Aug 5, 2025
The closest relative of OC43 is the bovine coronavirus, a pathogen that causes relatively mild respiratory disease in cattle. In turn, these two coronaviruses share a common ancestor with another virus that causes disease in pigs. All three shared an ancestor around two hundred years ago, when the branch that includes human and bovine coronavirus split apart.
"Plagues Upon the Earth: Disease and the Course of Human History" - Kyle Harper