The team’s first study looked at what happens when vaping and a coronavirus infection occur together. They exposed mice to vaped e-liquid before infecting them with a coronavirus that produces a SARS-like illness. Mice that had been ‘vaping’ before infection died at a much higher rate than those exposed to the virus alone.

When the researchers examined the lung tissue up close, they found far more severe inflammation – swollen airways, thickening of the airway walls, and a flood of immune cells crowding into spaces where they shouldn’t be. Lung weight measurements, a standard indicator of how much fluid and inflammation has built up, were also significantly higher in these mice.

Digging deeper, Onyenwoke and colleagues discovered that calcium signalling in cells appeared to be thrown off by vaping. When they gave the mice a drug to correct this, lung function improved and inflammation eased. This was an exciting finding, suggesting a possible target for future treatments.

The second study, published in 2026, zoomed in on the immune system itself. This time, the team exposed mice to vaping over four weeks using menthol-flavoured e-cigarette pods before exposing them to a substance that mimics a bacterial infection. They then carefully counted and analysed the immune cells present in the animals’ lungs.

In these mice, the numbers of ‘defender’ cells called macrophages had dropped sharply compared to mice that were only exposed to the substance mimicking infection. With fewer of these defenders on duty, the lungs were left poorly equipped to fight back.

The study also tracked specialised immune cells called myeloid-derived suppressor cells, finding that vaping disrupted their populations in complex ways. Additionally, the researchers noted notable differences between male and female mice, raising the intriguing possibility that vaping affects men and women differently.

Once again, Onyenwoke and his team found that correcting calcium signalling helped reverse some of the damage – reinforcing the idea that this pathway is central to how vaping harms the lungs.

These two studies tell a consistent and concerning story. Vaping reshapes the lungs in ways that leave them poorly prepared for infection. As the team’s research continues to show, what feels like a harmless habit may carry hidden risks.