MIT Technology Review has published an interesting story spelling out exactly what the Wuhan Institute of Virology was doing with bat viruses over the past few years. It’s interesting because this story really explains how the WIV was essentially taking US know-how and running experiments at much lower safety levels in order to make progress more quickly. It started when top American coronavirus expert Ralph Baric spoke to Dr. Shi Zengli:

In 2013, the American virologist Ralph Baric approached Zhengli Shi at a meeting. Baric was a top expert in coronaviruses, with hundreds of papers to his credit, and Shi, along with her team at the Wuhan Institute of Virology, had been discovering them by the fistful in bat caves. In one sample of bat guano, Shi had detected the genome of a new virus, called SHC014, that was one of the two closest relatives to the original SARS virus, but her team had not been able to culture it in the lab.

Baric had developed a way around that problem—a technique for “reverse genetics” in coronaviruses. Not only did it allow him to bring an actual virus to life from its genetic code, but he could mix and match parts of multiple viruses. He wanted to take the “spike” gene from SHC014 and move it into a genetic copy of the SARS virus he already had in his lab. The spike molecule is what lets a coronavirus open a cell and get inside it. The resulting chimera would demonstrate whether the spike of SHC014 would attach to human cells.

Baric’s concern was that there was the potential for a serious coronavirus outbreak which the world wasn’t ready for. The arrival of SARS in 2002, followed by MERS, proved the potential for novel versions of these viruses to be very deadly to humans. Baric wanted to find vaccines which could be effective against entire categories of coronaviruses.

In 2015 he published the results of his research which was titled “A SARS-like cluster of circulating bat coronaviruses shows potential for human emergence.” Contained in that paper was a detailed description of all of the additional precautions his lab had taken to make certain no virus would escape the lab:

In Baric’s lab, the chimeras were studied at BSL-3, enhanced with additional steps like Tyvek suits, double gloves, and powered-air respirators for all workers. Local first-responder teams participated in regular drills to increase their familiarity with the lab. All workers were monitored for infections, and local hospitals had procedures in place to handle incoming scientists. It was probably one of the safest BSL-3 facilities in the world. That still wasn’t enough to prevent a handful of errors over the years: some scientists were even bitten by virus-carrying mice. But no infections resulted.

Baric shared his work and his techniques with the WIV. He even sent them the humanized mice that had been used in his research. And at that point the piece indicates it became a kind of race with the WIV rushing to prove it could discover and study the most coronaviruses. Some of that research was funded by EcoHealth Alliance run by Dr. Peter Daszak. By 2016, Daszak and Dr. Shi were publishing papers using their own reverse genetics techniques:

Daszak and Shi published a paper reporting how the Chinese lab had engineered different versions of WIV1 and tested their infectiousness in human cells. The paper announced that the WIV had developed its own reverse-genetics system, following the Americans’ lead. It also included a troubling detail: the work, which was funded in part by the NIH grant, had been done in a BSL-2 lab. That meant the same viruses that Daszak was holding up as a clear and present danger to the world were being studied under conditions that, according to Richard Ebright, matched “the biosafety level of a US dentist’s office.”

Ebright believes one factor at play was the cost and inconvenience of working in high-containment conditions. The Chinese lab’s decision to work at BSL-2, he says, would have “effectively increas[ed] rates of progress, all else being equal, by a factor of 10 to 20”—a huge edge.

And that’s what has caused some scientists to reassess their view of the lab leak theory. Dr. Baric still believes the virus likely arose by jumping from a bat or other animal directly to humans, but the fact that this research was taking place at BSL level 2 and not with all the additional safety precautions used by his lab worries him. Maybe it didn’t happen this time but running these experiments at BSL-2 is taking a risk. “If you study a hundred different bat viruses, your luck may run out,” he said.

In May, Dr. Baric added his name to a letter in the journal Science calling for an investigation of the WIV and the lab leak theory. Again, it’s not that he believes a lab leak is the most likely scenario it’s just that he knows enough not to rule it out at this point.