I feel like vaping can actually be a lot lot worse in terms of nicotine addiction, as you're sucking on the damned thing 24/7 whereas you only smokes x amount of cigarettes per day. Tbh I think the best thing to do is just let it go completely, I know it's hard but the vape route isn't one decent human beings go down. Failing letting go, you could always keep the ciggies up, I certainly don't plan to quit smoking for a few years yet but you seem to be quite a few years older than me, in light of the fact you are currently a phD student. In all seriousness, if you are concerned about your health and want to quit then the best thing is to just give up nicotine entirely, there will come a time when you no longer miss it and are satisfied and happy in the mornings again sans cigarette. Good luck with quitting