A group of researchers working at Boston University have created a new type of SARS-CoV-2, the virus that causes COVID-19, that is far more virulent than any previous strain.
According to their research, which was published on the biology preprint server bioRxiv on Friday and has not been peer-reviewed, the scientists combined two variants by placing the spike protein used by the Omicron variant onto the virus of the original SARS-CoV-2 strain seen in Wuhan in late 2019. The spike protein is the device the virus uses to enter a cell it is attacking, and Omicron’s evolved spike protein is far better at doing so than earlier variants, enabling it to evade immune defenses created in response to prior infection or vaccination.
The resulting viral strain was unlike anything scientists have seen before. According to their research, while the regular Omicron strain caused “mild, non-fatal infection” in all mice it was tested on, the mutant variant “inflicts severe disease with a mortality rate of 80%,” they said.
In the Wuhan variant, mortality was less than 2%, according to Johns Hopkins University data, although in some environments, such as New York, where hospitals overflowed with patients in the spring of 2020, mortality reached 10%.
The scientists’ mutant variant was also found to be five times more infectious than Omicron, the most infectious of any SARS-CoV-2 variant and the one responsible for most infections around the globe this year.
However, the scientists caution that their hybrid variant is unlikely to be as deadly for humans as it is for mice, because of significant differences between immune responses in the two species.
Probing Covid’s Methods
The scientists said their goal was to investigate the role the spike protein plays in overall pathogenicity, or its ability to cause a disease. The research may provide new ways to design antibodies to better treat or prevent infection by the Omicron variant.
“We show that spike, the single most mutated protein in Omicron, has an incomplete role in Omicron attenuation,” they said. “This suggests that mutations outside of spike are major determinants of the attenuated pathogenicity of Omicron.”
Part of this owes to the fact that the Wuhan strain prefers to replicate in lung alveoli or the little sacks inside the lungs that fill with air when you inhale. However, Omicron prefers to infect the bronchioles, or branch-like pathways that connect the alveoli to the throat, replicating much more poorly in the deeper parts of the lung.
Screengrab of Russian Defence Ministry briefing showing US-sponsored biolabs on Ukraininan territory.
© Photo : Russian Ministry of Defence
Worries Over US Biolabs
The work was performed at BU’s National Emerging Infectious Diseases Laboratories, one of 13 biosafety level 4 labs in the US. Such labs are the only ones authorized to handle the world’s most dangerous pathogens, such as Ebola, Marburg, avian influenza, and extinct viruses such as Variola (smallpox) and rinderpest.
Such labs are commonly used to investigate ways to treat related diseases or to devise defenses against potential bioweapons. However, there have been increasing worries about the use of such labs to create weapons themselves, or for the pathogens to be improperly handled. A group of US biolabs discovered in eastern Ukraine by Russian forces after Moscow launched its special operation in February is emblematic of such fears.
It’s highly ironic that BU would be handling SARS-CoV-2 in such a way, given how Washington has tried to blame China for the COVID-19 pandemic by suggesting the virus had escaped from the Wuhan Institute of Virology. Former US President Donald Trump accused Beijing of doing so deliberately as a way to undermine the United States, which US President Joe Biden ordered the US intelligence community to produce a report on the origins of SARS-CoV-2.
After months of research, the Office of the Director of National Intelligence (ODNI) arrived at the same conclusions as the World Health Organization (WHO), and vindicated China’s position: the virus most likely entered humans via a natural zoonotic encounter with a host species, likely a type of bat or pangolin, was not a bioweapon, and was not being studied at the Wuhan institute prior to the outbreak.
