You will probably be hearing from medical doctors and others who are better positioned to answer that question. What I can tell you is that the scientific consensus is that it causes less population-level harm than tobacco and alcohol, but that should not be confused with its being harmless. Tobacco causes a range of harms to unborn children and, of course, there's impaired driving. There is a strong association with mental health among those who are susceptible, and exacerbating some of those problems. An estimate of the consequences in Canada says that about half of the deaths come from impaired driving, and about half come from respiratory issues related to smoking, and that's unique to the mode of administration.
That's a quick snapshot. I don't pretend to be a medical doctor, but I think that's a fair summary of the most recent evidence.