Well over a year since a novel coronavirus began to spread in Wuhan, the idea that the deadly outbreak could be linked to a virus research center in the Chinese city has lingered, unproven but not eliminated.
Although the resurgent chatter may suggest new clues or proof, the inverse is in fact true. It is the persistent absence of any convincing evidence either for or against the theory that has prompted calls for more investigation.
At least publicly, the evidence in favor of a link between the outbreak and the Wuhan Institute of Virology (WIV) has not changed significantly in months, and many virologists still have persistent doubts that such a link exists.
What has clearly changed, however, is the political debate. Most obviously, a new U.S. administration that is not so openly anti-China has led some former skeptics to reconsider the existing evidence. And public health experts — most of whom never ruled out the lab theory outright — have expressed disappointment with a World Health Organization-backed investigation that dismissed a link between WIV and the outbreak.