There is plenty of research out there that shows that vaping is 95% less harmful than smoking tobacco cigarettes. The primary concern from smoking cigarettes is the inhalation of the additives in the tobacco that cause cancer. The vapor produced from the vaporizer is mostly water, so this issue is avoided. For more information, check out the Government of Canada Source.
However, do note that nicotine can cause health problems. You can opt out of buying e-liquids with nicotine to avoid these issues.
In comparison, traditional tobacco products contain at least 80 cancer causing chemicals before its combustion, and over 5,000 afterwards, including deadly tar. E-Liquid contains 3-4 food base products.
Not saying that vaping is healthy but a HEALTHIER alternative than smoking cigarettes.
You be the judge.