Just to make certain everyone knows, on 29 January of this year in The New England Journal, two articles were published:
A Novel Coronavirus from Patients, with Pneumonia in China, 2019
In December 2019, a cluster of patients with pneumonia of unknown cause was linked to a seafood wholesale market in Wuhan, China. A previously unknown betacoronavirus was discovered through the use of unbiased sequencing in samples from patients with pneumonia. Human airway epithelial cells were used to isolate a novel coronavirus, named 2019-nCoV, which formed a clade within the subgenus sarbecovirus, Orthocoronavirinae subfamily. Different from both MERS-CoV and SARS-CoV, 2019-nCoV is the seventh member of the family of coronaviruses that infect humans. Enhanced surveillance and further investigation are ongoing.
and
Early Transmission Dynamics in Wuhan, China, of Novel Coronavirus–Infected Pneumonia
On the basis of this information, there is evidence that human-to-human transmission has occurred among close contacts since the middle of December 2019. Considerable efforts to reduce transmission will be required to control outbreaks if similar dynamics apply elsewhere. Measures to prevent or reduce ransmission should be implemented in populations at risk.
Now one must wonder who dropped the ball here. Timelines often tell the entire story. Most people think we did not know until two months latter. Read the last sentence above, I had.