Possible resurgence of smallpox for one. Scientists have already found it in a thawed out corpse from Siberia. And no one born after 1970 has been vaccinated for it. Even so, there’s no guarantee that those with the vaccine will be protected against a resurgence of ancient viral strains.

You’re right. Coronavirus will not be our only pandemic in the next century. It won’t even be the worst. It’s a trial run (response wise). And, at least here in US, we’re failing. Miserably. As for the rest of the world, time will tell.