Each SARS-CoV-2 virion is approximately 50–200 nanometres in diameter.

2 April 2020 source BBC / Coronavirus symptoms

More than a million cases of coronavirus have been registered globally,

according to the latest figures from Johns Hopkins University - another grim milestone as the world grapples with the spreading pandemic.

More than 51,000 people have died and more than 208,000 have recovered, according to the university's figures.