Frontline health workers and patients in France may be given nicotine patches after studies found that four times fewer smokers contracted Covid-19 than non-smokers.

It may sound counterintuitive that people who puff on Gauloises are less likely to catch a virus that can cause deadly attacks on the lungs. However, that was the statistical outcome of an in-depth study conducted by the Pasteur Institute, a leading French research centre into the disease.

The institute tested almost 700 teachers and pupils of a school in Crépy-en-Valois in one of the hardest-hit areas in France, as well as their families. The “highly accurate” tests found that only 7.2 per cent of smokers from among the adults tested were infected while four times as many non-smokers, some 28 per cent, were infected.

Arnaud Fontanet, an epidemiologist at the institute, warned that they were not encouraging people to take up smoking, remarking that those smokers who do catch the virus “risk suffering more complications” than others. Scientists suggested it could be the nicotine in cigarettes that was behind the surprising results regarding infection, although more research is needed.

A study from China prompted Public Health England and the Centers for Disease Control and Prevention in the United States to put smoking on the list of 'risk factors' for coronavirus earlier in the crisis.