In the ongoing game of coronavirus-based conspiracy theory whack-a-mole, yet another seemingly credible claim that the virus behind the COVID-19 pandemic was manufactured in a lab has surfaced, this time from a study that claimed that the virus showed signs of being deliberately tampered with. The study was widely criticized due to fundamental flaws that were found in its methodology—not to mention a potential financial conflict of interest on the part of the author—and the paper’s conclusion has since been amended to reflect the corrections. But how do researchers know that SARS-CoV-2 acquired its ability to infect human hosts through a natural mutation, as opposed to having been genetically altered by scientists in a lab?
Since the sudden emergence of the SARS-CoV-2 coronavirus in China late last year, researchers have been studying every possible aspect of the virus in an attempt to further our understanding of the pathogen; the ease of its ability to spread, the (previously) seemingly random susceptibility of individuals to the disease’s effects, where it might crop up next, and just as importantly, where it came from.
Before 2000, the research community paid little heed to coronaviruses in general, since they had little effect on human health beyond causing mild cold-like symptoms. This attitude changed in 2002 when the SARS outbreak sickened 8,422 people and killed 774, prompting a dramatic increase in research into this previously-benign group of RNA viruses. This research revealed that SARS itself originated from a cluster of coronaviruses carried by horseshoe bats found across southern and central China, animals that were being sold in wet markets around the country.
The closest known relatives of both SARS-CoV-1 and SARS-CoV-2, the viruses that cause SARS and COVID-19, respectively, are also found in bats that inhabit China and neighboring countries, and have been well documented by research by organizations like EcoHealth Alliance over the past two decades.
“Our 15 years of work in China now puts us in a unique position to identify, with a remarkable degree of confidence, the likely origin of Covid-19,” according to EcoHealth president Peter Daszak. “We recently published a peer-reviewed paper reporting 781 genetic sequences of bat-origin coronaviruses previously unknown to scientists. These include the closest known relatives to Sars-CoV-1, Sars-CoV-2 and Sads-CoV, a virus that killed more than 25,000 pigs in Guangdong in 2016 and 2017. All are carried by horseshoe bats that are found across southern China and neighboring countries.”
In an editorial published in The Guardian, Daszak explains that claims that portions of the coronavirus’ genetic code were “inserted” artificially are undermined by the existence of another virus that is closely related to SARS-CoV-2—a virus found only in wild bats—that sports the same mechanism as its COVID counterpart.
Daszak also goes on to say that his organization’s epidemiology research also reveals that the spread of COVID-19 follows a natural pattern, rather than one that would be expected from an artificial release, accidental or otherwise. Using the results of a 2018 survey, they found that 3 percent of the residents in rural areas of China’s Yunnan province had antibodies for bat coronaviruses; extrapolating from that, the group estimates that somewhere between one and seven million people are infected with these bat-borne coronaviruses each year.
“Contrary to the idea that Chinese scientists deliberately released the virus, existing patterns of infection suggest that the wide spread of Covid-19 was a question of when, not if,” according to Daszak, stressing that as humanity’s exposure to these viruses increases, so does the risk of deadly outbreaks and pandemics.
EcoHealth isn’t alone in their assessment that the coronavirus is the result of a natural mutation: a study published by Scripps Research on the molecular makeup of SARS-CoV-2 found that computer modeling of the mutations that would be required to change the original SARS coronavirus into COVID-19’s present form continually produced a virus that didn’t bind to human cells very well, a trait that would prevent them from infecting its host. The researchers concluded that if tools available to human scientists indicate that altering a virus already known to be deadly to humans won’t result in a viable pathogen, then why make the attempt to begin with?
Additionally, SARS-CoV-2’s overall molecular structure—its molecular “backbone”—is more closely related to otherwise harmless coronaviruses naturally found in bats than its SARS-causing counterpart, so this reinforces the idea behind the natural mutation theory: why would someone use a harmless virus as the base for building a deadly one, when there are more lethal versions that already exist—and ones that would be rendered harmless by genetically editing them to begin with?
“These two features of the virus, the mutations in the RBD portion of the spike protein and its distinct backbone, rules out laboratory manipulation as a potential origin for SARS-CoV-2,” according to Scripps Research associate professor of immunology and microbiology Kristian Andersen, PhD.
This RBD, or receptor binding domain, is part of the mechanism at the end of the virus’ spike protein, an arrangement of molecules that allow the surface of the spikes to latch on to receptors found on the surface of cells in the human body called angiotensin-converting enzyme 2 (ACE2). Essentially, at some point the spike protein’s molecular “key” mutated to fit the “lock” of the ACE2 receptor’s molecular structure. But it didn’t do so in an efficient manner: Andersen’s team found that this molecular fit is imperfect, another possible indicator that the coronavirus is the result of natural evolution: if it were being deliberately altered by a human, its designer would likely make the RBD site more compatible with the target receptors, to ensure the outcome of a more deadly bioweapon.