No one can say for sure, of course, but it seems as if we are being urged all the time to be worried about some pandemic or other. We have a lot of resources for educating,preventing, and treating illness, so it is likely that there will not be a global pandemic.
Humans have already witnessed everything that can happen in terms of infectious diseases in the historical past. No epidemic can be worse than the Black Death, smallpox, or HIV. Although there may be major diseases in the future, they couldn't possibly be worse than what has happened in the past.