For all the coronavirus.jhu.edu/map.html” target=”_blank”>human and economic damage that the novel coronavirus has caused, it remains a little-known enemy that continues to wreak havoc on countries across the world. There have been more questions than answers on practically every aspect of the crisis that it has unleashed but none that is more vexed perhaps as that regarding how it appeared suddenly on the scene.
There are two basic positions within the scientific community: the first, that it is undoubtedly the ‘spillover’ effect at work, the kind that occurs habitually, when an unknown pathogen lurking in nature finds the necessary genetic wherewithal to attack humans. Opposed to this view is the ‘lab leak’ argument that takes into account the clinical and physical circumstances surrounding the detection and spread of the novel coronavirus, or Sars-CoV-2, to say that the pandemic is a clear case of a man-made disaster.
In the early days of the pandemic, the second view was mostly considered to be a conspiracy theory propounded by rabble-rousing science sceptics or the Sinophobic camp. However, scientists have now come out to warn that the pursuit of the actual facts of the case should not be coloured by the politics of the moment and calls have been made to leave no stone unturned in investigating its origins. That’s because there are as yet no conclusive facts to support either the ‘spillover’ or ‘lab leak’ theories of the origin of the novel coronavirus. But with speculation about its origin proving at least as resilient as the virus itself, here’s a sampling of the claims that have driven the debate:
The virus escaped from a lab
At the centre of the pandemic, of course, stands Wuhan, the city in central China where the first cases of the new pathogen causing a pneumonia-like disease were reported in December 2019. And sharing the spotlight is the Wuhan Institute of Virology. Situated on the city’s hilly outskirts, it is one of the leading centres in the world doing advanced research on bat coronaviruses, the family to which the novel coronavirus belongs.
Virus research has evolved exponentially since the days of the earliest vaccines and labs today have the ability to manipulate and create new viruses with ease, often with the aim of making them more hazardous so that science can be one step ahead if a similar pathogen appeared naturally. Tests of this kind are called gain-of-function tests, that is, they involve engineering a virus to do things it is not naturally supposed to do.
And, that is where the question marks leap out. Shi Zhengli, a leading figure at the Wuhan institute, had been linked with similar gain-of-function experiments. So, if the Wuhan lab was indeed conducting gain-of-function experiments, did it specifically create a turbo-charged version of a coronavirus that managed to run amok after escaping its confines?
Just find the beast
Two outbreaks of infections caused by the family of coronaviruses in recent history are the 2003 Sars and the 2012 Mers epidemics. Both were cases of zoonotic transfer of the virus, that is, of the virus jumping from an animal host to humans. Since China said the first cases were reported at the Huanan seafood market in Wuhan and tests showed that the novel coronavirus was related to the family of bat coronavirus known as beta-coronaviruses, it was natural to explore the zoonotic infection theory.
The 2003 Sars and then Mers, both, were caused by beta-coronaviruses that emerged first in bats and then spread to humans via an intermediate host — civets cats in case of Sars and later through camels when it came to MERS. But here was another problem.
According to an article by former New York Times science writer Nicholas Wade published in the respected Bulletin of Atomic Scientists, it took scientists only four and nine months, respectively, to identify the intermediary host species for the Sars and Mers outbreaks. So, what’s taking scientists this long to figure out where Sars-CoV-2 came from?
Of chimeras and copy-pasted genes
While snakes and the pangolin have faced investigation, the lack of clinching evidence as to the intermediary host from whom Sars-CoV-2 jumped to humans is seen by ‘lab-leak’ supporters to be a strong hint that the ‘spillover’ theory cannot be taken at face value.
One way of proving that Sars-CoV-2 did indeed arise in nature and not in a lab would be to conclusively show that it is not humanly possible to create such a virus? But experts say that gain-of-function experiments and other innovations mean that it is technically possible to fashion viruses the likes of which exist nowhere.
The outbreaks of Sars and Mers meant that study of bat coronaviruses received priority among researchers everywhere including, but not limited to, the Wuhan lab. Now, the most relevant feature of the coronavirus are the spikes themselves that allow the virus to infect human cells. It has been claimed that the Wuhan institute was actively experimenting with spike proteins by combining genetic material from separate strains, creating what are known as ‘chimeras’. Interestingly, part of the evidence reportedly for such claims comes from the US itself.
A controversy has broken out that involves everybody from the country’s infectious diseases boss Anthony Fauci and well-known American virologists and is based on US funding of the Wuhan institute between 2014 and 2020, when the project was cancelled. While it is not clear that the US grants were specifically for gain-of-function tests, submissions to obtain these grants point to advanced experimentation with coronaviruses.
Among other arguments offered to bolster the lab leak theory is one that suggests Sars-CoV-2 broke on the scene rather like a well-honed invader that lost no time in racing through populations everywhere. The reasoning is that most RNA viruses, of which Sars-CoV-2 is one, are extremely careless replicators and hence have to go through multiple cycles of jumping hosts before a lucky break allows them to develop the genetic tools needed to catch a suitable host. There are a lot of variables involved and most viruses don’t make it to levels where they attract attention. Sars of 2002 and Mers did, but it was easy to find the trails they had left on their way to seizing human hosts. All of this would be perfectly understandable had there been animal or human populations detected close to the site of the first outbreak that were found to have played host to Sars-CoV-2 prior to its achieving wider circulation.
But Chinese authorities, or officials anywhere for that matter, have not been able to find records of infections caused by a similar pathogen. A strain remarkably similar to the novel coronavirus was, however, found in bat faeces collected from caves in China’s Yunnan province in 2013. The caves had been linked with a mysterious, but localised, outbreak where patients exhibited Sars-like symptoms. That eventually brought Shi Zhengli and her team from the Wuhan institute to the site, where they collected samples of bat faeces that they carried back for research and also shipped to other labs around the world.
When cases of the Sars-CoV-2 began to be reported, Shi Zhengli’s team found that its genome was a 96.2% match with another coronavirus known as RaTG13, which they had collected from the Yunnan caves. Although it was a close cousin, analysis showed that Sars-CoV-2 was not similar to the pathogen behind the localised outbreak linked to the caves. The ‘lab leak’ theorists suggested that couldn’t it be possible that the Yunnan bat samples that the Wuhan institute had been working on had first been ‘armed’ to better infect humans and then managed to slip out of the lab accidentally to start the pandemic?
The China wall and chinks in the armour
Labs around the world are notorious for leakages and accidents. Although the safety of such facilities are governed by strict compliances, human error can be discounted with difficulty even in laboratory settings. The Wuhan institute has a Biosafety Level-4 lab, but apprehensions have been expressed over the protocols followed by researchers there while handling deadly pathogens.
But all of it is easily verifiable, only if the will expressed internationally to crack the case did not have to contend with the wall of Chinese inscrutability. China has fiercely opposed any talk of the novel coronavirus having leaked from one of its labs and has been tight-lipped and cagey about attempts to ferret out clues. There have been question marks over the clean chit it was given following an on-the-ground inquiry by a World Health Organisation (WHO) team that concluded that the zoonotic spillover theory best explained the outbreak. Charges of conflict of interest have been made with respect to the composition of the team and it was also alleged that officials were only shown evidence that China wanted them to see and they had no scope to make an comprehensive assessment that would enable them to confidently exonerate Chinese officials.
A lot rides on the question of the origin of the novel coronavirus. But the waters are seemingly muddied by a collision of nationalistic sentiments, paranoia, competing interests and the fake news scourge of infodemic proportions. It is, however, for exactly these reasons that definitive answers are needed and measured voices have urged that it is important to look past the easiest explanations and politics of blame-shifting to arrive at conclusive proof that ties it all up.