The four endemic human coronaviruses HCoV-229E,-NL63,-OC43, and-HKU1 contribute a
considerable share of upper and lower respiratory tract infections in adults and children.
While their clinical representation resembles that of many other agents of the common cold,
their evolutionary histories, and host associations could provide important insights into the
natural history of past human pandemics. For two of these viruses, we have strong evidence
suggesting an origin in major livestock species while primordial associations for all four …