COVID-19 is an infectious disease that primarily affects the lungs. Smoking impairs lung function making it harder for the body to fight off coronaviruses and other diseases. Tobacco is also a major risk factor for noncommunicable diseases like cardiovascular disease, cancer, respiratory disease and diabetes which put people with these conditions at higher risk for developing severe illness when affected by COVID-19. WHO is constantly evaluating new research, including research that examines the link between tobacco use, nicotine use, and COVID-19. A review of studies by public health experts convened by WHO on 29 April 2020 found that smokers are more likely to develop severe disease with COVID-19, compared to non-smokers. WHO urges researchers, scientists and the media to be cautious about amplifying unproven claims that tobacco or nicotine could reduce the risk of COVID-19. There is currently insufficient information to confirm any link between tobacco or nicotine in the prevention or treatment of COVID-19.