https://www.medrxiv.org/content/10.1101/2020.06.01.20118877v2
"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."
Suggested mechanisms that may confer a protective effect of smoking include altered host cell expression of angiotensin-converting enzyme 2 (ACE2, the receptor the virus uses to infects cells); the anti-inflammatory activity of nicotine; the antiviral effect of nitric oxide; the effects of smoking on the immune system and vapor heat-related stimulation of immunity in the respiratory tract.
Edited by TigerMatt at 12:57:05 on 08/12/20