Terms and Definitions: SARS-CoV-2 and Covid-19


Figure 1: The image of the infamous SARS-CoV-2, taken using transmission electron microscope (TEM). (Photo: GEN) The diameter of the virus is around 120 nm (Britannica, accessed March 21, 2020). As a comparison, imagine lining these guys up in a straight line, all 1,000,000 of them, and you will get 1 mm!

SARS-CoV-2: The Virus

First and foremost, SARS-CoV-2 is the name of the virus that is behind all the public health troubles we are facing worldwide now, and stands for: severe acute respiratory syndrome coronavirus 2 (WHO, accessed March 21, 2020). SARS-CoV, however, is the name of the virus that caused the 2003 outbreak. Remember 2003? I do.

Coronavirus: The Family

So, SARS-CoV-2 belongs to a family of virus called coronavirus, which can be further categorized into four subgroups: alpha, beta, gamma and delta, based on their sequences (CDC, accessed March 21, 2020). Scientists are an imaginative lot. The term “corona-virus” was coined because apparently the virus looks like a crown under the microscope. I will leave it up to you to make your own judgement–whether it looks like a crown or not. See Figure 1 above.

Coronavirus is a large family of viruses. Many coronaviruses have been circulating among animals, causing respiratory and gastrointestinal problems in animals without infecting humans; while only four coronaviruses have been found to be able to infect humans and cause mild cold symptoms in human patients, prior to the emergence of SARS-CoV in Asia in 2003 and MERS-CoV in the Middle East in 2012. However, virologists or public health experts have been concerned about the possibilities of a the emergence of newly evolved, fatal coronavirus strains that can infect humans, which brings us to 2003, 2012 and now the 2019-2020 outbreak.

SARS-CoV-2 is a newly evolved coronavirus strain, a member of the betacoronavirus subgroup, and the seventh coronavirus (that we know of) known to infect humans. (CDC, accessed March 21, 2020)

Covid-19: The Disease

Covid-19, coronavirus (infectious) disease 2019, is name of the disease resulting from SARS-CoV-2 infection, and the official name coined by WHO (WHO, accessed March 21, 2020). The naming of this disease (or any diseases for that matter) is not trivial, and takes a few important factors into account. It has “2019” in the name to indicate the year it emerged and–more importantly–free of any region names to avoid casting a stigma on a certain population. Traditionally, disease names include the regions, when appropriate, for scientific purposes to be more readily identifiable. But, as you know, people find creative ways to spread hatred and cast stigma regardless of the officials’ efforts, with or without the region name attached. Human nature, I supposed.

From what we can gather so far, the symptoms of Covid-19 include fever, dry cough, tiredness, shortness of breath, or potentially diarrhea. Its similarity to flu symptoms, sans diarrhea, has caused much confusion among the public, as well as medical professionals. Besides the chaos and confusions, the bigger problem is actually when Covid-19 patients develop severe pneumonia and eventually face fatalities. Even though fatality happens more commonly among people who are older, in the 70-80 year-old age group or those who have underlying conditions, there are a number of severe and fatal cases reported among younger, otherwise healthy patients as well. Just saying. #stayhome

Covid-19 Among Children

From a study at Wuhan Children’s Hospital, published on March 18, 2020 in the New England Journal of Medicine (NEJM), where 1391 children were assessed and tested, those infected by SARS-CoV-2 display a spectrum of symptoms, with most having milder symptoms, like coughs, consistent with many news articles. 41.5% of the infected children have fever. On the other extreme, there are a few children with underlying conditions end up needing intensive care or leading to fatalities. Again, don’t take the chance. Do take precautions. #stayhome


Genetic Engineering & News. SARS-CoV-2 Insists on Making a Name for Itself. Accessed March 21, 2020.

Encyclopedia Britannia. Coronavirus. Accessed March 21,2020.

CDC. Human coronavirus types. Accessed March 21, 2020.

WHO. Naming the coronavirus disease (COVID-19) and the virus that causes it. Accessed March 21, 2020.

Lu, D. et al. SARS-CoV-2 Infection in Children. NEJM, March 18, 2020. DOI: 10.1056/NEJMc2005073

Saif LJ. ANIMAL CORONAVIRUSES: LESSONS FOR SARS. In: Institute of Medicine (US) Forum on Microbial Threats; Knobler S, Mahmoud A, Lemon S, et al., editors. Learning from SARS: Preparing for the Next Disease Outbreak: Workshop Summary. Washington (DC): National Academies Press (US); 2004. Available from: https://www.ncbi.nlm.nih.gov/books/NBK92442/

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