Human coronaviruses are found within 2 genera: alpha coronaviruses (HCoV-NL63, HCoV-229E) and beta coronaviruses (HCoV-HKU1, HCoV-oc43, severe acute respiratory syndrome coronavirus SARS-CoV, SARS-CoV-2 and Middle East respiratory syndrome coronavirus (MERS-CoV).

Symptoms of coronaviruses include runny nose, sore throat, headache, fever and cough. Although human coronaviruses generally cause mild to moderate illnesses, some can cause lower-respiratory tract infections such as pneumonia and bronchitis. These are more common in immunosuppressed individuals, infants and the elderly population. Coronaviruses are spread from person-to-person through aerosolised droplets from coughing and sneezing , close personal contact or from direct contact with infected secretions.

The incubation period of human coronaviruses is 3 to 4 days and infection generally lasts 2-18 days. Infectivity peaks on day 10 which is also the height of disease severity.