E-Cigs Weaken Immune Systems in Mice, Study Says

Electronic cigarettes can weaken the immune response in mice, putting them at higher risk for infections like the flu or strep, a new study finds.

The researchers exposed mice to e-cig vapor at comparable concentrations to human users for two weeks. The researchers then exposed the mice to strep and flu, comparing their responses to mice that hadn’t been exposed to the e-cig vapor. The results showed that the mice exposed to e-cig vapor had weakened immune defenses in their lungs and were more susceptible to the infections. The mice exposed to the flu virus were more likely to contract the illness and to die from it.

MORE: What to Know About the Science of E-cigarettes.

The study looked only at mice, not at humans, but the results underscore the need for further research into the effects of e-cigarettes on humans. “E-cig exposure as an alternative to cigarette smoking must be rigorously tested in users for their effects on immune response and susceptibility to bacterial and viral infections,” wrote the authors of the study published in the peer-reviewed journal, PLOS ONE. Lead author Thomas Sussan is a scientist at the Johns Hopkins Bloomberg School of Public Health.