I'd heard this before, and I'm glad that this has been given further merit. I wonder if this works for other coronaviruses, like the common cold. I've long suspected that to be true, and have discussed this with other smokers who agreed with me. We never seemed to get seasonally sick like non-smokers. In fact, when I tried to quit in the past, I'd catch a cold soon after. I'm glad I quit for good, and am not condoning smoking cigarettes, but this is really fascinating stuff about niacin, nicotine, and nicotine receptors. Makes me feel less guilty about vaping, and glad I kept my supply of Nicorettes. Thanks for the info!