Smoking or vaping could make you more vulnerable to a severe infection with the novel coronavirus.

Although there have not been many studies investigating this link specifically, a wealth of evidence suggests that smoking suppresses immune function in the lungs and triggers inflammation. There have been far fewer investigations of vaping, but preliminary research suggests it may do similar damage. And both long-term smokers and e-cigarette users are at a heightened risk of developing chronic lung conditions, which have been associated with more severe cases of COVID-19, as the disease caused by the new virus is called. Scientists say it therefore seems reasonable to assume that smoking—and possibly vaping—could increase the risk of developing a serious infection from the coronavirus.

Smoking is a known risk factor “A history of smoking may increase the risk of hospitalization in smokers and ex-smokers. Preventing smoking could reduce hospitalizations due to influenza. Smokers and ex-smokers should be informed of the risk of hospitalization due to influenza infection, and encouraged to stop smoking. Smokers should be considered an at-risk group to be aggressively targeted for routine influenza vaccination”. for influenza, “People who smoke are immunosuppressed to some degree. They make more mucus. It doesn’t clear the lungs as well. There are pro-inflammatory changes; immune cells are changed as well. And all that leads up to, basically, they’re more likely to get viruses and have a worse outcome.” [1]

Preliminary data from the Centers for Disease Control showed a larger number of young people coming down with COVID-19 than first expected, with patients under the age of 45 comprising more than a third of all cases, and one in five of those patients requiring hospitalization. That also tends to be the group most likely to use e-cigarettes.

We know that e-cigarettes include chemicals such as propylene glycol, glycerol, and flavorings, and that these chemicals have the ability to go deep into your lungs and cause damage. When people become critically ill from COVID-19, this also involves the deep pockets of their lungs. It's really scary to watch what could be happening in those that have both of these going on together.

Vapers’ risk of viral infections has not been studied much, although there are some epidemiological studies suggesting they are more likely to get respiratory infections,. And animal studies provide some clues. Mice that were exposed to E-cig vapor showed significantly impaired pulmonary bacterial clearance, compared to air-exposed mice, following an intranasal infection with Streptococcus pneumonia. This defective bacterial clearance was partially due to reduced phagocytosis by alveolar macrophages from E-cig exposed mice. In response to Influenza A virus infection, “E-cig exposed mice displayed increased lung viral titers and enhanced virus-induced illness and mortality”. And vaping may interfere with neutrophil function, some studies suggest[2].

Scientists at Chapel Hill have shown that e-cigarette use suppresses the activity of immune- and inflammatory-response genes in nasal cells—more so even than smoking.[3] And a preprint study found that the gene that encodes the receptor ACE2, which the novel coronavirus uses to infect cells, is more active in smokers than nonsmokers.[4]

Of course, none of these studies directly show that smoking or vaping increases the severity of COVID-19 infections; it is not clear to what extent they can be extrapolated to the current pandemic. But given that smoking and vaping do well-established harm to the immune system, it seems prudent to assume they might make coronavirus infections worse.

“For sure that a sensible thing to do for people is to stop smoking and stop vaping—and avoid secondhand exposure”.

[1] Robert Tarran, a professor of cell biology and physiology at Chapel Hill.

[2] Pub Med https://www.ncbi.nlm.nih.gov/pubmed/28495856?dopt=Abstract

[3] Pub Medhttps://www.ncbi.nlm.nih.gov/pubmed/27288488?dopt=Abstract

[4] https://www.preprints.org/manuscript/202002.0051/v1