates it has stockpiled, in order to ascertain the true origin of the Chinese COVID-19 coronavirus.
This column was originally published at WION.
The views expressed in CCNS member articles are not necessarily the views or positions of the entire CCNS. They are the views of the authors, who are members of the CCNS.
