Does smoking & vaping protect against coronavirus? Very likely. Three studies of confirmed cases showed that ~90 pct of patients were never-smokers, while only ~10 pct were smokers & ex-smokers:
1 https://onlinelibrary.wiley.com/doi/pdf/10.1111/all.14238
2 https://www.nejm.org/doi/10.1056/NEJMoa2002032
3 https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30183-5/fulltext

And a fourth study from China: 52 severely hit covid-19 patients admitted to the Wuhan Jin Yin-tan hospital in January: 32 patients died, only 20 survived.
96% of the group were non-smokers (50) and 4% were smokers (2). Both smokers survived. #covid2020 https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30079-5/fulltext