Timeline: How the Wuhan lab-leak theory suddenly became credible

The source of the coronavirus that has left more than 3 million people dead around the world remains a mystery. But in recent months the idea that it emerged from the Wuhan Institute of Virology (WIV) — once dismissed as a ridiculous conspiracy theory — has gained new credence.

How and why did this happen? For one, efforts to discover a natural source of the virus have failed. Second, early efforts to spotlight a lab leak often got mixed up with speculation that the virus was deliberately created as a bioweapon. That made it easier for many scientists to dismiss the lab scenario as tin-hat nonsense. But a lack of transparency by China and renewed attention to the activities of the Wuhan lab have led some scientists to say they were too quick to discount a possible link at first.

Sen. Tom Cotton (R-Ark.) from the start pointed to the lab’s location in Wuhan, pressing China for answers, so the history books will reward him if he turns out to be right. The Trump administration also sought to highlight the lab scenario but generally could only point to vague intelligence. The Trump administration’s messaging was often accompanied by anti-Chinese rhetoric that made it easier for skeptics to ignore its claims.