Large family of single stranded, positive sense RNA viruses comprising SARS and SARS-CoV-2 (COVID-19)

Comprising alpha to gamma Coronaviruses, the most notorious viruses being in order of emergence Severe Acute Respiratory Syndrome (SARS), Middle Eastern Respiratory Syndrome and SARS-CoV-2 also known as COVID-19. Genetically they are distinguished by their exceptionally large genomes for RNA viruses of around 30Kb, whereas most RNA viruses are around 10Kb