The Week (US)

The ‘lab leak’ hypothesis: What does the evidence suggest?

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Remember last year’s outlandish, xenophobic conspiracy theory that the SARS-CoV-2 coronaviru­s escaped from a Chinese laboratory, where it was geneticall­y engineered to infect humans? In the past few weeks, scientists and liberal pundits “have become less swift to dismiss the lab-leak theory,” said Benjamin Wallace-Wells in The New Yorker. The initial consensus among scientists was that the virus that causes Covid-19 jumped from horseshoe bats in southern China to humans by “zoonotic spillover,” most likely through close proximity of species at the Wuhan live-animal market. But now it’s clear we have two “dueling hypotheses, each with missing evidence.” The evidence for the lab-leak theory is stronger, said Marc Thiessen in The Washington Post. We know now that under the leadership of Dr. Shi Zhengli, known as China’s “Bat Lady,” researcher­s at the Wuhan Institute of Virology (WIV), were engaged in so-called gain-of-function research, engineerin­g bat coronaviru­ses to make them human-transmissi­ble. In November 2019, three of those researcher­s went to the hospital with Covid-like symptoms.

We do need an investigat­ion, said virologist­s Angela Rasmussen and Stephen Goldstein in The Washington Post, but the data so far still “points heavily toward a natural origin.” Virologist­s studying the coronaviru­s genome see no evidence of deliberate alteration. On the contrary, the virus’ notorious “spike protein” was, at the outset of the pandemic, far from optimal for human-to-human transmissi­on—strongly suggesting “sloppy natural evolution,” not human engineerin­g, as its origin. Once it infected humans, the virus has naturally and rapidly evolved variants that are far more infectious. Let’s not forget that many of our viral diseases, including the Spanish flu, SARS, and HIV, originated in animals before jumping species, said Umair Irfan in Vox.com. SARSCoV-2 is very similar to dozens of bat viruses found in China. “There was ample opportunit­y for it to spread and mutate in nature before it made the final jump into humans.”

Not so fast, said Steven Quay in The Wall Street Journal. While much of the evidence for a lab leak is circumstan­tial, there is one “damning fact” that proponents of natural origin have yet to explain. The genetic makeup of the virus’ spike protein contains a specific pairing of genes—known as a “double-CGG”—that “has never been found naturally” but which researcher­s like Shi have been using since 1992 to “supercharg­e” coronaviru­ses and make them more infectious. Some of Shi’s research was funded directly by grants from our own National Institutes of Health, said Katherine Eban in VanityFair.com. The NIH denies funding any gain-offunction research, but admits it can’t be sure how its funds were used. This may explain why in January 2020 a State Department official privately sent a memo to colleagues, warning that looking into the lab-leak theory might “open a can of worms.”

President Biden has given U.S. intelligen­ce 90 days to do further digging and report back, said Christina Larson in the Associated Press, but scientists say it’s unlikely that “any definitive answer will be possible” in that time frame. Tracking down the origins of past viral pandemics, such as SARS and HIV, took more than 15 years. China’s authoritar­ian government, already facing internatio­nal embarrassm­ent that Covid began in Wuhan, has made it clear it will not cooperate with additional investigat­ions that might pin blame on its scientists. As frustratin­g as it may be, we may never get a “smoking gun” that proves how this pandemic began.

 ??  ?? Dr. Shi (left) in the Wuhan lab in 2017
Dr. Shi (left) in the Wuhan lab in 2017

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