Association Between Cigarette Smoking and COVID-19 Outcomes

17 May 2021

Alain Braillon, MD, PhD, JAMA Network:

To the Editor Lowe et al1 must be commended for being the first to my knowledge to publish a study in a core clinical journal showing evidence that tobacco smoking worsens COVID-19. This publication must end an excessively long controversy nurtured by the poor quality of epidemiological research about COVID-19 and the too-frequent lack of concern for smoking in clinical records. Indeed, the evidence is robust: confounding was taken into account and there is a dose response effect, as the Cleveland Clinic Registry records tobacco use as pack-years and not as ever/never/former.

Only South Africa and India banned the sale of tobacco products during lockdown periods against COVID-19.2 However, there and elsewhere, no government-led efforts were implemented to strengthen population-based smoking cessation support—public campaigns, quit lines, and nicotine replacement therapy availability—despite calls published online as early as April 6, 2020.3 Being among countries implementing severe lockdown, French governmental policies deserve further scrutiny. During the first lockdown the French Ministry of Health issued a legal decree (NOR: SSAZ2007919A) specifically allowing tobacco shops and e-cigarette shops to remain open during March 2020, while food retail trade on stalls and markets were forbidden the week after.

During the autumn 2020 lockdown, tobacco shops and e-cigarette shops again remained open while bookshops were closed. This policy was comprehensive: on April 23, 2020, the Ministry of Health suspended online sales of nicotine replacement therapy and restricted delivery by pharmacies to 1 month’s therapy. In addition, the European ban on menthol cigarettes, to be enforced on May 20, 2020, was postponed to July 31, 2020. Of note, in France tobacco taxes represent one-fourth of the revenue from the income tax, and daily smoking prevalence was 24% in 2019, unchanged from 2018. Furthermore, the issue also includes e-cigarettes: there has been accumulating data showing that vaping causes lung inflammation and susceptibility to viral and bacterial infections.4,5

Article Information

Corresponding Author: Alain Braillon, MD, PhD, 27 rue Voiture, 80000 Amiens, France (

Published Online: May 17, 2021. doi:10.1001/jamainternmed.2021.1920

Conflict of Interest Disclosures: Dr Braillon reported that on October 3, 2018, he resigned from the Scientific Committee of the national agency Public Health France after a written threat of being sued for libel if he did not according to the French Criminal Code Law 83-634, Article 26.

Editorial Note: This letter was shown to the corresponding author of the original article, who declined to reply on behalf of the authors.

1.Lowe  KE, Zein  J, Hatipoglu  U, Attaway  A.  Association of smoking and cumulative pack-year exposure with COVID-19 outcomes in the Cleveland Clinic COVID-19 Registry.   JAMA Intern Med. Published online January 25, 2021. doi:10.1001/jamainternmed.2020.8360
2.Egbe  CO, Ngobese  SP.  COVID-19 lockdown and the tobacco product ban in South Africa.   Tob Induc Dis. 2020;18:39. doi:10.18332/tid/120938
3.Vázquez  JC, Redolar-Ripoll  D.  COVID-19 outbreak impact in Spain: a role for tobacco smoking?   Tob Induc Dis. 2020;18:30. doi:10.18332/tid/120005
4.Wu  Q, Jiang  D, Minor  M, Chu  HW.  Electronic cigarette liquid increases inflammation and virus infection in primary human airway epithelial cells.   PLoS One. 2014;9(9):e108342. doi:10.1371/journal.pone.0108342
5.Clapp  PW, Pawlak  EA, Lackey  JT,  et al.  Flavored e-cigarette liquids and cinnamaldehyde impair respiratory innate immune cell function.   Am J Physiol Lung Cell Mol Physiol. 2017;313(2):L278-L292. doi:10.1152/ajplung.00452.2016