Covid-19, a simple flu? This comparison was heard a lot at the very beginning of the epidemic, two and a half years ago, when scientific knowledge was still lacking on the disease. Since then, 152,000 people have died in France. Today, while the number of covid cases is on the rise again, this analogy between these two diseases is making a comeback. In question ? A concern that seems to have fled from the spirits. This phlegm is also shared by many doctors, such as Pierre Tattevin, head of the infectiology department at the Rennes University Hospital: “As for the previous wave, we have the impression that the impact on the hospital is not going be that important. Admittedly, there are a lot of contaminations, but the disease leads fewer people to be hospitalized, especially in intensive care. Until you see the annual death toll from covid getting closer to 10,000 flu-related deaths ?
Two respiratory viruses dangerous for fragile people
For Antoine Flahault, epidemiologist and director of the Institute of Global Health at the University of Geneva, it must be recognized that covid shares some analogies with the flu: “These are two RNA viruses which are transmitted by aerosol. These respiratory viruses cause apparently mild illnesses in a large number of people, but cause complications preferentially in the elderly or with comorbidities. Their vaccine is not sterilizing (in the sense that one can contract the disease by being vaccinated) but protects against serious forms. It is viruses that circulate massively among children that are driving epidemic waves in the population, ”he says. For his part, Pierre Tattevin, believes that “currently, one could almost say that covid-19 makes most patients less sick than the flu. Many are found to be positive because they have been contact cases but do not show symptoms.
“We have never seen four waves of flu in one year”
However, the two doctors consider that the comparisons should stop there. “We have never seen four epidemic waves of influenza, including one in summer, during the same year in France and in Europe”, remarks Antoine Flahault. “More than 30,000 deaths from covid were recorded in 2022 alone, ranking the disease among the leading causes of death in France. Except maybe during the Spanish flu pandemic in 1919this has never happened, in living memory in France, with the flu before, ”continues the epidemiologist.
But the main difference concerns the long forms of the disease: “While all viruses seem to be capable of causing post-infectious syndromes of various kinds, les covid longs are unprecedented in the register of respiratory virus diseases”, recalls Antoine Flahault.
“There are so many differences between covid and the flu, that it does not add much to compare them. In particular because of the long covid which remains a real source of concern”, agrees Pierre Tattevin. “If there was a disease to which we could hope one day to compare covid, it would rather be the common cold, which, too, is caused by coronaviruses. We have the impression of going towards a covid virus which will rather remain at the nasopharyngeal level and which will not give a lot of pneumonia, ”he continues. The Rennes infectiologist nevertheless warns against any excess of optimism: “We are not there yet! »