Illustration: Liu Rui/GT

In an exclusive interview with the Global Times, Liang Wannian, the Chinese leader of the WHO-China joint expert team, denounced the lab leak hypothesis put forward by some politicians under the continuing US-led politicization of the SARS-CoV-2 origins tracing, saying that some who insist on the hypothesis have mixed personal feelings or personal subjective judgments. 

When evaluating each hypothesis, we listed the arguments in support of this hypothesis and against this hypothesis, Liang said, noting that based on these arguments and evidence, experts evaluated them again.

"Regarding the lab hypothesis, we listed the evidence supporting laboratory leaks: We have seen lab leaks of viruses in other parts of the world in the past. But we still have a lot of evidence against this hypothesis," he said. 

According to the Chinese scientist, the lab hypothesis includes two parts; one is man-made; and the other is lab leak. The first one was ruled as impossible by scientists. About the other one, a basic premise of a lab leak is that the Chinese lab had previously stored the virus, Liang said. 

Experts from the WHO-China joint expert team visited the Wuhan Institute of Virology (WIV) and its P4 laboratory during their visit to Wuhan, Central China's Hubei Province, earlier this year, and discussed the lab hypothesis with the management and staff of WIV, Liang said, noting that experts also carefully discussed their research on the bat-related coronavirus and other advanced research project. 

"The joint expert group agreed that it's impossible that the virus was leaked from that lab," he said, as the lab has strict management and has not carried out research on this virus; from the published research, there is no virus close to it.

The 90-day investigation conducted by US intelligence agencies on the origins of the SARS-CoV-2 failed to reach any concrete conclusion, and they remained split on whether the virus came from natural origins or a lab-related incident. The WIV has been put under the spotlight by US politicians and media outlets as they promulgate the lab leak hypothesis. 

When the WHO-China joint team evaluated these hypotheses, it adopted a systematic approach and analyzed them in a rational way, Liang told the Global Times. Some people have mixed personal feelings or personal subjective judgments, probably citing the incidents of lab leaks in certain countries, or some people have made mistakes while working in labs, so they presumed that the SARS-CoV-2 was leaked from the lab. "I think it's totally unreasonable."

We speak with facts, and science speaks with evidence, the Chinese scientists said. The conclusion of this joint study is clear that "it is extremely unlikely" that the virus was introduced through a laboratory incident.