Coronavirus Disease 2019 (COVID-19) and Smoking


Relationship Between Smoking/Vaping and COVID-19

People who are immunocompromised have increased susceptibility to COVID-19. Making certain lifestyle choices such as smoking or vaping can contribute to weakened immune systems. 
As we know, smoking or vaping affects the respiratory system. Tobacco smoking is a major factor for developing lung cancer and other chronic lung disease in which pulmonary cells get inflamed and damaged. Even though not much is known yet about the chronic effects of vaping, preliminary data shows that it possibly causes chemical irritation or allergic and immune reactions.
Smoking may increase the risk from COVID-19 by weakening the immune system, increasing susceptibility by impairing lung function, and increasing the likelihood that the illness will progress from mild respiratory illness to the most extreme stages like acute respiratory distress (ARD) and cardiovascular complications. According to Albert Rizzo, M.D., chief medical officer of the American Lung Association, COVID-19 is an infection that attacks lung cells aggressively. Having a damaged lung on top of a virus that specifically attacks the lungs can be devastating.

Smoking and COVID Complications

Even though there are studies showing no relationship between smoking and progression of COVID-19 disease, there are other studies that show a significant relationship. A study by Guan, et al. published in The New England Journal of Medicine found that current smokers were more than twice as likely to develop severe symptoms from COVID-19 compared to non-smokers. In addition, they found that patients with compromised pulmonary status upon admission had worse outcomes. In a related study, Liu, et al. concluded that history of tobacco use is associated with 14 times the likelihood of developing COVID-19 pneumonia progression. In a meta-analysis of 12 published studies conducted by Patanavanich and Glantz involving patients in the United States, Korea and China, the authors found that smoking is significantly associated with COVID-19 progression.

How Smoking Weakens the Airways

Why does being a current smoker predispose someone to developing more severe illness after being diagnosed with COVID-19? Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative agent of COVID-19. It is believed that the angiotensin converting enzyme II (ACE-2) is the main receptor being used by SARS-CoV-2 to gain entry into a person’s airway and cause infection. In a study conducted by Leung et al., the authors found that patients who are current smokers and have a diagnosis of COPD have upregulation of ACE-2 expression in the lower airways, which may increase the likelihood of COVID-19 progression in these populations. This finding was strengthened by an analysis conducted by Wang, et al. They concluded that increased levels of ACE-2 are present inside the airways of current smokers but not among never or former smokers. This predisposes current smokers to be more susceptible to COVID-19 complications.

How Cancer Multiplies Risk

Patients with cancer may be at greater risk of being immunocompromised depending on the type of cancer they have and the type of treatment they receive. During the time of active cancer treatment, the risk of being immunocompromised is typically highest, especially during treatment with chemotherapy, radiation, surgery, targeted therapy, immunotherapy and stem cell transplant. Smoking is well documented to affect treatment efficacy, cancer susceptibility and progression. It also makes the immune system less effective at fighting off infections. Add cancer on top of smoking and you have multiplied your risk for COVID-19 infection and complications.

Effect of COVID-19 on Racial/Ethnic Minority Patients who Smoke

Health disparities are seen in cigarette smoking among ethnic minority groups. COVID-19 also affects racial and ethnic minority groups disproportionately. In some cities, black/African American and Hispanic/Latino populations have been identified as having higher death rates compared to white or Asian populations. Researchers and scientists are working to confirm these data and to determine ways to prevent and help reduce the impact of COVID-19 on the health of racial and ethnic minorities, who may be more vulnerable because of their smoking and vaping habits.

What You Can Do to Help Yourself

If you don’t use tobacco, be smart, don’t start.
Quit smoking or vaping! We need to do all we can to prevent getting this virus to begin with, but at times, that may not be possible. Thus, it is imperative to quit smoking and vaping to maintain healthier lungs to prevent the worst possible outcomes.
Reach out for help. There are many effective resources that can help you quit, such as the California Smokers Helpline at 800-NOBUTTS,, SmokefreeTxT and free quitting apps. The City of Hope Tobacco Cessation team is here to help you manage your cravings and withdrawal symptoms. We also have an engaging weekly support group, which is currently meeting online during this time of social distancing.
You can reach us at 626-256-4673, ext. 89114, or 626-218-0519, or via email at


  • Alifano M, Alifano P, Forgez P, Iannelli, A. (2020). Renin-angiotensin system at the heart of COVID-19 pandemic. Biochimie.
  • American Lung Association. (2020). What you need to know about smoking, vaping and COVID-19.
  • Bäcker A. (2020). Non-black Latinos Spend More Time Outdoors and Have Lower COVID-19 Morbidity and Case Fatality Rates Than Non-Latinos. Available at SSRN 3576374.
  • Emami A., Javanmardi F., Pirbonyeh N., Akbari A. (2020). Prevalence of underlying diseases in hospitalized patients with COVID-19: a systematic review and meta-analysis. Archives of Academic Emergency Medicine, 8(1).
  • Guan W., et al. (2020). Clinical characteristics of coronavirus disease 2019 in China. The New England Journal of Medicine. DOI:10.1056/NEJMoa2002032
  • Leung JM. (2020). ACE-2 expression in the small airway epithelia of smokers and COPD patients: Implications for COVID-19. European Respiratory Journal.
  • Levine D. (2020). Does smoking and vaping make coronavirus worse? U.S. News & World Report.
  • Lippi G, Henry BM. (2020). Active smoking is not associated with severity of coronavirus disease 2019 (COVID-19). European Journal of Internal Medicine.
  • Liu W, et al. (2020). Analysis of factors associated with disease outcomes in hospitalized patients with 2019 novel coronavirus disease. Chinese Medical Journal. DOI:10.1097/CM9.0000000000000775
  • Patanavanich R, Glantz SA. (2020). Smoking is associated with COVID-19 progression: A meta-analysis.
  • Prompetchara E, Ketloy C, Palaga T (2020). Immune responses in COVID-19 and potential vaccines: Lessons learned from SARS and MERS epidemic. Asian Pac J Allergy Immunol38(1), 1-9.
  • Qiu F, et al. Impacts of cigarette smoking on immune responsiveness: Up and down or upside down? Oncotarget 8, 268-284, DOI:10.18632/oncotarget.13613 (2017)
  • Sopori M. (2002). Effects of cigarette smoke on the immune system. Nature Reviews Immunology, 2(5), 372-377.
  • The American Cancer Society. (ACS)(2020). From
  • The Centers for Disease Control and Prevention (CDC) (2020). Coronavirus disease 2019 (COVID-19) Groups at higher risk for severe illness.
  • The Centers for Disease Control and Prevention (CDC) (2020). COVID-19 in Racial and Ethnic Minority Groups. From
  • Wang J, et al. (2020). Susceptibility analysis of COVID-19 in smokers based on ACE2. doi: 10.20944/preprints202003.0078.v1
  • Yancy CW. (2020). COVID-19 and African Americans. JAMA.