COVID-19 Outbreak (Update: More than 2.9M cases and 132,313 deaths in US)

Now we have a new paper that puts the RO at 4.7 - 6.6 and the number of infected doubling every 2.4 days. This just keeps getting better and better.

"Abstract
The novel coronavirus (2019-nCoV) is a recently emerged human pathogen that has spread widely since January 2020. Initially, the basic reproductive number, R0, was estimated to be 2.2 to 2.7. Here we provide a new estimate of this quantity. We collected extensive individual case reports and estimated key epidemiology parameters, including the incubation period. Integrating these estimates and high-resolution real-time human travel and infection data with mathematical models, we estimated that the number of infected individuals during early epidemic double every 2.4 days, and the R0 value is likely to be between 4.7 and 6.6. We further show that quarantine and contact tracing of symptomatic individuals alone may not be effective and early, strong control measures are needed to stop transmission of the virus."

https://www.medrxiv.org/content/10.1101/2020.02.07.20021154v1
Early, strong control measures like China welding people's doors closed.