SARS-CoV-2 Probably Leaked from a Lab


There is a growing body of evidence that suggests SARS-CoV-2 may have leaked from a lab, most likely the Wuhan Institute of Virology (WIV). While this hypothesis was initially dismissed by some journalists as a “fringe theory,” it has gained traction in recent years, with several intelligence agencies including the FBI and the Department of Energy considering it as a plausible explanation. It is important to note that there is no reason to believe the outbreak was intentional. In this post, I will examine the evidence supporting the lab leak hypothesis and address some of the counterarguments in favor of a natural origin.

Reasons to consider a lab leak hypothesis

1. The Wuhan Institute of Virology partook in risky research on bat coronaviruses

One of the main reasons to consider a lab-origin hypothesis is the fact that the WIV, the largest sarbecovirus lab in the world and located in the same city where the pandemic began, is known to have participated in risky gain-of-function research with viruses similar to SARS-CoV-2 in the years leading up to the pandemic.

Gain-of-function research refers to any type of research that alters a virus in an attempt to increase transmissibility, which ideally allows researchers to predict emerging diseases and develop vaccines and treatments more quickly. However, this kind of research is highly controversial, because it risks becoming the cause of a pandemic in the first place.

For more information on the WIV’s research practices, see here. From Butler (2015):

2. SARS-CoV-2 has a furin cleavage site

SARS-CoV-2 is the only known sarbecovirus of 1,535 such viruses to have a furin cleavage site (FCS):

Researchers had inserted cleavage sites into similar viruses, and the result was a significant increase in transmissibility. While it’s not impossible that this FCS could have arisen naturally, it’s still an important piece of evidence to consider, especially given that the insertion of an FCS into sarbecoviruses was explicitly proposed in 2018 by a partnership the WIV was a part of:

3. The WIV’s lack of transparency

The WIV has been less than transparent concerning the viruses it was working with leading up to the outbreak of COVID-19. Its database of viruses was taken down – with no explanation – and its contents still have not been released. There is also reason to believe the situation in Wuhan as of December 2019 was much worse than what is reported by Chinese officials. If it were true that the WIV had never encountered SARS-CoV-2 until the pandemic began, then the WIV could easily clear its name by cooperating with an investigation, but they have been hesitant to do so.

4. The absence of bats and pangolins in the Huanan Seafood Market

The most commonly proposed natural origin explanation is that SARS-CoV-2 jumped from animals to humans via the wildlife trade, which is why the original cases were found near the Huanan Seafood Market. However, there were no bats or pangolins in the Huanan Seafood Market. The closest wild bat populations to the city are ~1000km away. WIV researchers had to take trips to southern China to study this family of viruses.

In fact, Chinese officials could not find a single trace of SARS-CoV-2 in 80,000 wildlife they examined, which would be highly unlikely given a natural origin.

The animal and environment working group reviewed existing knowledge on coronaviruses that are phylogenetically related to SARS-CoV-2 identified in different animals, including horseshoe bats (Rhinolophus spp) and pangolins. However, the presence of SARS-CoV-2 has not been detected through sampling and testing of bats or of wildlife across China. More than 80,000 wildlife, livestock and poultry samples were collected from 31 provinces in China and no positive result was identified for SARS-CoV-2 antibody or nucleic acid before and after the SARS-CoV-2 outbreak in China. Through extensive testing of animal products in the Huanan market, no evidence of animal infections was found.

5. China’s response to the pandemic

Chinese officials, who are known for their draconian measures with respect to COVID-19, are not behaving as one would expect if they believed in a natural origin from bats to humans. For example, bat cave tourism is still active, and water is still pumped from caves for residential use. On the other hand, they are highly defensive and obstructive when it comes to any investigation into the WIV. China also began stockpiling and restricting the export of masks and other protective equipment months before the outbreak (around the same time the WIV’s database was taken down), which calls into question their official timeline of events.

Addressing counterarguments

While the evidence presented above supports the lab leak hypothesis, it is important to acknowledge and address some of the main counterarguments in favor of a natural origin:

  1. Previous coronavirus outbreaks had natural origins: Both SARS and MERS, two other coronaviruses, were traced back to natural origins in animal markets. This has led some to argue that it is more likely that SARS-CoV-2 also emerged naturally. However, the lack of a clear animal host and the unique features of SARS-CoV-2, such as the furin cleavage site, make it difficult to draw a direct comparison with these previous outbreaks.

  2. No direct evidence of a lab leak: Critics of the lab leak hypothesis argue that there is no direct evidence linking the WIV to the outbreak of COVID-19. While this is true, the circumstantial evidence presented above, combined with the lack of evidence for a natural origin, makes the lab leak hypothesis a highly plausible explanation that warrants further investigation.

  3. Viruses can evolve rapidly in nature: Some argue that the unique features of SARS-CoV-2, such as the furin cleavage site, could have evolved naturally through rapid mutation and recombination events in animal hosts. While this is a possibility, the fact that SARS-CoV-2 is the only known sarbecovirus with a furin cleavage site, combined with the WIV’s research on gain-of-function and the absence of a clear intermediate host, makes the lab leak hypothesis a more compelling explanation.

Conclusion (and why this matters)

While the lab leak hypothesis remains a subject of debate, it is crucial to consider all available evidence and engage in open, objective discussions about the origins of the pandemic. The growing support for the lab leak hypothesis among experts and intelligence agencies highlights the importance of questioning establishment narratives, especially when the issue is politically charged.

In retrospect, it seems that the dismissal of the lab leak hypothesis as a “fringe theory” in the early stages of the pandemic may have been premature. As more evidence emerges, it is essential to reassess our understanding of the origins of COVID-19 and learn from this experience to better prepare for and prevent future pandemics.