is a coronavirus?
Coronaviruses are a large family of viruses known to
cause diseases ranging from the common cold to more
serious diseases such as the Middle East Respiratory
Syndrome (MERS) and the Severe Acute Respiratory
They are positive-stranded RNA viruses with a
crown-like appearance under the electron microscope.
The subfamily Orthocoronavirinae of the family
Coronaviridae is further classified into four
coronavirus (CoV) genera: Alpha-, Beta-, Delta- and
Gammacoronavirus. The Betacoronavirus genus is
further divided into five subgenera (including the
Coronaviruses were identified in the mid-1960s and
are known to infect humans and a variety of animals
(including birds and mammals). Epithelial cells in
the respiratory and gastrointestinal tract are the
primary target cells.
To date, seven coronaviruses have been shown to
is a novel coronavirus?
Common human coronaviruses: HCoV-OC43 and
HCoV-HKU1 (Betacoronavirus) and HCoV-229E and
HCoV-NL63 (Alphacoronavirus); they can cause
common colds but also severe lower respiratory
other human Coronaviruses (Betacoronavirus):
SARS-CoV, MERS-CoV and 2019-nCoV (now named
A novel coronavirus (nCoV) is a new strain of
coronavirus never previously identified in humans.
In particular, the virus named SARS-CoV-2 (formerly
2019-nCoV), was never identified before it was
reported in Wuhan, China, in December 2019.
The virus that is causing the current coronavirus
outbreak has been named ‘severe acute respiratory
syndrome coronavirus 2’ (SARS-CoV-2). This
designation was communicated by the International
Committee on Taxonomy of Viruses (ICTV), virus taxa
(i.e. species, genus, family, etc.). The name was
given by a group of experts specially appointed to
study the novel coronavirus. According to this pool
of scientists, the novel coronavirus is a sister to
severe acute respiratory syndrome coronaviruses (SARS-CoVs);
this is why it has been named SARS-CoV-2.
The disease caused by the novel Coronavirus has been
named ‘COVID-19’ (where "CO" stands for corona, "VI"
for virus, "D" for disease and "19" indicates the
year in which it occurred). This was announced on 11
February 2020 by the Director-General of the WHO, Dr
Tedros Adhanom Ghebreyesus.
the new virus the same as SARS?
No. The novel Coronavirus (now named SARS-CoV-2,
formerly labelled 2019-nCoV) belongs to the same
family of viruses as the Acute Severe Respiratory
Syndrome (SARS) virus, but it is not the same virus.
The novel Coronavirus, which is responsible for the
respiratory disease now named COVID-19, is closely
related to the SARS-CoV and is genetically
classified in the genus Betacoronavirus, subgenus
did the novel coronavirus appear?
The appearance of new viruses that originally only
infected animals but then make the jump from animal
to humans is a well-known phenomenon (‘spillover’),
and this is what seems to have happened with the new
coronavirus (SARS-CoV-2). Currently, the scientific
community is trying to identify the source of the
the source of the coronavirus causing COVID-19 known?
To date, the source of SARS-CoV-2, the coronavirus
that causes COVID-19, is unknown. Available evidence
suggests that SARS-CoV-2 is of animal origin and is
not a constructed virus. Most likely the ecological
reservoir of SARS-CoV-2 resides in bats. SARS-CoV-2
belongs to a group of genetically related viruses,
including SARS-CoV (the coronavirus causing SARS)
and a number of other coronaviruses isolated from