From mid-December 2019, the Wuhan Municipal Health and Health Committee (where the outbreak happened) reported a total of 59 patients with an unexplained diagnosis of viral pneumonia in Wuhan, China. On the 8th January it was officially identified as a new type of Coronavirus. Coronaviruses are a family of viruses that infect a wide range of different species including humans. Until this new coronavirus was identified, there were six different coronaviruses known to infect humans (among them the SARS and the MERS that resulted in more severe diseases).
To date, the Chinese health officials reported 26 deaths from and 830 cases of the coronavirus: it passes from person to person but more evidence are needed to determine if it spreads through the air as did SARS, or through close human to human contact as does the MERS.
The Chinese authorities rapidly communicated about the new virus and took actions in an effort to contain it. A travel lockdown that includes 12 cities near the centre of the outbreak has been established, which concerns 35 million residents.
On the 23rd of January 2020 the Coalition for Epidemic Preparedness Innovations has announced the initiation of three programmes to develop vaccines against nCoV-2019. The programme will be developed thanks to the collaboration of existing and new partnerships (with Inovio, The University of Queensland, Moderna and the U.S. National Institute of Allergy and Infectious Diseases). The aim is to advance nCoV-2019 vaccine candidates into clinical testing as quickly as possible, with the hope to bring a new pathogen from gene sequence to clinical testing in 16 weeks.
https://cepi.net/news_cepi/pneumonia-cases-of-unknown-cause-in-wuhan-china/
https://www.sciencemediacentre.org/expert-reaction-to-wuhan-coronavirus-outbreak/
http://virological.org/t/preliminary-phylogenetic-analysis-of-11-ncov2019-genomes-2020-01-19/329