No one knows the answer to that yet, technically. I mean, we would have to have the results of a longitudinal study of never-smoker highly dedicated vapers and that just is not happening yet (or ever.)
Theoretically, vaping is a lot less damaging than smoking, but I don't know if I'd call it "good for you" in the sense that I'd prescribe to as a treatment to a small child with leukemia, at least at this point in time. I mean, thinking reasonably, inhaling what is in vape is probably not the best thing ever you could do for your health.
If you are a former smoker, and it stops you from smoking, I'd say vaping is most emphatically "good for you." But in other applications, it is somewhat murky.
Anna