SARS-CoV-2 and COVID-19 are confusing? What's so special about naming viruses?
The following article is from Tencent News, by Han Yue
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Author: Han Yue, Postdoctoral Fellow in Virology, University of Cambridge
Generally speaking, the naming of viruses is based on the genetic information and structure of the virus itself, in order to better facilitate the development of diagnostic methods, vaccines or drugs. Disease nomenclature, on the other hand, is intended to make it easier to discuss the prevention, transmission, severity and treatment of diseases.
Under current regulations, the International Committee on Classification of Viruses is responsible for classifying and naming a new virus, while the World Health Organization is responsible for naming the new disease caused by that virus. The current International Committee on Classification of Viruses names the new coronavirus SARS-CoV-2, and the disease it causes is named COVID-19 by the World Health Organization.
However, the International Committee for the Classification of Viruses (ICIV) issued an updated statement on March 2, stating that the naming of the new virus takes into account the genetic similarity between the new coronavirus and SARS virus and is based on phylogeny, genetic taxonomy and the existing naming system. The name SARS-CoV-2 has been determined to be the name of the new coronavirus.
Han Yue
Postdoctoral Fellow in Virology, University of Cambridge
On March 2, the International Committee on Virus Taxonomy (ICTV) Coronavirus Research Group published a new academic paper in the academic journal Nature Microbiology, addressing the controversial issue of neo-coronavirus nomenclature. The core idea of the article is that the new coronavirus is genetically similar to its SARS-CoV counterpart and is named "Severe Acute Respiratory Syndrome Coronavirus 2" (SARS-CoV-2) based on phylogeny, genetic taxonomy, and the existing nomenclature.
Wasn't the name of the new coronavirus already established? How did the "controversy" come about? This also begins with the naming history of the new coronavirus.
A. What is the name of the new coronavirus now, you can answer in a second?
From the beginning of the outbreak, I have been following the latest progress of the epidemic every day. Many different names will appear in news reports and professional literature referring to the part of the new coronavirus: Wuhan pneumonia, novel coronavirus, 2019-nCoV, Novel coronavirus pneumonia (NCP), COVID-19, and SARS-CoV-2. I believe that many people must have this confusion, how can a virus have so many names? In fact, these names include both the name of this novel virus and the name of the disease caused by the novel virus. The fact that the names of viruses and diseases are mixed together is probably the most important reason why many people are confused.
Let's take a look at the order in which these names appear: In late December 2019, the media began to report for the first time the beginning of unexplained pneumonia in Wuhan, which is generally described by the term "Wuhan pneumonia" when describing the disease. In early January, the new virus causing the disease was isolated for the first time, and it was a coronavirus that we had not found before. Since there was no suitable name for it, many reports used the abbreviation of novel coronavirus or new coronavirus to describe this newly discovered virus. During this period, SARI (Severe Acute Respiratory Infection) was also used to refer to the new coronavirus, but this was later proven to be an inaccurate description.
On January 30, 2020, the World Health Organization (WHO) suggested using 2019-nCoV to temporarily name this novel virus, with 2019 actually representing the year the virus emerged, n representing new, and CoV representing coronavirus, and the disease caused by the virus was temporarily named "2019-nCoV acute respiratory disease. "On February 8, the National Health Commission issued a notice stating that the disease was temporarily named "novel coronavirus pneumonia", or "new coronavirus pneumonia" for short. pneumonia (NCP).
On February 11, WHO announced that the new disease would be renamed COVID-19, where CO stands for coronavirus, VI stands for virus, and D stands for disease. On the same day, the International Committee on Virus Taxonomy (ICTV) proposed to name the novel virus SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus) based on biogenetic analysis, because the novel coronavirus is more closely related to SARS. Respiratory Syndrome Coronavirus 2, Severe Acute Respiratory Syndrome Coronavirus 2).
Second, how is the virus named, and what does SARS-CoV-2 have to do with SARS?
In fact, according to current regulations, a new virus and the disease it causes are usually named by different agencies: WHO is responsible for the naming of new diseases, and ICTV is responsible for the classification and naming of new viruses (species status and scientific name). Although most of the time, the disease name will be consistent with the corresponding pathogen (e.g. Dengue virus corresponding to Dengue fever Dengue, SARS coronavirus SARS-CoV corresponding to SARS). However, there are times when the names of diseases and viruses do not exactly match, such as HIV, which corresponds to AIDS (AIDS), and in this case, the new coronavirus.
For the naming of diseases, there are actually no very complicated rules, and the latest relevant WHO document was proposed in 2015 - in the guidelines for naming newly discovered infectious diseases it is mentioned that
Disease names should include generic descriptive terms in terms of disease symptoms (e.g., respiratory disease, neurological syndrome, watery diarrhea) and more specific descriptive terms in terms of robustly available information such as disease manifestations, affected populations, disease severity, or seasonal characteristics (e.g., progressive, adolescent, severe, winter). When the pathogen causing the disease is known, then that pathogen should be included in the disease name (e.g., coronavirus, influenza virus, salmonella) [2].
Also WHO advocates the use of neutral, generic terms for names instead of names of people, places, animals, foods, and occupations, due to the stigmatization and other undesirable consequences that have resulted from the names of some infectious diseases in the past.
Terms that should be avoided in disease names include geographic locations (e.g., Middle East respiratory syndrome, Spanish flu, Rift Valley fever), names of people (e.g., Crohn's Felts-Jacob disease, Chagas disease), animal or food species (swine flu, avian flu, monkey pox), references to culture, population, industry, or occupation (e.g., legion) and terms that can incite excessive panic (e.g., unknown, fatal, pandemic) [2].
However, for this time, the use of different names for new coronaviruses and diseases has been specifically explained by WHO on its own official website (see Figure 1). Generally, the naming of viruses is based more on the genetic information and structure of the virus itself, with the aim of better facilitating the development process of diagnostic methods, vaccines or drugs. Diseases, on the other hand, are named to more easily discuss issues related to disease prevention, transmission, severity, and treatment. In this outbreak, to avoid unnecessary misunderstandings in communication, WHO described the new coronavirus by the name "virus causing COVID-19 disease" or "COVID-19 virus" (see Figure 2) [3].
Back to ICTV, the reason why ICTV named the new virus as SARS-CoV-2 is also its own. This coronavirus belongs to the same genus β coronavirus of the coronaviridae family as SARS coronavirus [4].
Third, why are scientists calling for a name change? Is there any chance for the new name to be modified?
The new name SARS-CoV-2 was opposed by domestic virologists soon after its announcement. Experts, including Zhengli Shi and F. Gao, believed that the name was highly misleading to scientists without virology knowledge and the general public, and proposed to name the new virus Human coronavirus 2019 (HCoV-19) [1].
In a communication article published in The Lancet on February 19, our scientists called for not using the name SARS-CoV-2 for several reasons summarized as follows [1].
1. SARS is the name of the disease and naming the new virus SARS-CoV-2 would be seriously misleading to some scientists with insufficient knowledge of virology and to the public, who would believe that the new virus would cause SARS or similar diseases.
2. that the new virus is different from SARS-like or SARS-associated coronaviruses and that the genetic sequences of the two viruses differ.
3. the new virus differs from the SARS virus in terms of biological, epidemiological and clinical features, and the new name does not match the disease name COVID-19
4. the outbreak caused by the new virus is still developing and is far from over. The new virus may evolve into a low pathogenic, highly transmissible coronavirus that makes a comeback each winter like seasonal influenza. Given the global effects caused by the new virus, it deserves a new, independent name.
It is for these reasons that our scholars propose that the new virus should be named HCoV-19, although it is clear that ICTV has its own considerations regarding these reasons.
In the latest published paper mentioned at the beginning of this article, ICTV stated that
1. the previous system of naming viruses, especially for new viruses, often included information about the first found infected animal, location, etc., but as the new virus became better understood, for example, the discovery of a virus that could infect a new species or a new outbreak area, the old name became very confusing. the ICTV was established 50 years ago to remove this confusion, and in the existing system The naming of newly discovered viruses is based more on genetic information.
2. In the existing naming system based on genetic sequence similarity, SARS (Severe Acute Respiratory Syndrome, corresponding to the virus SARS-CoV, virus English SARS-associated coronavirus) and MERS (Middle East Respiratory Syndrome, corresponding to the virus MERS-CoV, virus English Middle East Respiratory Syndrome Coronavirus) as the first identified representative of a new species, which qualifies for the naming of a new species name, but for the new coronavirus, genetic analysis proves that it belongs to an already established virus family genus, which does not constitute a condition for naming a new species name, and it has been found to be most closely related to SARS-CoV, so it can be It is classified as this known species, and this is the main reason why the new coronavirus was named SARS-CoV-2.
3. ICTV also acknowledges that the two viruses are very different in terms of disease characteristics and modes of transmission, and in order to communicate more easily, ICTV also proposes to use the SARS-CoV-2/host/time/strain/time method to record each isolated virus strain.
So despite the controversy, I am afraid the name SARS-CoV-2 is going to be used forever.
