Nicotine binds to the ACE2 receptors thus preventing the spike protein (and other bad things) from binding and making people sick. If Nicotine is proven to prevent coronavirus infections (it does) the vaccine companies would loose Emergence Use Authorization [EUA], this is why the studies showing Nicotine prevent infection have been hidden, vilified or prevented. (The nicotine can come from a patch, gum, chewing tobacco, vape juice and cigarettes/cigars. I think smoking it works best to prevent covid infections but they shut down the studies in 2021 so I don't have the data to show this)

https://greatawakening.win/p/15IrUEYOdE/x/c/4Ob9G5XWH46

Of course, forum posts here are not "authoritative" sources.