On March 2, the International Committee on Viral Classification (ICTV) Coronary Virus Research Group published a paper in the journal Nature Microbiology, officially naming the new coronavirus “SARS-CoV-2”. The publication of the paper also means that the new coronavirus has a uniform name in the classification. However, the WHO and many domestic scholars have questioned the name.
So, how did the name SARS-CoV-2 come about? Why is it so close to SARS-CoV in name?
Writing by Yang Xinzhou
WHO Naming Principles
As early as February 11, the World Health Organization announced that the new coronary virus infection caused by pneumonia named “COVID-19.” However, COVID-19 is simply a name for the disease, not a new coronavirus that causes the disease. Also on February 11th, the International Viral Classification Commission’s Coronary Virus Research Group published a paper on the pre-printed website saying that the new coronavirus should be named SARS-CoV-2 according to the classification naming rules.
The starting point for naming the two organizations is not wrong, regardless of the name of the virus, and the difference is that the two organizations differ in the requirements for naming viruses. The World Health Organization, which is usually responsible for naming diseases caused by viruses, follows the following principles: Diseases do not refer to a particular person, population, or geographic location. In the naming principle, the WHO makes clear some examples that should be avoided, such as MERS (MERS), Spanish Flu (Spanish flu), lyme disease (Lyme disease).
In addition, specific animal names or industries should not be included in disease names, such as Swine flu (swine flu). Crucially, the new virus and the name of the disease cannot cause a clear public panic, which is why the World Health Organization has previously refused to name the new coronavirus “SARS-CoV-2”.
SARS, which swept the world from 2002 to 2003, has had a profound impact on the world, especially in Asia. Many people can still recall the grim situation of the epidemic, so the World Health Organization wants to avoid the inexplicable panic caused by the new virus name.
Based on current pathology sample studies and emerging basic research, including the first barbinable protein-frozen electro-mirror that was released only recently, scientists speculate that the new coronavirus should be more contagious than SARS coronavirus. In terms of fatality rates, the new coronavirus is well below SARS, which has a fatality rate of 10%. As a result, the World Health Organization is reluctant to allow the public to link the outbreak to SARS by name, and does not agree to the use of SARS-CoV-2. Currently, the World Health Organization still uses the phrase “COVID-19 virus”.
ICTV’s naming basis
However, this naming method does not apply to the International Committee on Virus Classification (ICTV) commonly used taxonomic principles, ICTV is usually responsible for giving the virus classification name, is strictly in accordance with the classification, first there is a virus species name, and then the virus name, such as the first severe acute respiratory syndrome-related coronavirus (Severe Respirator acutey syndrome-related coronavirus, a virus, and then severe acute respiratory syndrome coronavirus (severe acute respiratory syndrome coronavirus), Virus genus can not be abbreviated, but only when a single virus can be abbreviated, so there is a familiar name “SARS-CoV.”
In fact, under the severe acute respiratory syndrome-related coronavirus species, there are many coronaviruses named after SARS, either isolated from bats or from the human body.
The virus to which species, all by its genetic sequence and the similarity of the corresponding genus, that is, genetic similarity is the main reference for virus classification and naming. According to the ICTV Coronary Virus Research Group’s classification method, coronaviruses are basically classified according to the serum activity of protoproteins, as well as the relative gene sequences of some repeating proteins, which are strictly conservative in a virus species and are key to distinguishing between the genus of the virus.
By analyzing the genes and proteins of the new coronavirus, scientists determined that the new coronavirus should be attributed to the genus Severe Acute Respiratory Syndrome-coronavirus. Viruses under this species are named after SARS, so it is taxonological to refer to the new coronavirus as SARS-CoV-2.
In some previous studies, it was determined that the nucleic acid similarity of the new coronavirus and “SARS-CoV” was 79.5%, while the similarity of the new coronavirus with “SARS-CoV” was 94.6% in seven conservative non-structural protein amino acid sequences. In addition, the binding receptors of the new coronavirus on human cells are also ACE2, as are SARS-CoV. Therefore, the ICTV coronavirus research team pointed out in the paper, this shows that the new coronavirus has a genus, there is no need to give the new coronavirus extra species name, but in accordance with the SARS naming method can be operated on.
So why can MERS be named separately? This is because MERS itself cannot be classified as a severe acute respiratory syndrome-related coronavirus in an evolutionary tree, with only 54.9% genetic similarity between MERS-CoV and SARS-CoV, and the receptors that bind to human cells are not ACE2, but DDP4 (dipeptide peptide asease 4). Therefore, MERS-CoV needs to be named separately.
In fact, under the severe acute respiratory syndrome-related coronavirus species, there are many coronaviruses named after SARS, either isolated from bats or from the human body. Of these viruses, the only sars-CoV that could cause SARS was the SARS-CoV that spread from 2002 to 2003. This classification is not based on what disease the virus can cause, but is based entirely on gene sequences and conservative protein structures.
The ICTV Coronary Virus Team also explained that SARS in the names of these viruses is intended to highlight their evolutionary relationship with the original virus, not to the clinical disease level. ICTV believes that not only should new coronaviruses be named according to this method, but other types of viruses that are to be determined or that will appear in the future need to be named by classification principles, so as not to cause misunderstandings about viruses by others and scientific groups.
From the current “SARS-CoV-2” pathological data, the characteristics and transmission of the disease of the new coronary pneumonia may be different from “SARS-CoV”. The ICTV Coronary Virus Research Group believes that, in epidemiology, researchers should treat the SARS-CoV-2 outbreak differently from SARS-CoV from 2002 to 2003. Although the choice of name does not directly change the development of the disease, they also stressed that the selection of the right name can promote a unified understanding of the virus in the scientific community and promote research.
Whoever looks at SARS-CoV-2 and SARS-CoV realizes that the two viruses are genetically similar, which actually helps to study the links between the same viruses and help us better understand these human pathogens. Study the evolutionary pathways between them and coronaviruses from bats or other hosts.
Of course, when the ICTV Coronary Virus Research Group’s paper appeared on the preprinted website, many Chinese scientists had published articles in The Lancet, raising objections. In their view, such naming would have unpredictable consequences directly. Because the outbreak is not over, the virus is still evolving, whether it will become a low fatality rate in the future, the annual epidemic of seasonal virus is not clear. Calling it SARS-CoV-2 now will have serious social and economic implications for countries with future seasonal outbreaks.
In addition, ICTV is only involved in the creation and naming of virus species (virus taxa), such as species, genus, sections, etc., and not in the naming of virus specific names. In other words, the name and location of SARS-CoV-2 in taxonomy has been determined, but it is uncertain whether the scientific community will adopt the name to call the new coronavirus. What is the final generic name for the new coronavirus may only be determined by the evolution of the virus and the development of the outbreak.