A lot of the ICU cases seem to be a result of cytokine storms where the immune system goes into overdrive. Being an ex smoker appears to increase risk overall compared to both a non smoker and a current smoker. So my best guess that there is something to do with smoking that reduces the chances of a cytokine storm but if you do end up in ICU the smoking damage to lungs/heart/kidneys makes further complications likely.Apparently around 10‰ more likely to die if a smoker and you get to ICU but between two to five times less likely to be admitted to ICU in the first
At this point it's actually beyond reasonable doubt that smoking - or at the very least nicotine - is bizarrely a protective measure.
I'd like to know the crossover with vaping. If it's nicotine, then surely similar stats for people who vape would be seen.
Vaping use compared to both smokers and non smokers would be an interesting comparison, especially as vaping is more prevalent in younger age groups so some of the other risk factors that come with age less of an issue.