Explanation:
Coronavirus has spread much more quickly than SARS or MERS.
The latest data suggests that it's less deadly than either SARS or MERS.
It will take several weeks to be confident about how the virus behaves, including its mortality rate.
International alarm over the coronavirus that emerged in Wuhan, China, in December is driven by its rapid spread and the fact that infectious disease experts cannot yet know how deadly or contagious it is.
