"Compared to the French general population, the Covid-19 population exhibited a significantly weaker current daily smoker rate by 80.3 % for outpatients and by

"Compared to the French general population, the Covid-19 population exhibited a significantly weaker current daily smoker rate by 80.3 % for outpatients and by 75.4 % for inpatients. Thus, current smoking status appears to be a protective factor against the infection by SARS-CoV-2. Although the chemistry of tobacco smoke is complex, these data are consistent with the hypothesis that its protective role takes place through direct action on various types of nAChRs expressed in neurons, immune cells (including macrophages), cardiac tissue, lungs, and blood vessels." Edit: here's another paper. "The current study examined for the first time the prevalence of current smoking among hospitalized patients with COVID-19 in China. An unusually low prevalence of current smoking among hospitalized COVID-19 cases in China was observed when considering the population smoking prevalence. The pooled prevalence observed in the 13 studies analyzed was approximately 1/4th the population prevalence. Consistently low prevalence of current smoking was observed in all studies." https://www.qeios.com/read/article/561 https://www.qeios.com/read/article/561