Coronaviruses are a family of viruses known for containing strains that cause potentially deadly diseases in mammals and birds. In humans they're typically spread via airborne droplets of fluid produced by infected individuals.Some rare but notable strains, including Wuhan coronavirus (2019-nCoV), and those responsible for severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), can cause death in humans.

First described in detail in the 1960s, the coronavirus gets its name from a distinctive corona or 'crown' of sugary-proteins that projects from the envelope surrounding the particle. Encoding the virus's make-up is the longest genome of any RNA-based virus – a single strand of nucleic acid roughly 26,000 to 32,000 bases long. There are four known genuses in the family, named Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus. The first two only infect mammals, including bats, pigs, cats, and humans. Gammacoronavirus mostly infects birds such as poultry, while Deltacoronavirus can infect both birds and mammals.