Illustration of a SARS-CoV-2 coronavirus (previously 2019-nCoV) that was first identified in Wuhan, China, in December 2019. It is an enveloped RNA (ribonucleic acid) virus. Within the membrane are spike proteins (large), membrane proteins (light pink) and envelope proteins (lighter purple clusters). SARS-CoV-2 causes the respiratory infection Covid-19, which can lead to fatal pneumonia. As of March 2020, the virus has spread to many countries worldwide and has been declared a pandemic. Over 100,000 have been infected with several thousand deaths.