Human coronavirus OC43

Human coronavirus OC43 (HCoV-OC43) is a member of the species Betacoronavirus gravedinis, which infects humans and cattle. The infecting coronavirus is an enveloped, positive-sense, single-stranded RNA virus that enters its host cell by binding to the N-acetyl-9-O-acetylneuraminic acid receptor. OC43 is one of seven coronaviruses known to infect humans. It is one of the viruses responsible for the common cold and may have been responsible for the 1889–1890 pandemic. It has, like other coronaviruses from genus Betacoronavirus, subgenus Embecovirus, an additional shorter spike protein called hemagglutinin-esterase (HE). ]. Genetic and antigenic analyses reveal significant similarities between HCoV-OC43 and bovine coronavirus (BCoV), suggesting a zoonotic transmission event from cattle to humans. Molecular analysis estimate that this cross-species transmission occurred sometime in the late 19th century, possibly around 1890. This period aligns with the "Russian Influenza" pandemic that occurred form 1889 -1892. This has led some researchers to theorize that HCoV-OC43 may have been the causative agent of that pandemic, rather than the influenza virus. This theory is further supported by phylogenetic studies indicating a recent common ancestor between HCoV-OC43 and BCoV around that time.