ウイルス学：2019年の新型コロナウイルスの命名

The statement announcing the name of the novel coronavirus currently causing an outbreak of respiratory disease, as designated by the Coronaviridae Study Group of the International Committee on Taxonomy of Viruses, is published in Nature Microbiology today. The virus has been named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), owing to its close genetic relatedness to viruses in a species prototyped by SARS-CoV. The paper describes the process involved in naming viruses, identifies potential causes of confusion over the nomenclature and highlights the importance of careful characterization of emerging viruses.

The established practice for classification of a new virus is to assess its genetic relation to known viruses. There are currently 39 recognized and 10 tentative coronavirus species, many of them containing dozens or even hundreds of different viruses. John Ziebuhr, Alexander Gorbalenya and colleagues assess how closely the novel coronavirus is genetically related to these known coronaviruses. By comparing genomic data and specifically looking at variation in conserved proteins involved in virus replication, they find that the novel virus clusters with viruses of the species Severe acute respiratory syndrome-related coronavirus. This relationship has also been reported by other groups and is so close that the virus could be classified as belonging to this previously established species rather than representing a new species. The novel virus has therefore been assigned the name SARS-CoV-2 based on these identified genetic links with viruses of the species Severe acute respiratory syndrome-related coronavirus.
The species itself derived its name from the founding virus responsible for the 2002 - 2003 respiratory disease outbreak in humans: SARS-CoV, whose name, in turn, was based on the name given to the associated disease SARS.

Severe acute respiratory syndrome-related coronavirus is a species that contains hundreds of known viruses (predominantly isolated from humans and bats), all of which have their names derived from SARS-CoV. However, the authors explain that the reference to SARS in these names acknowledges the evolutionary links - rather than the clinical disease-based relationship - with the founding virus.

Currently available data characterizing SARS-CoV-2 indicate that the disease traits and transmission may vary from those reported for SARS-CoV. The authors propose that the emergence of SARS-CoV-2 should be considered completely independent from the SARS-CoV outbreak in 2002 - 2003. However, they emphasize that the two viruses are genetically closely related, and recommend studying the relationships of viruses within this species to help us to understand more about the biology and evolution of these human pathogens and their closest coronavirus relatives infecting bats and other animals.

The WHO assigned the name COVID-19 to denote the disease that is caused by SARS-CoV-2, which appears to be associated with a wide range of clinical features and outcomes. This uncoupling of disease and virus name offers a clear distinction between the virus and disease; the authors recommend not conflating the terms when referring to the viral outbreak and the clinical disease.

Springer Nature is a signatory on a joint statement committing to the sharing of research data and findings relevant to the novel coronavirus outbreak. More information is available here and on the Nature Research press site.