Where the World’s at in the Hunt for the Origins of Covid-19

Scientists have yet to determine the origins of Covid-19, years after it touched off the worst pandemic in more than a century. Some of the closest related viruses to the one that causes it, SARS-CoV-2, were found in bats roughly 1,000 miles (1,600 kilometers) from the central Chinese city of Wuhan, where the disease erupted in late 2019. Initially, cases were tied to a fresh food market and possibly the wildlife sold there. An investigation in early 2021 highlighted the possibility that certain mammals acted as a vector, transferring the virus from bats to humans. There are more politically charged theories. One is that the virus accidentally escaped from a nearby research laboratory, a thesis underscored by the FBI in February. Another theory is that SARS-CoV-2 entered China from another country via imported frozen food. Amid all the posturing, governments and scientists agree that deciphering the creation story is key to reducing the risk of future pandemics.

Where, when and how a pathogen begins spreading in humans can be difficult, if not impossible, to pinpoint. Although SARS-CoV-2 is genetically similar to coronaviruses collected from bats, it may have followed a convoluted path to Wuhan, a city of 11 million people. Scientists are tracing the earliest known cases but the trail largely goes cold in early December 2019. Where a new disease starts spreading isn’t necessarily where it spilled over from the animal kingdom or first infected a human. HIV, for instance, is thought to have originated in chimpanzees in southeastern Cameroon. It didn’t begin spreading readily in people until the 1920s, when it reached the city of Kinshasa hundreds of miles away. Scientists reported that finding in 2014, some three decades after the AIDS pandemic was recognized.