A good reference reviewing the available evidence on the relation between smoking, vaping and COVID-
19 is the article written by Farsalinos, Barbouni and Nyaura [10] (see also the professional blog entry of

Farsalinos [11]). The authors conclude after reviewing the data from five studies on patients infected by
SARS-CoV-2 that the relation between smoking cigarettes and the severity of COVID-19 in infected
Chinese patients is uncertain and even protective (bearing in mind that 52.1% of Chinese men smoke
whereas only 2.7% of women do).