Lab Leak or Animal Market?

Five years ago, I was visiting San Antonio when the first cruise ship passengers flew into nearby Lackland Air Force Base for quarantine. Seven million deaths later, there’s still no consensus on how the Covid pandemic began. Reputable scientists revised their hypotheses in light of fresh research. Politics muddied the waters. Laboratory leaks are real, though most viruses new to humans start as spillovers from other species. Bias is real too, though scientists have more guardrails than most of us against letting it shape their conclusions.

Newly appointed CIA Director John Ratcliffe announced in January that analysis of the limited data available pointed to a virology lab leak in Wuhan, China, as the source of Covid-19. The Department of Energy, the FBI, and the CIA all reached that assessment well before the current administration took office. I haven’t found details of their reasoning, for which they expressed “low confidence.”

Meanwhile, among scientific papers favoring the Wuhan seafood and animal market as the source, one published last September in the journal Cell intrigues me. The research team did genetic analysis of hundreds of environmental samples gathered in and near the market in early 2000. Samples of the new coronavirus were concentrated in the corner of the market with live wild animals, particularly raccoon dogs. Study of mutations gives evidence—but not proof—of when and how the virus spread, perhaps from bats to raccoon dogs to humans.

Proponents of both theories agree on one thing about how Covid-19 began in Wuhan: Nobody knows for certain.

​Images: (left) Raccoon dog, akin to foxes and named for its appearance; (right) Wuhan Institute of Virology, which studies coronaviruses in bats.