The journal Nature reported in 2015 that American biologists have created a chimeric virus based on the bat coronavirus and the SARS virus that can infect humans. The experimenters themselves did not doubt the usefulness of the study, but other scientists called it dangerous, noting that the virus could "escape".
Published on November 12, 2015.
Editors Note, March 2020: We understand that this material is being used to advance unverified theories that the coronavirus causing COVID-19 is artificial. There is no evidence for this, and scientists believe that animals are most likely the source of the coronavirus.
An experiment to create a hybrid version of the bat coronavirus, linked to the virus that causes SARS (SARS - Severe Acute Respiratory Syndrome), has sparked new debate about whether it is worth the risk of laboratory-producing strains of viruses capable of causing pandemics.
In an article published November 9 in the journal Nature Medicine, scientists are analyzing the SHC014 virus found in China in horseshoe bats. The researchers created a chimeric virus based on the SHC014 surface protein and the internal constituent of the SARS virus, which they grew in mice to mimic human disease. The chimeric virus infected cells in the human respiratory tract, proving that the surface protein SHC014 has the necessary structure to attach to a key receptor on cells and infect them. It also caused disease in mice, but did not kill them.
Coronaviruses isolated from bats have failed to attach to a key human receptor. But in 2013, scientists reported that another coronavirus, taken from the same group of bats, could do it.
These findings reinforce suspicions that bat coronaviruses that can directly infect humans (without a developmental phase in the intermediate cells of the animal) may be much more common than previously thought.
However, other virologists doubt that the information obtained from the experiment justifies the potential risk. While the magnitude of any risk is difficult to assess, virologist Simon Wain-Hobson of the Pasteur Institute in Paris notes that scientists have created a new virus that “grows very well” in human cells. “If the virus escapes, no one can predict its trajectory,” he says.
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Chimera creation
This argument is essentially a reiteration of the debate about whether laboratory testing that enhances virulence, as quantification of the pathogenicity of a microorganism is called, should be allowed. In October 2014, the US government introduced a moratorium on federal funding for research into the viruses that cause SARS, influenza, and MERS (Middle East Respiratory Syndrome, a deadly disease caused by a virus that sometimes spreads from camel to humans).
When the moratorium was introduced, another study was already underway, and the National Institutes of Health allowed it to continue under departmental control, says infectious disease researcher Ralph Baric, who works at the University of North Carolina and who co-authored the study. Over time, the National Institutes of Health came to the conclusion that this work is not very risky, and it does not fall under the moratorium.
But Wayne-Hobson disapproves of this study, because it is of little benefit and has very little to say about the dangers posed to humans by the wild SHC014 virus found in bats.
Other experiments in this study show that the bat virus must evolve to pose a threat to humans. Such a change may never happen, although this also cannot be ruled out. Baric and his team recreated the wild virus from its genomic sequence and found that it does not develop well in human cell culture and does not cause serious disease in mice.
"The only result of all this work is the creation of a new, unnatural risk in the laboratory," says molecular biologist and biosecurity specialist Richard Ebright at Rutgers University in New Jersey. Ebright and Wayne-Hobson have long criticized this kind of research.
The study authors also acknowledge that future sponsors may seriously question the feasibility of such experiments. "Groups of scientific reviewers may find similar studies to create chimeric viruses from circulating strains too risky to continue," they write. "More discussion is needed on whether further research on chimeric viruses is worthwhile in the face of the risks they pose."
Useful research
However, Baric and other scholars say there are benefits to this work as well. She helped “move this virus from being a 'candidate for new pathogens' to being a 'direct and clear threat,' says Peter Daszak, who participated in the 2013 study. Dashak is President of the EcoHealth Alliance, an international scientific organization headquartered in New York. She collects virus samples from animals and humans at new infectious foci around the world.
Studies of hybrid viruses in human cell culture and in animal models have little to say about the threats posed by the wild virus, Dashak says. However, he notes that such studies help to clarify which pathogens require priority attention in future scientific work.
Baric said that if there is no experimentation, the SHC014 virus will not be considered a threat. Previously, scientists, based on molecular modeling and other studies, believed that he was not able to infect human cells. The latest work shows that this virus has already overcome critical barriers, having managed to attach to human receptors and quite successfully infect the cells of the human respiratory tract. “I believe this cannot be ignored,” says Baric. He plans to conduct new studies of the virus in primates, hoping that they will provide him with data useful to humans.
Original publication: Engineered bat virus stirs debate over risky research
Declan Butler