How Scientifically Plausible Is the ‘Simian Flu’ in Planet of the Apes?

There's a lot for a single virus to do, prompting the inevitable question: How feasible is the Simian Flu from a scientific perspective?

from gizmodo http://www.gizmodo.co.uk/2017/07/how-scientifically-plausible-is-the-simian-flu-in-planet-of-the-apes/