Coronavirus: tobacco, a protection against SARS-CoV-2?

Since the start of the health crisis, figures have helped us to better fight the virus. Among these, a statistic which calls into question: the contamination rate of smokers, reduced between 1.4% and 12.5% according to several studies.

But does tobacco constitute a real protection against the virus? Analysis.

Let us answer

La théorie est soutenue par de nombreuses études à travers le monde: le tabac pourrait avoir un effet protecteur contre l’infection au coronavirus. Une théorie appuyée par une récente étude française menée sur 350 malades hospitalisés et 150 malades légers. Parmi ces patients, il y avait seulement 5% de fumeurs “explique à l’AFP le professeur de médecine interne Zahir Amoura, qui a mené cette dernière étude, soit” 80% de moins de fumeurs chez les patients Covid que dans population générale de même sexe et de même âge “

What do the studies say?

“L’hypothèse est que la nicotine en se fixant sur le récepteur cellulaire utilisé par le coronavirus l’empêche ou le retient de s’y fixer” et ainsi de pénétrer dans les cellules et de se propager dans les autorités, explique à le Pr Jean-Pierre Changeux, de l’Institut Pasteur et du Collège de France. C’est ce fameux récepteur nicotinique de l’acétylcholine qui serait à l’origine de la variété des symptômes du Covid-19, dont la perte d’odorat et des troubles neurologiques, selon les chercheurs.

L’hypothèse sera bientôt mise à l’épreuve à l’hôpital de La Pitié-Salpêtrièreoù une série de tests sont prévus. Dès le feu vert final obtenu, avec le soutien du ministre de la Santé Olivier Véran, des patchs nicotiniques vont être administrés à des dosages différents dans trois essais: en préventif à des soignants, pour voir si cela les protège; en thérapeutique à des patients hospitalisés en médecine, pour tenter de diminuer leurs symptômes; et enfin à des patients graves en réanimation, détaille le Pr Amoura.

Le corps médical appelle cependant la population à ne pas se jeter sur les stocks de cigarette. Comme établi depuis longtemps, la consommation de tabac est responsable de la dégradation du système respiratoire et de nombreux cancers, ainsi que de la mort d’une personne toutes les 6 secondes.

Strangely, the proportion of smokers among those hospitalized for coronavirus is quite low, which suggests a protective role for nicotine.

How would nicotine block the virus in the brain?

Does Nicotine Protect From Coronavirus? This hypothesis could still seem preposterous a few days ago but it is being analyzed seriously within the hospital of La Pitié-Salpêtrière in Paris.

Fewer smokers among Covid-19 patients

Data from several countries report a low proportion of smokers among patients infected with Covid-19. In China, two studies published in February in The Lancet and the New England Journal of Medicine show that this population is less infected with the coronavirus. In France, the AP-HP (Public Assistance-Hospitals of Paris) puts forward a rate of 8.5% of smokers out of 11,000 Covid-19 patients admitted to hospital in early April, while there are 25.4 % of smokers in the general population.

“Daily smokers have a much lower probability of developing a symptomatic or serious SARS-CoV-2 infection compared to the general population”

Professor Zahir Amoura
department of the Pitié-Salpêtrière hospital

A study published on April 21, 2020. Carried out with 343 patients (median age of 65 years), hospitalized for a Covid-19 infection (excluding intensive care units) and 139 patients (median age of 44 years) , followed on an outpatient basis also contaminated but with milder symptoms, this research confirms that only 4.4% were daily smokers among the first and 5.3% among the second, ie “80% fewer smokers in Covid patients than in the general population of the same sex and the same age “notes the doctor.

How could nicotine protect from Covid-19?

Nicotine would prevent the binding of the coronavirus to receptors in the brain.

According to Professor Amoura, “nicotine and the nicotinic receptor, not cigarette smoke per se, which is responsible for a very heavy public health burden with more than 78,000 deaths per year in France, can be involved in the pathway leading to viral infection, especially in the more severe forms of Covid-19 “. In fact, nicotine binds to nicotinic receptors present in the brain called “nicotinic acetylcholine receptor”. It would then prevent the attachment of the SARS-CoV-2 coronavirus to these receptors and limit its progression in the body, as well as the worsening of symptoms.

We know that “SARS-CoV-2 could spread from the olfactory mucosa, then from the neurons of the brainstem, going in some cases to the respiratory centers. It enters the motor neurons and then spreads to central nervous system where it creates serious behavioral disorders “recall the Academy of Sciences, the Assistance Publique-Hôpitaux de Paris and Sorbonne University in a press release.

Nicotine would reduce the hyper-inflammation present in severe cases of Covid-19. To validate all these hypotheses, nicotine patches will be administered at different dosages in three trials, at La Pitié-Salpêtrière hospital in Paris.

Tobacco is responsible for the deaths of 8 million people a year worldwide

Meanwhile, no question of rushing on cigarettes or nicotine patches (or other nicotine substitutes), warns the Alliance against tobacco in a press release of April 17. And for users of smokeless nicotine (exclusive vapers and people in withdrawal), they do not “expect to be more protected than the rest of the population against the epidemic of COVID-19”. The association recalls that “tobacco is responsible for a pandemic resulting in the premature death of 8 million people per year worldwide” (more than 70,000 in France) and that “if a protective effect of nicotine against -vis COVID-19 remains to be proven, the benefit / risk ratio argues largely in favor of smoking cessation “.

The Minister of Health Olivier Véran also called for caution Wednesday April 22 during questions to the government in the Senate, recalling that “tobacco does not protect but kills” and that nicotine “is certainly not a self-medication treatment “. It is an “interesting track” but “attention” he hammered: “Someone who is not a smoker and who puts a nicotine patch will feel it pass: vomiting, dizziness, malaise.”