The world just got caught completely flat footed by a virus that's closely related to the seasonal flu. I shudder to think what will happen when something 1000 times more novel and deadly inevitably comes along.
The MERS virus was much more deadly than this thing, and that wasn't very long ago. The problem with it was that it was too deadly: it killed people off pretty quickly. Pathogens that are highly deadly usually aren't very good at starting plagues, because they kill off their hosts too quickly and for that reason don't spread that much. This one is worse because it has a really long incubation period with few or no symptoms and then does its thing, but still with a relatively low mortality rate.
I guess what would really cause civilization to collapse would be a virus that has a very long incubation time with no symptoms, and then sudden very high mortality.
It's killed millions but still hasn't wiped out civilization.