E-cigarettes do not boost pneumonia risk, study finds

    4 December 2019

    Exposure to e-cigarette vapour has no impact on the ability of Streptococcus pneumoniae to infect mouse models, according to new research published in the journal Applied and Environmental Microbiology.

    Exposure to smoke from conventional cigarettes is a critical risk factor for pneumonia. S. pneumonia is the most frequent cause of pneumonia in children five years and under, as well as adults older than 65, and immune-compromised individuals.

    In the study, the investigators compared the effects on S. pneumoniae of exposure to strawberry-flavoured e-cigarette vapour containing nicotine, the same vapour with no nicotine, cigarette smoke, and with no cigarette-related exposure.

    As compared to controls, nicotine containing e-cigarette vapour induced major changes in gene expression of pneumococcus, affecting 264 genes, mostly involved in metabolism and stress response. Nicotine free e-cigarette vapour changed altered expression of just 14 genes, and only modestly.

    “Interestingly, neither nicotine containing nor nicotine free e-cigarette vapor altered the ability of pneumococci to cause lung infection in a mouse model of infection,” said the study’s corresponding author, Dr. Kulkarni. However, both nicotine-containing e-cigarette vapor and cigarette smoke caused moderate induction of biofilm formation,” according to the report.

    “Our work is part of a long series of observations coming from a number of research labs trying to define what effects e-cigarette vapor exposure may have on human health, and to differentiate between the effects of flavoring chemicals and nicotine.”