- University of Arizona evolutionary biologist Michael Worobey, who also signed the letter, said natural emergence is the most plausible explanation. But as someone who works with potentially dangerous viruses, he knows a laboratory leak is not out of the question.
It has happened before, he said, including in 1977 when a strain of flu apparently stored in a freezer for more than two decades somehow escaped and caused the so-called “Russian flu” epidemic in the former Soviet Union and China.
“It’s something I’ve been concerned about in my own lab for a long time,” Worobey said.
Even if a lab origin is ruled out for COVID-19 — which Worobey hopes will be the case — he believes the potential role of research facilities in spreading new pathogens deserves careful consideration in the future.