The pieces of the puzzle of covid-19’s origin are coming to light
"This work, results from which were also published in Nature Medicine, demonstrated that SARS-CoV’s jump from bats to humans had not been a fluke; other bat coronaviruses were capable of something similar. Useful to know. But giving pathogens and potential pathogens extra powers in order to understand what they may be capable of is a controversial undertaking. These “gain of function” experiments, their proponents insist, have important uses such as understanding drug resistance and the tricks viruses employ to evade the immune system. They also carry obvious risks: the techniques on which they depend could be abused; their products could leak. The creation of an enhanced strain of bird flu in 2011 in an attempt to understand the peculiar virulence of the flu strain responsible for the pandemic of 1918-19 caused widespread alarm. America stopped funding gain-of-function work for several years.

Filippa Lentzos, who studies biomedicine and security at King’s College, London, says the possibility of SARS-CoV-2 having an origin connected with legitimate research is being discussed widely in the world of biosecurity. The possibilities speculated about include a leak of material from a laboratory and also the accidental infection of a human being in the course of work either in a lab or in the field.

Leaks from laboratories, including BSL-4 labs, are not unheard of. The world’s last known case of smallpox was caused by a leak from a British laboratory in 1978. An outbreak of foot and mouth disease in 2007 had a similar origin. In America there have been accidental releases and mishandlings involving Ebola, and, from a lower-containment-level laboratory, a deadly strain of bird flu. In China laboratory workers seem to have been infected with SARS and transmitted it to contacts outside on at least two occasions.

A preprint published on ResearchGate, a website, by two Chinese scientists and subsequently removed suggested that work done there may have been cause for concern. This lab is reported to have housed animals—including, for one study, hundreds of bats from Hubei and Zhejiang provinces—and to have specialised in pathogen collection.

Richard Pilch, who works on chemical and biological weapons non-proliferation at the Middlebury Institute of International Studies, in California, says that there is one feature of the new virus which might conceivably have arisen during “passaging experiments” in which pathogens are passed between hosts so as to study the evolution of their ability to spread.

Many scientists think that with so many biologists actively hunting for bat viruses, and gain-of-function work becoming more common, the world is at increasing risk of a laboratory-derived pandemic at some point. “One of my biggest hopes out of this pandemic is that we address this issue—it really worries me,” says Dr Pilch. Today there are around 70 BSL-4 sites in 30 countries. More such facilities are planned."

https://www.economist.com/science-and-technology/2020/05/02/the-pieces-of-the-puzzle-of-covid-19s-origin-are-coming-to-light