It was previously believed that e-cigarette use often leads to respiratory illness and may also increase an individual's susceptibility to coronavirus disease 2019 (COVID-19) due to impaired lung function.

Additional contact between fingers and mouth, sharing vaping equipment, or removing face coverings while vaping while vaping can also increase the risk of COVID-19.

However, nicotine appears to reduce the risk of COVID-19 through its anti-inflammatory properties or the interaction between nicotinic acetylcholine receptors and COVID-19.

Although few studies have reported that e-cigarette use increases the severity of COVID-19, several studies have reported no association between COVID-19 and e-cigarette use in adults. Since some people vape and smoke at the same time, it is difficult to determine the independent risks of vaping.

A new Preventive Medicine Journal study uses a population-based retrospective cohort to examine polymerase chain reaction (PCR)-confirmed COVID-19 and the risk of e-cigarette use.

The current study was conducted between March 5, 2020 and November 11, 2020, with participants aged 18 to 35, with no smoking history, and with ongoing Kaiser Permanente (KPNC) health in Northern California for the previous year Program enrollment and one or more in-person inpatient or outpatient non-emergency visits between May 18, 2019 and the start of the study.

The primary outcome of this study is the diagnosis of COVID-19 by a positive PCR test. Medical assistants assessed e-cigarette use during primary care visits. Information on previous e-cigarette use was also collected.

Data were also collected on age, gender, any Medicaid enrollment in the previous year, race/ethnicity, neighborhood deprivation index (NDI), medical service area, medical comorbidities, and body mass index (BMI).

Overall, 1.2% and 1.6% of participants, respectively, reported ever or current use of e-cigarettes, while 97.2% of participants reported never using e-cigarettes. Current and former users were most commonly male, not obese and non-Hispanic white. Most current users reportedly live in neighborhoods with lower levels of poverty.

Former users tested positive for COVID-19 at higher rates than current users or users who had never used e-cigarettes.

Taken together, current research suggests that while e-cigarette use poses health risks in young people, current use is not associated with COVID-19. However, further research is needed to confirm these findings.

A limitation of the current study is that screening procedures for e-cigarette use are new and not widespread. Second, the results may not generalize.

The current study also did not assess the frequency, duration and severity of e-cigarette use. The researchers also did not include COVID-19-positive participants with mild or no symptoms.

Another limitation is that the study was conducted in the early months of the pandemic and may not be generalizable to the later stages of the pandemic. Finally, the researchers did not determine whether other factors, such as social distancing and asymptomatic detection, varied with vaping status.