How nicotine can inhibit cytokine storm in the lungs and prevent or lessen the severity of COVID-19 infection?

Statistical surveys of COVID-19 patients indicate, against all common logic, that people who smoke are less prone to the infection and/or exhibit less severe respiratory symptoms than non-smokers. This suggests that nicotine may have some preventive or modulatory effect on the inflammatory response in the lungs. Because it is known that the response to, and resolution of the SARS-CoV-2 infection depends mainly on the lung macrophages, we discuss the recent scientific findings, which may explain why and how nicotine may modulate lung macrophage response during COVID-19 infection.

Keywords: Acute respiratory distress syndrome - ARDS; COVID-19; Cytokine storm; Cytokines; Inflammation; Lungs; Macrophages; Nicotine; SARS-CoV-2; α4/α7 Nicotinic Ach receptors - nAChRs.