Concerning tobacco use, data are lacking, and nicotine (but not tobacco) may have a protective effect. Recently, some authors postulated that the nicotinic acetylcholine receptor plays a key role in the pathophysiology of COVID-19 infection (Farsalinos et al., 2020a) and might represent a target for the prevention and control of COVID-19 infection (Changeux et al., 2020). But more evidence is required to postulate that nicotine may prevent from COVID-19 infection. Recommending its use in this indication is ahead of time, as nicotine may have deleterious effects (from the very common insomnia (up to 10%) to cardiovascular effects). To date, unpublished data on a French sample of more than 11,000 patients with COVID-19 from AP-HP (the Greater Hospital of Paris) show a low prevalence of tobacco smoking (8.5% versus around 25% in the general population). Clinical trials are required before any conclusion on a protective effect of sole nicotine (Changeux et al., 2020).
