We are past the typical peak of flu season but I will be interested to see if what we are doing now will dramatically lower flu cases as well.

If you look at what Hong Kong did with emphasizing distancing, hand washing, cleanliness, hand sanitizer, and the like, they dropped their cases of all respiratory viruses to almost nothing.

For this virus and current pandemic, you would need to look at countries that did implement strict measures either in the course of the outbreak or very early on. Also, maybe look at UK's numbers in the coming weeks. Supposedly they've been slower to implement measures than others going the opposite direction, though I believe they are beginning to change. We'll see how they're numbers continue.

Some of it may be from epidemiological modeling in terms of how things spread, but also look at history re: social distancing. I believe that there are studies with HIV saying that it may have existed before it became a pandemic for the rest of the world but HIV was more isolated to smaller villages. Same goes with Ebola.

It's also a little strange that some of our best tools for a pandemic are some of the same ones from hundreds or thousand of years ago.