[5] HCoV-HKU1 was first detected in January 2004, in a 71-year-old man who was hospitalized due to acute respiratory distress syndrome and radiographically confirmed bilateral pneumonia.

[3][6] In 2023 according to the 2021 new binomial naming proposal, HCoV-HKU1 was renamed to Betacoronavirus hongkonense Woo and coworkers were unsuccessful in their attempts to grow a HCoV-HKU1 isolate but were able to obtain the complete genomic sequence.

Phylogenetic analysis showed that HKU1 is most closely related to the mouse hepatitis virus (MHV), and is distinct in that regard from other known human betacoronaviruses, such as HCoV-OC43.

[7] Additional research has revealed that the virus attaches itself to O-acetylated sialic acids on the cell surface,[8] which instigates a conformational shift in the S protein, facilitating interaction with the entry receptor.

[9] Intriguingly, the enzyme kallikrein 13 has been identified as an activating factor responsible for the spike protein processing by the Pyrc's team.

[10] When the RNA-dependent RNA polymerase (RdRp), spike (S), and nucleocapsid (N) genes were analyzed, incompatible phylogenetic relationships were discovered.

In these cases, French investigators utilized improved techniques for recovering the virus from nasopharyngeal aspirates and from stool samples.