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Well, we can produce vaccines for influenza more easily than the wait we had for the coronavirus. Of course the biggest problem is that we have a substantial part of the global population being indoctrinated by nonsensical ideas that vaccines are bad - unfortunately bird flu tends to have a higher mortality rate than coronavirus too.
On the other hand, I doubt it will be societal collapse levels.
I wonder how prepared we are. Bird flu is substantially harder to contain than Coronavirus. >

The US has vaccines, but not enough to instantly vaccinate 8 billion + people. 
At the end of the day a plan is plan and that's all it is. A lot can happen that leads to better or worse outcomes than nations have planned for.
Best case: Maybe a 1918 type situation.
Worst case: Societal collapse type event.
Most likely, something in between the two.