Ilona Jaspers, Ph.D.
University of North Carolina at Chapel Hill
E-cigarette users have a suppressed immune response to infection by the influenza virus, according to a new NIEHS-funded study. Results have important public health implications, especially during influenza season and other respiratory-virus pandemics, like COVID-19.
The study included 49 adults aged 18 to 40 years separated into three groups: nonsmokers, smokers, and e-cigarette users. Participants were inoculated with a weakened influenza virus, which allowed the researchers to safely examine immune response to influenza infection. Before and after inoculation, the researchers collected samples of the nasal lining, which is the first line of defense against respiratory infection. They further examined antibody production, gene expression, and markers of immune response and viral load.
Viral load did not differ among the three groups. Post-inoculation, antibodies increased as expected in nonsmokers but not e-cigarette users or smokers. Compared to nonsmokers, levels of important immune proteins following inoculation were reduced in e-cigarette users, but not smokers. E-cigarette users and smokers had decreased expression of immune-related genes compared to nonsmokers, with greater gene expression changes in e-cigarette users than smokers. Sex was a significant modifier of inoculation-induced gene expression, suggesting that immune-related genes are differentially modified in male and female e-cigarette users. However, the sample size did not allow for further sex-stratified analysis.
According to the authors, results indicated that e-cigarette use suppresses immune response to respiratory viral infections and that e-cigarette use and cigarette smoking affected host immune response in different ways.
Citation: Rebuli ME, Glista-Baker E, Hoffman JR, Duffney PF, Robinette C, Speen AM, Pawlak EA, Dhingra R, Noah TL, Jaspers I. 2021. Electronic-cigarette use alters nasal mucosal immune response to live-attenuated influenza virus. A clinical trial. Am J Respir Cell Mol Biol 64(1):126–137.