Bulletin of the Atomic Scientists reports:

Much remains uncertain about the new coronavirus. What treatments will prove effective against COVID-19? When will a vaccine for the disease be ready? What level of social distancing will be required to tame the outbreak, and how long will it need to last? Will outbreaks come in waves? Amid all these vital forward-looking questions remains a more retrospective but still important one: Where did SARS-CoV-2, the virus that causes COVID-19, come from in the first place? Experts seem to agree it wasn’t the product of human engineering. Much research has been focused on the hypothesis that bats passed a virus to some intermediate host—perhaps pangolins, scaly ant-eating mammals—which subsequently passed it to humans. But the pangolin theory has not been conclusively proven. Some experts wonder whether a virus under study at a lab could have been accidentally released, something that’s happened in the past.

Among the latest entrants to the debate about the provenance of SARS-CoV-2 are the authors of a March 17 Nature Medicine piece that takes a look at the virus’s characteristics—including the sites on the virus that allow it to bind to human cells. They looked at whether the virus was engineered by humans and present what appears to be convincing evidence it was not. They also considered the possibility that the outbreak could have resulted from an inadvertent lab release of a virus under study but concluded “we do not believe that any type of laboratory-based scenario is plausible.”

Not all experts agree.

Professor Richard Ebright of Rutgers University’s Waksman Institute of Microbiology, a biosecurity expert who has been speaking out on lab safety since the early 2000s, does agree with the Nature Medicine authors’ argument that the new coronavirus wasn’t purposefully manipulated by humans, calling their arguments on this score strong. Ebright helped The Washington Post debunk a claim that the COVID-19 outbreak can somehow be tied to bioweapons activity, a conspiracy theory that’s been promoted or endorsed by the likes of US Sen. Tom Cotton, Iran’s supreme leader, and others.

But Ebright thinks that it is possible the COVID-19 pandemic started as an accidental release from a laboratory such as one of the two in Wuhan that are known to have been studying bat coronaviruses. [Continue reading…]