Instigators of COVID-19 in Immune Cells are Increased in Tobacco Cigarette Smokers and Electronic Cigarette Vapers Compared to Non-smokers.

This is the first human study to report a marked increase in proteins critical for COVID-19 infection, including ACE2, TMPRSS2 and ADAM17, in immune cells from healthy tobacco cigarette smokers without lung disease compared to e-cigarette vapers and non-smokers. These findings warrant additional investigation to determine if switching to electronic cigarettes may be an effective harm reduction strategy in smokers addicted to nicotine who are unable or unwilling to quit, The increase in proteases in electronic cigarette vapers remains concerning.