• COVID-19 likely emerged in humans due to wildlife trade, similar to the 2002 SARS outbreak, based on virus evolution analysis.
• The study found that the virus traveled too quickly from its origin point (Western China or Northern Laos) to Wuhan for natural bat dispersal.
• Researchers determined the SARS-CoV-1 and SARS-CoV-2 viruses followed parallel paths, with viruses jumping from bats to wild mammals and then to humans in city markets.

A new study by researchers at UC San Diego School of Medicine and collaborators, published in Cell, suggests that the COVID-19 virus reached humans through the wildlife trade, mirroring the origin of the 2002 SARS outbreak. By analyzing the evolutionary history of sarbecoviruses, the researchers concluded that the virus's rapid spread to Wuhan was unlikely due to natural bat dispersal, pointing instead to the transportation of infected animals via the wildlife trade. This challenges the lab leak theory and highlights the role of human-animal interactions in zoonotic spillover events.

• What: A genetic study traces the origins of COVID-19, suggesting it emerged through the wildlife trade, similar to SARS.
• Who: Researchers from UC San Diego School of Medicine, University of Edinburgh, University of Arizona, and other institutions; Jonathan Pekar, Joel Wertheim, Michael Worobey, and Simon Dellicour are key researchers.
• When: The study was published on May 7, 2025; SARS outbreak in 2002; COVID-19 emergence in late 2019/early 2020.
• Where: Origin points in Western China or Northern Laos; emergence in Wuhan, China; SARS origin in Guangdong Province, South Central China.

The study provides compelling evidence against the lab leak theory by demonstrating that the emergence of COVID-19 closely mirrors the zoonotic spillover event that caused the SARS outbreak. By analyzing the genetic history of sarbecoviruses, researchers were able to show that the virus's rapid spread to Wuhan was unlikely through natural bat dispersal alone, supporting the role of wildlife trade in transporting the virus. The research highlights the risks associated with human-animal interactions and the importance of monitoring wild animal populations to prevent future pandemics. Although the intermediate host for SARS-CoV-2 remains unidentified, the study strengthens the understanding of how coronaviruses can jump from animals to humans.

When you sell wildlife in the heart of cities, you’re going to have a pandemic every so often.

There is nothing unique about how far SARS-CoV-2 had to travel to emerge in Wuhan. The SARS virus accomplished basically the same task via zoonotic emergence. Hence, there’s no need to invoke a 'lab leak' to explain the geography of SARS-CoV-2 emergence.

At the outset of the COVID-19 pandemic, there was a concern that the distance between Wuhan and the bat virus reservoir was too extreme for a zoonotic origin. This paper shows that it isn't unusual and is, in fact, extremely similar to the emergence of SARS-CoV-1 in 2002.

The recent genetic study reinforces the theory that the COVID-19 pandemic, similar to the SARS outbreak, likely originated from the wildlife trade. By tracing the evolutionary path of the virus and demonstrating its rapid spread across Asia, researchers have provided strong evidence against alternative origin theories, including the lab leak hypothesis. While the exact intermediate host remains unknown, the findings underscore the importance of regulating wildlife trade and preventing human-animal interactions to mitigate the risk of future zoonotic spillover events and pandemics. Ongoing research efforts are focused on identifying the missing links in the virus's evolutionary history and developing strategies to prevent future outbreaks.