Does nicotine protect users from contracting the coronavirus SARS-CoV-2, or reduce its impact once it’s in the body? These are serious questions—and highly controversial ones—and we may have solid answers soon.
A clinical trial is set to begin in France, providing nicotine patches to hospital staff and COVID-19 patients and measuring the results. The trial has the backing of celebrated Pasteur Institute neurobiologist Jean-Pierre Changeux, an expert on the cholinergic system (which includes the nicotinic receptors).
Because most COVID-19 patient data has measured the number of infected smokers, but has not identified smokeless tobacco or e-cigarette users, it’s possible that some other component in tobacco smoke is exerting a protective effect. But the interaction between nicotine and the receptors used for access to the organs by the coronavirus is the only hypothesis that has so far been advanced by researchers, and it seems the most probable.
Scientists have speculated about the potential protective effects of nicotine since the earliest coronavirus data from China showed that smokers were infected at far lower rates than the general public. We noted in a March 12 story that five studies from China showed that just 3.9-14.5 percent of diagnosed COVID-19 patients were listed as smokers, while the smoking rate for Chinese men is about 50 percent. That gulf has been seen again and again as data came in from other cohorts.
In late January, New Zealand pharmaceutical researcher and harm reduction advocate Eliana Golberstein Rubashkyn posed a possible mechanism by which nicotine could prevent the coronavirus from adhering to the receptors in the body’s cells that are its prime entry point. She posted her suggestion on Twitter.
In late March, cardiologist and e-cigarette researcher Konstantinos Farsalinos published a preliminary study that noted the low number of smokers in published data, and proposed a similar explanation. Nicotine might block the coronavirus from finding its target cells, Farsalinos said.
Since then, data from other countries—including the United States and France—have shown similar low rates of infection among smokers, and Farsalinos has updated his study with the new information. His hypothesis has evolved to also suggest that nicotine might modulate the “hyperinflammatory” reaction of the immune system (the so-called cytokine storm) that has been noted in some of the worst COVID-19 cases. If that’s correct, nicotine might help prevent infection, and also reduce the damage caused in already infected patients.
Farsalinos calls for clinical trials with nicotine replacement therapies to test his hypothesis. The final journal publication of his paper—co-written with his University of West Attica (Greece) colleague Prof. Anastasia Barbouni and New York University Prof. Raymond Niaura—is due soon.