Smoking and vaping irritate the lungs and may make smokers/vapers more susceptible to COVID-19. Cigarette smoking has been shown to weaken the immunice system and compromosie the lungs. E-cigarettes may cause lung inflammation. Once infected, smokers/vapors may have a tougher time with COVID-19 than those who do not smoke or vape. This also increases the spread of the virus.
Studies also shows that mice exposed to secondhand smoke were more susceptible to viral and bacterial infections.