SARS-CoV-2, the virus causing COVID-19, does not appear to be genetically engineered.

There continues to be a debate about the origin of SARS-CoV-2 virus. A recurring rumor is that this virus was “engineered by humans as a bioterrorism weapon,” that this was a part of “gain of function research” to “supercharge the virus” at the Wuhan Institute of Virology, and this work was funded by the NIH. These rumors were reiterated in an opinion piece in the WSJ yesterday that claimed “Science Suggests a Wuhan Lab Leak.” Despite what is presented in the article, science suggests, if anything, this virus actually arose in the wild.

The authors, two individuals who have no background in bio-defense or in genetics, claim that the genetic code of the virus reveals “purposeful manipulation.” They believe that the spike protein, which is how the virus binds human cells, was engineered and this was part of a “gain of function” research effort on the part of the Chinese at the Wuhan Virology Institute. Despite this, no part of the genetic sequence of this virus has not already been found in the wild, although never before together.

Recent scientific studies actually show that this virus probably developed the ability to infect humans while infecting bats and other species prior to jumping to humans. 

Several scientific groups examined the genetic sequence of coronaviruses isolated from bats and pangolins in different areas of Asia. What they found is a remarkable evolution of these viruses that eventually yielded a virus that could readily infect human beings.

The spike protein on the virus (red arms) binds to the ACE2 protein on respiratory cells to initiate COVID-19 infection.

One analysis focused on the gene sequence of the virus’ spike protein, which is the protein that binds to the ACE2 protein on humans cells and allows infection of cells lining the respiratory tract. When examining the spike protein sequence from different bats and pangolins in Asia, it becomes clear there were changes in the genetic sequence that markedly altered the ability of these viruses to infect different species. 

These viruses essentially split into two groups — one group that infected through the ACE2 protein (like SARS-CoV-2 in humans) and another group that appears to infect through another mechanism. This latter group of viruses, isolated initially from Cambodian bats, has a unique mutation in this region that prevents any binding to any ACE2 protein and likely causes no infection in humans. 

The ACE2 binding protein regions of the spike protein (Identified as RBD) are similar between SAR-CoV-2 and the Bat RaTG13 and GD pangolin viruses. This suggests these mutations first occurred in other animals.

In the ACE2 binding group of viruses there is evidence that these viruses evolved in several species of animals, and can infect many different animals. This indicates these viruses can bind to ACE2 proteins from many species. The fact that even SARS-CoV-2 binds efficiently to the ACE2 protein of several animal species would seem to invalidate concerns that the SARS-CoV-2 was purposely engineered for human ACE2 binding.

Bat, pangolin and human viruses bind to the human ACE2 protein. Therefore the bat and pangolin viruses can infect humans. In fact, the pangolin virus (orange line) binds to human cells better than SARS-CoV-2 (purple line)!

Unfortunately, this also suggests that the human ACE2 binding of SARS-CoV-2 is not entirely optimized for the human ACE2 protein binding. This suggests that new variants could become better at infecting humans through adaptive evolution as the virus spreads through the human population   

In addition, the mutations in the spike protein that facilitate binding to human ACE2 receptor are at four or five different points on the spike protein. This is nothing that could be modeled or even anticipated with human engineering or artificial intelligence. All of this together would suggest that this is not an engineered virus and was not purposely developed in a way to increase its potential to infect human beings.

In contrast to the authors’ opinion piece, engineering the spike protein would not have been the way individuals proceed with engineering “weaponized or supercharged” (authors words) viruses. Almost all known “gain of function research” involves inserting toxins or other genes that would make the virus more deadly and defeat immune protection against the virus. There are no sequences like this present in SARS-CoV-2. If anything, the virus is not debilitating in most young, healthy people. This makes the likelihood that this was an “engineered” virus almost nil.

While none of this precludes the concept that there was an accidental release of a natural virus from the Wuhan Virology Institute, trying to suggest that this was part of a purposeful engineering program, particularly one funded by NIH, is false narrative that detracts from the important discussions around the COVID-19 pandemic.

Trying to find the sources of the SARS epidemic is an important task, and the role of the Wuhan Virology Institute is important to investigate. However, making outlandish claims about genetic engineering and viral enhancement is not something that helps the process.

Published by jbakerjrblog

Immunologist, former Army MD, former head of allergy and clinical immunology at University of Michigan, vaccine developer and opinionated guy.

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