Thus far, researchers have not identified ancestral viruses that could have plausibly given rise to the SARS-CoV-2 virus that causes COVID-19—so says a new report from the Scientific Advisory Group for the Origins (SAGO) of Novel Pathogens set up by the World Health Organization (WHO).
The report, however, notes that "the current available data on the closest related SARS-like viruses and susceptibility of many animal species to SARS-CoV-2 suggest a zoonotic source." Assuming a natural outbreak, horseshoe bats are a likely reservoir of the virus in the wild, although it could also have passed through an unknown intermediate species before infecting humans.
