@Germlat,
It is a good altenative to evade the carcinogens that are on tobacco. But what Edgar said about nicotine is right. Is a highly adictive substance that has multiple side effects and in high doses can be lethal. It actually kills the smoker very slowly, how fast the poison works depends on the dosis.
I shall explain shortly. Nicotine is an stimulant that overactivates the function of all most every electrical system of our body. Including heart, vessels, vowels, brain. The neuronal receptors that can be affected by nicotine are so abundnt that the scientists that described them named precisely after the drug Nicotine receptors, although they do not need nicotine to function properly.
It can be less harmful in a way but it does not eliminates all the health risks. Nicotine alone rises blood pessure, lowers the blood flow to the cardiac muscles, increases vowel movement, lowers kidney blood flow, makes cholesterol plaques in the artery walls to be more fagile, increases bad cholesterol lowers good cholesterol.
So using vaping only takes out part of the risk, and may help some individuals quit smoking. And it makes second hand smoke also less harmfull.