COVID-19 pandemic

=== Cause ===
{{Main|Severe acute respiratory syndrome coronavirus 2}}
[[File:Coronavirus virion structure.svg|thumb|right|Illustration of SARS-CoV-2 [[virion]]]]
SARS‑CoV‑2 belongs to the broad family of viruses known as [[coronavirus]]es.<ref name="Fox2020">{{#invoke:cite journal ||vauthors=Fox D |title=What you need to know about the novel coronavirus |journal=Nature |date=January 2020 |pmid=33483684 |doi=10.1038/d41586-020-00209-y|s2cid=213064026 }}</ref> It is a [[Positive-sense single-stranded RNA virus|positive-sense single-stranded RNA]] (+ssRNA) virus, with a single linear RNA segment. Coronaviruses infect humans, other mammals, including livestock and companion animals, and avian species.<ref name="V'kovskik:21">{{#invoke:cite journal ||vauthors=V'kovski P, Kratzel A, Steiner S, Stalder H, Thiel V |title=Coronavirus biology and replication: implications for SARS-CoV-2 |journal=Nature Reviews. Microbiology |volume=19 |issue=3 |pages=155–170 |date=March 2021 |pmid=33116300 |pmc=7592455 |doi=10.1038/s41579-020-00468-6}}</ref>

Human coronaviruses are capable of causing illnesses ranging from the [[common cold]] to more severe diseases such as [[Middle East respiratory syndrome]] (MERS, fatality rate ≈34%). SARS-CoV-2 is the seventh known coronavirus to infect people, after [[Human coronavirus 229E|229E]], [[Human coronavirus NL63|NL63]], [[Human coronavirus OC43|OC43]], [[Human coronavirus HKU1|HKU1]], [[Middle East respiratory syndrome-related coronavirus|MERS-CoV]], and the original [[Severe acute respiratory syndrome coronavirus|SARS-CoV]].<ref name="NEJM-Novel">{{#invoke:cite journal ||vauthors=Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, Zhao X, Huang B, Shi W, Lu R, Niu P, Zhan F, Ma X, Wang D, Xu W, Wu G, Gao GF, Tan W |title=A Novel Coronavirus from Patients with Pneumonia in China, 2019 |journal=The New England Journal of Medicine |volume=382 |issue=8 |pages=727–733 |date=February 2020 |pmid=31978945 |pmc=7092803 |doi=10.1056/NEJMoa2001017}}</ref>