The recent study,” Does vaping increase the likelihood of SARS-CoV-2 infection? Paradoxically yes and no,” from the University of California, suggested that the relationship between vaping and the SARS-CoV-2 infection, is a complex one, highly dependent on the ingredients that each specific e-liquid contains.
The researchers utilized airway stem cells from human donors to create a 3D tissue model of human bronchial epithelium, which was then exposed to aerosols from JUUL and BLU vapes, to observe the impact on SARS-CoV-2 infection. The results indicated an increase in the amount of ACE2, a host cell receptor for the SARS-CoV-2 virus, in all tissues exposed to the aerosols. Additionally, the enzyme TMPRSS2, essential for the virus to infect cells, exhibited increased activity in tissues exposed to nicotine-containing aerosols. However, some of the chemicals seemed to work against each other.
The research revealed that propylene glycol and vegetable glycerin, either alone or with nicotine, can enhance COVID-19 infection through various mechanisms. But, the addition of benzoic acid to e-liquids, which has an acidic pH, was found to prevent the infection caused by propylene glycol, vegetable glycerin, and nicotine.
Other studies claim that nicotine protects against COVID-19….
Yet, while the current study suggests that nicotine can promote the infection, multiple previous studies had indicated that the compound actually has a protective effect against contracting COVID.
A 2022 study published in Preventive Medicine, “Electronic cigarette use and risk of COVID-19 among young adults without a history of cigarette smoking,” included participants aged between 18 and 35 years of age, who had no history of smoking. The compiled responses indicated that the COVID-19 test positivity rate was significantly higher in former vapers than in current users.
“Current (versus never) e-cigarette use was associated with a lower incidence of COVID-19 (33.43/1000 person-years; Table 2). There were no differences in infection comparing current to never e-cigarette use in unadjusted (hazard ratio [HR] = 0.90; 95%CI:0.63–1.30), fully-adjusted (aHR = 1.12; 95%CI:0.77–1.62) or extended models (aHR = 1.11; 95%CI:0.77–1.61),” read the results section.
….even via smoking?
To the surprise of many, the protective effect or nicotine seemed to apply even in the case of smoking. The study titled, “Association between smoking, e-cigarette use and severe COVID-19: a cohort study,” found that when compared to never smokers, current smokers were found to be at lower risk of all three outcomes, and therefore at a reduced risk of severe COVID-19 symptoms. In this study, patterns were also observed between vapers and non vapers, however the differences were less pronounced than those between smokers and non smokers.
In line with this, data from the Centers for Disease Control and Prevention (CDC) have shown that smokers represented just 1.3% of COVID-19 cases analyzed, while America’s adult smoking rate is at 13.7%. Similarly, a review of Chinese data published in the European Journal of Internal Medicine had reported that “active smoking does not apparently seem to be significantly associated with enhanced risk of progressing towards severe disease in COVID-19.”
On the otherhand, a 2022 Finnish study “Tobacco use and risk of COVID-19 infection in the Finnish general population,” analysing data from 44,199 participants across three national health surveys in Finland and aiming to determine whether nicotine users have a lower risk of COVID-19 infection than never users, reported that this was not the case.
The research team explored several forms of tobacco use: smoking, snus, vaping with and without nicotine and nicotine replacement therapy products. The compiled data did not find any evidence suggesting that nicotine acts as a protective against contacting covid.
A respiratory clinician’s expert opinion
Given these contradictory findings, Vaping Post asked award winning Dr. Ricardo Polosa for his take on the matter. He said that while data on the relationship between vaping and SARS-CoV-2 are limited and complex, there are a few hospital observational studies which have concluded that vaping is not associated with an increased risk for COVID-19. “As a clinician I favor the latter interpretation that vaping does not favour the risk of developing COVID-19.”