When someone’s lungs are exposed to flu or other infections the adverse effects of smoking or vaping are much more serious than among people who do not smoke or vape.
Smoking is associated with increased development of acute respiratory distress syndrome (ARDS) in people
When someone’s lungs are exposed to flu or other infections the adverse effects of smoking or vaping are much more serious than among people who do not smoke or vape.
Smoking is associated with increased development of acute respiratory distress syndrome (ARDS) in people with a risk factor like severe infection, non-pulmonary sepsis (blood infection), or blunt trauma. People who have any cotinine (a metabolite of nicotine) in their bodies – even at the low levels associated with secondhand smoke – have substantially increased risk of acute respiratory failure from ARDS (paper 1, paper 2, paper 3).
The recent excellent summary of the evidence on the pulmonary effects of e-cigarettes reported multiple ways that e-cigarettes impair lungs’ ability to fight off infections:
Effects on immunity
Reporting of respiratory symptoms by e-cigarette users suggests increased susceptibility to and/or delayed recovery from respiratory infections. A study of healthy non-smokers exposed to e-cigarette aerosol found decreased cough sensitivity. If human ciliary dysfunction is also negatively affected, as suggested by animal and cellular studies, the combination of reduced coughing and impaired mucociliary clearance may predispose users to increased rates of pneumonia. Exposure to e-cigarettes may also broadly suppress important capacities of the innate immune system. Nasal scrape biopsies from non-smokers, smokers, and vapers showed extensive immunosuppression at the gene level with e-cigarette use. Healthy non-smokers were exposed to e-cigarette aerosol, and bronchoalveolar lavage was obtained to study alveolar macrophages. The expression of more than genes was altered in e-cigarette users’ alveolar macrophages two hours after just puffs, including genes involved in inflammation. Neutrophil extracellular trap (NET) formation, or NETosis, is a mode of innate defense whereby neutrophils lyse DNA and release it into the extracellular environment to help to immobilize bacteria, a process that can also injure the lung. Neutrophils from chronic vapers have been found to have a greater propensity for NET formation than those from cigarette smokers or non-smokers. Given that e-cigarettes may also impair neutrophil phagocytosis, these data suggest that neutrophil function may be impaired in e-cigarette users. [emphasis added]
Studies in animals reinforce and help explain these human effects
Two weeks of exposure to e-cigarette aerosol in mice decreased survival and increased pathogen load following inoculation with either Streptococcus pneumoniae or influenza A,