It all started with clinical observations that the proportion of smokers in hospitalised Covid patients appeared to be less than the general population.
"This has been observed, and it is accepted as an epidemiological fact, that when you take patient populations with Covid, the proportion of smokers is significantly lower than in the general population,” said Zahir Amoura, a doctor at the Pitié-Salpétrière hospital in Paris, told RFI. "Of course, that does not mean we think people should start smoking to protect themselves from Covid,” he insisted. “Smoking is a scourge. It’s important to repeat that.”