https://www.medrxiv.org/content/10.1101/2020.06.01.20118877v2
. RESULTS In the matched cohort, current smokers (9.8%) were significantly less prevalent among members tested positive compared to the general population, and to matched members tested negative (19.4%, P<0.001). Current smoking was associated with significantly reduced odds ratio (OR) for testing positive OR=0.457 (95% confidence interval (CI) 0.407-0.514). Among patients tested positive, there was no evidence of significantly increased risk of developing severe or fatal disease. CONCLUSION The risk of infection by COVID-19 appears to be reduced by half among current smokers. This intriguing finding may reveal unique infection mechanisms present for COVID-19 which may be targeted to combat the disease and reduce its infection rate.