According to a recent French study, smokers could be better protected than others from the novel coronavirus because nicotine blocks its docking sites. Another study, however, suggests exactly the opposite.

A systematic review found that smokers have higher morbidity and mortality due to COVID-19(1). It is because smoking increases the expression of ACE-2 receptors in the lungs (2), male smokers more likely than female smokers to express.ACE-2 receptors (3).

1. Article COVID-19 and smoking: A systematic review of the evidence

2. Preprint Susceptibility Analysis of COVID-19 in Smokers Based on ACE2

3. Article Sex difference and smoking predisposition in patients with COVID-19

Hi

Smokers are likely to be more vulnerable to COVID-19 as the act of smoking means that fingers (and possibly contaminated cigarettes) are in contact with lips which increases the possibility of transmission of virus from hand to mouth. Smokers may also already have lung disease or reduced lung capacity which would greatly increase risk of serious illness. Smoking products such as water pipes often involve the sharing of mouth pieces and hoses, which could facilitate the transmission of COVID-19 in communal and social settings.

Regards

Please take a look at this useful RG link.

Article Smoking Upregulates Angiotensin-Converting Enzyme-2 Receptor...

You can notice this link, which gives a good explanation for your question, and it is titled: Does nicotine protect us against coronavirus?

https://theconversation.com/does-nicotine-protect-us-against-coronavirus-137488

Abdul Hadi Al-Qahtani

In order to answer to the question, I would like to bring to your attention our working hypothesis: Nicotinic Cholinergic System and COVID-19. In brief, Spike has obtained a toxin-like sequence which seems to interact with the, neighboring to ACE2, alpha7 nAChRs and by this way is causing hyper-inflammation, angiitis, anosmia etc.

Please have a look at the following:

1. Farsalinos K, Niaura R, Le Houezec J, Barbouni A, Tsatsakis A, Kouretas D, Vantarakis A, Poulas K. Nicotine and SARS-CoV-2: COVID-19 may be a disease of the nicotinic cholinergic system. Toxicol Rep. 2020 Apr 30. doi: 10.1016/j.toxrep.2020.04.012. 

2. Farsalinos K, Angelopoulou A, Alexandris N, Poulas K. COVID-19 and the nicotinic cholinergic system. Eur Respir J 2020. doi. 1183/13993003.01589-2020

3. Farsalinos K, Eliopoulos E, Leonidas D, Papadopoulos G, Tzartos S, Poulas K. Molecular Modelling and Docking Experiments Examining the Interaction between SARS-CoV-2 Spike Glycoprotein and Neuronal Nicotinic Acetylcholine Receptors. Preprints 2020;2020050365. doi: 20944/preprints202005.0365.v1.

4. Farsalinos K, Eliopoulos E, Tzartos S, Poulas K. Nicotinic Cholinergic System and COVID-19: Identification of a Potentially Crucial Snake Toxin-Like Sequence in the SARS-CoV-2 Spike Glycoprotein. Preprints 2020, 2020050301 (doi: 10.20944/preprints202005.0301.v1). Version 1 : Received: 17 May 2020 / Approved: 18 May 2020 / Online: 18 May 2020 (11:51:44 CEST)

Please also see the following RG links.

Preprint Cigarette smoke triggers the expansion of a subpopulation of...

Preprint Current tobacco smoking and risk from COVID-19: results from...

Article ACE-2 expression in the small airway epithelia of smokers an...

Article Tobacco Smoking a Potential Risk Factor in Transmission of C...

Please check a recent pre-publication:

https://www.medrxiv.org/content/10.1101/2020.06.01.20118877v1?fbclid=IwAR0SEHUBrx_bCRx0V1VJxYd-04GDrz6woBgoulgzFd-gxoBtctEY8l3y9iA

CONCLUSION The risk of infection by COVID-19 appears to be reduced by half among current smokers. This intriguing finding may reveal unique infection mechanisms present for COVID-19 which may be targeted to combat the disease and reduce its infection rate.

Please, take into consideration that the beneficial effect CAN NOT ORIGINATE from SMOKE but from NICOTINE.

NO, A LOT OF STUDIES FOUND THAT DECREASE INCIDENCE OF COVID-19 AMONG SMOKERS BUT IF THEY ALREADY INFECTED THEY BECOME WORSE.

In the conversation around COVID-19, we have been hearing a lot about receptors. These are structures composed of protein, and they receive signals that may be integrated into the body. These signals can come from various substances, such as a hormone, a drug, or an antigen. For example, the surface of the human cell has receptors called ACE2, which open the door for the novel coronavirus SARS-CoV2 to enter the body. At the center of the nicotine, the hypothesis is a receptor that responds to nicotine as well as a chemical called acetylcholine. Hence its name: “nicotinic acetylcholine receptor”, abbreviated as nAChR. It is found in parts of the nervous system, muscle, and certain tissues of organisms including humans. Since nicotine is known to bind with the nAChR receptor, the second part of the hypothesis goes like this: If nicotine is present on the receptor, and the novel coronavirus arrives, then the nicotine would block the interaction.

https://indianexpress.com/article/explained/does-nicotine-help-fight-covid-19-the-science-behind-a-novel-hypothesis-6394013/

Please see the following links:

https://www.qeios.com/read/WPP19W.3

https://www.humanbrainproject.eu/en/follow-hbp/news/could-nicotine-help-against-covid-19/

Smokers are more vulnerable to COVID but indirectly.

Dear Manal,

Please check the following publications. Will offer more info to the issue:

Konstantinos Farsalinos, Athina Angelopoulou, Nikos Alexandris, Konstantinos Poulas, COVID-19 and the nicotinic cholinergic system. European Respiratory Journal 2020; DOI:10.1183/13993003.01589-2020, https://erj.ersjournals.com/content/early/2020/05/19/13993003.01589-2020

Konstantinos Farsalinos, Raymond Niaura, Jacques Le Houezec, Anastasia Barbouni, Aristidis Tsatsakis, Dimitrios Kouretas, Apostolos Vantarakis, Konstantinos Poulas, Editorial: Nicotine and SARS-CoV-2: COVID-19 may be a disease of the nicotinic cholinergic system, Toxicol Rep. 2020, Apr 30. DOI: 10.1016/j.toxrep.2020.04.012

Article Editorial: Nicotine and SARS-CoV-2: COVID-19 may be a diseas...

Molecular Modelling and Docking Experiments Examining the Interaction between SARS-CoV-2 Spike Glycoprotein and Neuronal Nicotinic Acetylcholine Receptors Preprint from Preprints.org, 23 May 2020 DOI: 10.20944/preprints202005.0365.v1 PPR: PPR166903 (Accepted for publication in Int. J. Mol. Sciences - More extended version)

Nicotine increases the risk of lung cancer and increases the risk of developing various diseases of the respiratory tract, reduces the overall immunity of the body. Due to the fact that over 90 percent. People dying from Covid-19 disease also have other comorbidities associated with other diseases and reduced overall immunity of the body for various reasons, so nicotine is one of the factors that lower the overall resistance of the body. Therefore, nicotine is also one of the factors that increase the risk of comorbidities in the face of possible disease with Covid-19 after infection with the SARS-CoV-2 Coronavirus (Covid-19) and increases the risk of dying from Covid-19 in the event of severe Covid disease. 19.

Best regards,

Dariusz Prokopowicz

I fully agree with Dr. Dariusz Prokopowicz. Smokers are getting affected more, if virus enter inside the lungs.

It is a myth that smokers are protected against SARS-CoV-2 infection.

https://www.nature.com/articles/s41533-021-00223-1