Lives saved by switching to vapes
The modellers have already had a go at it. The tool of choice is David Levy's Smoking and Vaping Model (SAVM), a cohort-based simulation now adapted to several countries. It works by comparing two futures: a ‘no-vaping’ baseline built from population, mortality and smoking-prevalence trends, against a scenario where nicotine vaping products displace cigarettes. The gap between the two gives the deaths and life-years averted.
The original US application, published in Tobacco Control in 2017, ran the numbers to the year 2100. Under the optimistic scenario, cutting smoking prevalence to 5% through vaping would prevent 6.6 million premature deaths and save 86.7 million life years.
The comparison ran from 2016 through 2100, differing on the relative harms of e-cigarettes and their effect on initiation, cessation and switching. Even the pessimistic version, which assumed heavier youth uptake of vaping and higher relative risk, still projected 1.6 million premature deaths prevented and 20.8 million life years saved.
Younger smokers gain the most, for the obvious reason that they have more years left to gain. A 15-year-old smoker in 2016 was projected to gain half a year of life expectancy on average. That's a population-wide average, so individual switchers who avoid a smoking-caused cancer or heart attack gain far more.
The same model has since been run on other countries. For Germany, it predicts 4.7 million life-years saved and 300,000 deaths avoided by 2060. A separate simulation for Russia, using a wider band of assumptions, found positive results in 88% of scenarios tested, with life-years saved ranging up to 38.5 million over 80 years.
Three things determine how good these predictions are. First is the relative risk of vaping itself. Nobody claims it's zero. The models typically assume vaping carries somewhere between 5% and 40% of the harm of smoking, and the projected benefit shrinks or grows accordingly. UK health authorities have put long-term vaping risk at under 5% of smoking's risk.
The second depends on how much switching actually happens. A model is a conditional forecast. If X% of smokers switch, then Y deaths are avoided. Whether that switching rate materializes depends on regulation, price, and how easy governments make it for smokers to reach for a vape instead of a cigarette.
Then there is youth initiation. Any net benefit gets discounted by non-smokers, especially teenagers, taking up vaping and some fraction going on to smoke. This is the most contested input in the whole exercise, and it's where optimistic and pessimistic scenarios diverge most sharply.
The answer gives not a single number, but a defensible range, wide at the edges but positive under nearly every plausible assumption. The consistent finding across US, German and Russian versions of the same model is that the range runs from several hundred thousand to several million lives saved over the coming decades, depending on how fast switching happens and how conservative we are about vaping's own risks.
Given the scale of smoking's death toll, because smoking is still remarkably good at killing people, even the pessimistic end of these projections dwarfs almost every other public health intervention on the table.
Yet the anti-nicotine lobby has it in for vapes, determined to make them more difficult to access or to use. Why? They should be encouraging them because they save lives and are projected to save millions of lives in the coming decades.
Madsen Pirie