The results come after researchers from a Paris hospital examined 343 patients with coronavirus as well as 139 people infected with the disease with milder symptoms.
They found that a small number of them smoked, compared to a smoking rate of around 35% in the general French population.
“Among these patients, only five percent were smokers,” said study co-author and professor of internal medicine Zahir Amoura.
The research echoes similar results published in the New England Journal of Medicine last month, which suggested that 12.6% of the 1,000 people infected in China were smokers. This figure was well below the number of regular smokers in the general population of China, about 26%, according to the World Health Organization (WHO).
The theory is that nicotine could adhere to cell receptors, blocking the virus from entering cells and spreading through the body, according to renowned neurobiologist Jean-Pierre Changeux of the Institut Pasteur in France, who is also co- author of the study.
Researchers are awaiting approval from French health authorities to continue their clinical trials.
They plan to use nicotine patches on health workers at Pitie-Salpêtrière Hospital in Paris – where initial research was done – to see if it protects them from contracting the virus.
They also asked to use the patches on hospital patients to see if it helps reduce symptoms and also on more intensive care patients, Amoura said.
Researchers are investigating whether nicotine could help prevent “cytokine storms”, an over-reaction of the immune system that scientists say could play a key role in fatal COVID-19 cases.
But with more research needed, experts aren’t encouraging people to smoke or use nicotine patches as a protective measure against the virus.
“We must not forget the harmful effects of nicotine,” said Jérôme Salomon, the top health official in France.
“Those who do not smoke should absolutely not use nicotine substitutes,” which causes side effects and addiction, he warned.
Tobacco is the number one killer in France, with around 75,000 deaths per year linked to smoking.
France is one of the countries hardest hit by the coronavirus in Europe, with more than 21,000 deaths and more than 155,000 infections reported.