The cilia seem to grow back in about 90 days, even with vaping, which is why around the 90 day point, there's some coughing up (at least there was for me) -- it's like the last of the tar buildup is making its exit. The heat isn't so extreme, as it is with smoking, and I think it's the heat that kills the cilia.
No, its not a heat, its smoke.
Disclaimer: I Googled.
While cilia does restore rather quickly some of the damage is not reparable and reduction of some other takes rather a long time. 10 to 15 years of not smoking (after quitting) required to reduce chance of lung cancer to those of non-smoker.