Not only that, they found that current combustible cigarette smokers were at a lower risk of contracting the virus. That latter finding is rather puzzling until you consider something a bit esoteric that is frequently pointed out by Dr. Dmitry Kats: some of the nicotine in tobacco, upon combustion (and also in the liver to a degree), turns into nicotinic acid, better known as Niacin (Vitamin B3) which he notes seems to really work wonders in curing and preventing COVID. To achieve this same benefit without putting one's lungs in jeopardy, it would be better to simply take niacin directly, at least 500 mg at a time, along with cofactors Vitamin C (which gets depleted by smoking), Vitamin D, zinc, quercetin, thiamine (which also gets blocked by nicotine), B-12, magnesium, selenium, melatonin, and the amino acid lysine.
So why did a previous smaller study seem to find that (younger) vapers were more likely to get COVID than non-vapers? Well, smaller sample size can magnify any biases and confounders in a study, and one obvious bias is that younger vapers often share devices, which can clearly spread the virus. They may also be more likely to attend parties that can turn into superspreader events. But the act of vaping itself, while not exactly the healthiest habit in the world, does not appear to be directly causally linked to an increased risk of contracting the disease.
Interestingly, even that previous smaller study of teens and young adults only found a correlation with "ever used" vape products, but NO correlation with recent use. That is a rather strange finding for a study that purports to show a causal link to vaping.
As for the theory that people who got that mysterious vaping illness EVALI in 2019 and early 2020 were at greater risk of COVID later on, that may very well be true. But we know now that it was primarily the result of black market THC (i.e. cannabis) vape products adulterated with questionable additives, most notably Vitamin E acetate. And it is very telling that states where cannabis was legal for recreational sale in 2019 saw not only fewer per capita cases of EVALI than states where it was not, but also fewer COVID deaths as well. Ditto for countries where cannabis was and still is fully legal (Canada, Uruguay) as well as where it is de facto legal (Netherlands) compared to their neighbors where it was not. Thus, the lingering subtle lung damage from using tainted vapes several months prior may very well increase one's susceptibility to severe and fatal COVID, meaning that the cannabis prohibitionists whose policies created these black markets may have even way more blood on their hands than we thought.
But legal and untainted vape products, whether nicotine, cannabis, or otherwise? The evidence that they significantly increase the risk of COVID simply isn't there, period. Another myth bites the dust.
