N. Engl. J. Med. 382, 727–733 (2020)

Lancet 395, 497–506 (2020)

On 31 December 2019, Chinese authorities notified the World Health Organization of a series of cases of pneumonia of unknown etiology in Wuhan, the capital of Hubei province. Less than two weeks later, the putative cause of the outbreak, a novel coronavirus, was identified, and its draft genome was made public.

At this early stage in the outbreak, Zhu et al. reported that they were able to isolate the novel coronavirus from the broncheoalveolar-lavage fluid of three patients with pneumonia. They were able to propagate it in cultures of human airway epithelial cells and sequence it. Huang et al. described the clinical characteristics of 41 patients infected with the novel coronavirus. They reported fever and coughing as the most common symptoms at onset, and described pneumonia sometimes followed by acute respiratory distress in infected people. They also noted a prominent sex bias, in that 73% of patients were male, and that diabetes and hypertension were the most frequent comorbidities.