Published 17:53 IST, February 25th 2021
WHO team's doctor explains why COVID didn't leak from Wuhan lab, cites 'genetic evidence'
An Australian doctor who was part of the WHO team of experts that visited China’s Wuhan, Dominic Dwyer explained why COVID-19 was not leaked from the lab.
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An Australian doctor who was part of the World Health Organization (WHO) team that visited China’s Wuhan, Dominic Dwyer wrote in a first-person account explaining why the origin of the novel coronavirus, SARS-CoV-2 causing COVID-19 is unlikely to be either the seafood market in the city or leaked from Wuhan lab.
Arguing against major conspiracy theories claiming that the highly-infectious virus was leaked from a lab researching on pathogens, Dwyer described in an article published for The Conversation that when the team of international experts visited the closed market it was easy to see how the virus could have spread there. Even though the high number of infections in the different markets suggested transmission clusters, it further implied “unknown or unsampled chains of transmission”.
While describing his experience, Dwyer wrote, “When we visited the closed market, it’s easy to see how an infection might have spread there. When it was open, there would have been around 10,000 people visiting a day, in close proximity, with poor ventilation and drainage.”
“There’s also genetic evidence generated during the mission for a transmission cluster there. Viral sequences from several of the market cases were identical, suggesting a transmission cluster. However, there was some diversity in other viral sequences, implying other unknown or unsampled chains of transmission.” He concluded Wuhan seafood market as a hotspot that further led to the COVID-19 pandemic. “The market in Wuhan, in the end, was more of an amplifying event rather than necessarily a true ground zero,” he added.
Wuhan lab leak is also ‘extremely unlikely’
Further, in the lengthy explanation published on the site, the Australian scientist explained why the leak from the Wuhan lab is also “extremely unlikely”. He wrote that the team of international experts sent to Wuhan to investigate the origins of the novel coronavirus visited the lab in the centre of all theories, Wuhan Institute of Virology. After speaking to scientists working there, the experts found no evidence of coronavirus antibodies. The WHO team, as Dwyer explained, looked at the closest virus to SARS-CoV-2 that the researchers were working on in the lab, the virus RaTG13. However, all scientists had a genetic sequence for the virus and they had not been able to grow in culture.
Dwyer wrote, “We spoke to the scientists there. We heard that scientists’ blood samples, which are routinely taken and stored, were tested for signs they had been infected. No evidence of antibodies to the coronavirus was found. We looked at their biosecurity audits. No evidence.”
“We looked at the closest virus to SARS-CoV-2 they were working on — the virus RaTG13 — which had been detected in caves in southern China where some miners had died seven years previously. But all the scientists had was a genetic sequence for this virus. They hadn’t managed to grow it in culture. While viruses certainly do escape from laboratories, this is rare. So, we concluded it was extremely unlikely this had happened in Wuhan,” he summed up.
17:55 IST, February 25th 2021