Severe acute respiratory syndrome coronavirus 2 | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
![]() | |||||||||||
Colourised transmission electron micrograph of SARS-CoV-2 virions with visible coronae | |||||||||||
![]() | |||||||||||
Model of the external structure of the SARS-CoV-2 virion[1]
| |||||||||||
Virus classification ![]() | |||||||||||
(unranked): | Virus | ||||||||||
Realm: | Riboviria | ||||||||||
Kingdom: | Orthornavirae | ||||||||||
Phylum: | Pisuviricota | ||||||||||
Class: | Pisoniviricetes | ||||||||||
Order: | Nidovirales | ||||||||||
Family: | Coronaviridae | ||||||||||
Genus: | Betacoronavirus | ||||||||||
Subgenus: | Sarbecovirus | ||||||||||
Species: | |||||||||||
Virus: | Severe acute respiratory syndrome coronavirus 2
| ||||||||||
Notable variants | |||||||||||
Synonyms | |||||||||||
|
Part of a series on the |
COVID-19 pandemic |
---|
![]() |
|
![]() |
Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2)[2] is a strain of coronavirus that causes COVID-19, the respiratory illness responsible for the COVID-19 pandemic.[3] The virus previously had the provisional name 2019 novel coronavirus (2019-nCoV),[4][5][6][7] and has also been called human coronavirus 2019 (HCoV-19 or hCoV-19).[8][9][10][11] First identified in the city of Wuhan, Hubei, China, the World Health Organization designated the outbreak a public health emergency of international concern from January 30, 2020, to May 5, 2023.[12][13][14] SARS‑CoV‑2 is a positive-sense single-stranded RNA virus[15] that is contagious in humans.[16]
SARS‑CoV‑2 is a strain of the species Betacoronavirus pandemicum (SARSr-CoV), as is SARS-CoV-1, the virus that caused the 2002–2004 SARS outbreak.[2][17] There are animal-borne coronavirus strains more closely related to SARS-CoV-2, the most closely known relative being the BANAL-52 bat coronavirus. SARS-CoV-2 is of zoonotic origin; its close genetic similarity to bat coronaviruses suggests it emerged from such a bat-borne virus.[18] Research is ongoing as to whether SARS‑CoV‑2 came directly from bats or indirectly through any intermediate hosts.[19] The virus shows little genetic diversity, indicating that the spillover event introducing SARS‑CoV‑2 to humans is likely to have occurred in late 2019.[20]
Epidemiological studies estimate that in the period between December 2019 and September 2020 each infection resulted in an average of 2.4–3.4 new infections when no members of the community were immune and no preventive measures were taken.[21] However, some subsequent variants have become more infectious.[22] The virus is airborne and primarily spreads between people through close contact and via aerosols and respiratory droplets that are exhaled when talking, breathing, or otherwise exhaling, as well as those produced from coughs and sneezes.[23][24] It enters human cells by binding to angiotensin-converting enzyme 2 (ACE2), a membrane protein that regulates the renin–angiotensin system.[25][26]
NYT-20210226
was invoked but never defined (see the help page).CDC-nCoV
was invoked but never defined (see the help page).NYT6
was invoked but never defined (see the help page).Zoonotic
was invoked but never defined (see the help page).Proximal
was invoked but never defined (see the help page).NEJM-Stability
was invoked but never defined (see the help page).WHO-PHEIC
was invoked but never defined (see the help page).WHOPandemic
was invoked but never defined (see the help page).Machhi2020Sep
was invoked but never defined (see the help page).Chan24Jan2020
was invoked but never defined (see the help page).nihSARSr-CoV
was invoked but never defined (see the help page).biol
was invoked but never defined (see the help page).WHO-SR22
was invoked but never defined (see the help page).early
was invoked but never defined (see the help page).HoffmanCell
was invoked but never defined (see the help page).