Lab-leak claims punctured

BEIJING/MEXICO CITY/MOSCOW－Scientists alarmed at the spread of conspiracy theories centered on the origins of COVID-19 have become louder in their denunciation of claims that the coronavirus leaked from a laboratory.

One such figure is David Robertson, a virologist with the University of Glasgow in Britain.

There is no evidence that SARS-CoV-2－the novel coronavirus behind the COVID-19 pandemic－was created in a lab, and none of the lab-leak claims "hold up to scientific scrutiny".

Such theories offer "no evidence other than the circumstantial location of the Wuhan Institute of Virology", which is in Wuhan, in Central China's Hubei province, Robertson, the head of viral genomics and bioinformatics of the Scottish university, said in an email interview recently.

"Currently, all of the data points strongly in one direction, and that's toward a natural virus, not one created in a lab," Robertson said. "We need to trust in the evidence and the experts who have experience of virus evolution and emergence."

The virologist also said it is "far too divergent" for RaTG13, a coronavirus detected in horseshoe bats in Southwest China's Yunnan province in 2013, to be the progenitor of SARS-CoV-2 that caused the first human cases, as the two viruses differ in about 1,100 nucleotide positions.

"That the closest bat viruses to SARS-CoV-2 are found in Yunnan is misleading as there's a massive under-sampling issue and although these bat viruses are genetically close, this still represents decades of time," Robertson said.

No existing evidence

Robertson was among 21 eminent scientists from universities and research institutes around the world who have warned that a focus on a highly improbable lab origin of COVID-19 is distracting scientific tasks from comprehensively investigating the zoonotic origins of the virus.

The scientists, in a review paper on the origins of SARS-CoV-2 published in July as a preprint on Zenodo, an open-access repository, wrote that no evidence exists for the claim that the virus originated from a lab and that "there is no evidence that any early cases had any connection to the Wuhan Institute of Virology".

Commenting on the renewed interest in the lab-leak theory in the United States over recent months, he said: "It's really hard to understand how this happened, there was no new data presented."

He added: "I'd say the main one is it stops being science anymore."

Didier Pittet, an infectious diseases expert at Geneva University Hospitals, echoes his view.

The accusation over a lab leak in Wuhan is "more political in nature", said Pittet, who pointed to the absence of evidence in an interview with Russia's Sputnik news agency published late last month.

People often forget that the first destructive bacteria escaping from a laboratory happened in the United States, he noted.

Gabriel Gras, a French biosecurity expert, likewise dismissed the lab-leak claims as "not credible".

The expert had monitored the construction of the Biosafety Level 4 Laboratory of the Wuhan institute.

Biosafety Level 4 is the highest level to provide necessary precautions from pathogenic microbes.

The lab "was built under the close cooperation between China and France", and "there is no doubt about its compliance with the highest international biosafety standards," Gras said.

The construction and operation of the lab conform to very strict standards, he said.

He also noted that coronaviruses, including SARS-CoV-2, don't "need to be dealt with in a BSL-4 lab", considering the high cost of operating such a facility.

Xinhua