We congratulate Scala and colleagues on the publication of their paper on electronic cigarette (e-cigarette) use and Coronavirus Disease 2019 (COVID-19) outcomes [1]. Scala et al. focused on e-cigarette use which is increasing in many populations across the world; critically, the prevalence of dual use is also increasing and emerging as a significant public health issue. For example, in Australia, the prevalence of dual use (here defined as e-cigarettes and tobacco smoking, but not cannabis and other inhaled substances) in ≥ 14-year-olds increased from 0.9 % in 2018 to 3.7 % in 2023, with the greatest increases observed in 18–24-year-olds, from 1.2 % to 7.3 % [2].
