New Report Debunks COVID-19 Conspiracy Theories
The novel coronavirus is not a “laboratory construct” but the result of natural evolution
Ever since the novel coronavirus began sweeping the globe, misinformation has spread just as quickly. Accusations have been made by politicians in both the United States and China that the COVID-19-causing coronavirus (SARS-CoV-2) may have been manufactured in a laboratory. According to the results of a new article published in Nature Medicine, the new coronavirus is not a “laboratory construct or a purposefully manipulated virus” but emerged as a result of natural evolution. This most recent report helps clear up some of the confusion surrounding the origins of the disease.
Earlier this year, a preprint published online on the bioRxiv platform had suggested that the novel coronavirus was lab-created based on “uncanny” similarities between the new virus and human immunodeficiency virus (HIV) that were “unlikely to be fortuitous in nature.” The scientific community swiftly criticized the methods as rushed (based on a poor understanding of pBLAST) and the findings as coincidental at best. The paper was later retracted, but the damage had already been done.
The coronavirus family includes the virus responsible for the common cold as well as the more deadly viruses responsible for SARS (severe acute respiratory syndrome) and MERS (Middle East respiratory syndrome). This novel strain (SARS-CoV-2) causes a disease whose official name is COVID-19. ‘CO’ stands for corona (Spanish for “crown”) because this viral family expresses spikes on their cell surfaces (not because of any relation to a popular Mexican beer), ‘VI’ stands for virus, ‘D’ stands for disease, and ‘19’ refers to the year in which it was identified. The naming scheme deliberately avoids mentioning any particular geographic location in order to minimize stigmatization. Unfortunately, these efforts are unlikely to reduce the incidence of xenophobia in our current cultural climate.
Strong clues suggesting the disease’s zoonotic origins had already begun to emerge in late February when a perspective piece published in the New England Journal of Medicine explained,
“Scientists tell us that SARS-CoV-2 did not escape from a jar: RNA sequences closely resemble those of viruses that silently circulate in bats, and epidemiologic information implicates a bat-origin virus infecting unidentified animal species sold in China’s live-animal markets.”
The latest correspondence letter in Nature Medicine describes how researchers went about analyzing the genetic sequences that encode for the protein spikes expressed on the surface of SARS-CoV-2. The virus seems to resemble a medieval mace with multiple spikes emanating from its spherical body. The virus uses these spikes in order to invade and infiltrate host cells.
According to researchers, the fact that SARS-CoV-2 binds the human receptor ACE2 with high affinity makes it highly unlikely to have been manufactured by humans with existing technology. The genetic sequence that encodes for the receptor-binding domain (RBD), a kind of grappling hook that grips onto host cells, is very different than those predicted by computer analyses to ensure optimal binding. If the virus had been genetically manipulated, one of several known coronaviruses would likely have been used as a template. Lead author Kristian G. Andersen, Ph.D. of the Scripps Research Institute writes,
“The genetic data irrefutably show that SARS-CoV-2 is not derived from any previously used virus backbone.”
The structure of the SARS-CoV-2 RBD is unlike any that has been previously encountered in humans and instead resembles those found in bats and pangolins, armadillo-like mammals found in Asia and Africa.
Another characteristic of SARS-CoV-2 known as the cleavage site, a molecular can opener that allows the virus to crack open and enter host cells, is also observed in related coronaviruses in nature. Efficient cleavage of the MERS-CoV spike enables transmission from bats to humans. Similar cleavages sites to that of SARS-CoV-2 are also observed in strains of bird flu and can facilitate increased pathogenicity. SARS-CoV-2 may have evolved such a virulent cleavage site after jumping to humans, thereby becoming much more capable of spreading between people and kicking off the current pandemic.
Kristian Anderson, associate professor of immunology and microbiology, concludes,
“By comparing the available genome sequence data for known coronavirus strains, we can firmly determine that SARS-CoV-2 originated through natural processes.”
Dr. Josie Golding, epidemics lead at UK-based Wellcome Trust, said the findings by Andersen and colleagues are “crucially important to bring an evidence-based view to the rumors that have been circulating about the origins of the virus (SARS-CoV-2) causing COVID-19.”
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