On December 31, 2019, an outbreak of pneumonia of unknown etiology was detected in the city of Wuhan (China). A week later, a new coronavirus was isolated in these patients, initially designated as 2019-nCoV and subsequently SARS-CoV-2. This is a new virus that is much closer genetically to the coronavirus of bats than to human SARS. The new virus infects and replicates in the lung parenchyma pneumocytes and macrophages in which the ACE-2 cell receptor resides. He has now infected many more people than his predecessors (> 85,000). From the clinical point of view, those infected have an average age of 55 years; the main symptoms are fever, dry cough, lymphopenia, dyspnea, and pneumonia in its severe form. The overall lethality rate is 2-3% in China and 0.1% in cases detected outside of this country. The incubation period has been set at about 3 days (0-24 days). There are no specific antivirals or vaccines.