Right now, it’s hard to slip through the cracks. Since mid-January, all of mainland France has been in an epidemic phase for influenza. At work, in the family or among friends, everyone has noticed that the virus spreads very quickly from an infected person to his neighbor, spreading happily. In this context, a question arises: is the strain of flu introduced this winter in France. Is it more contagious than previous years? No, replies Pierre-Yves Bolle, professor of epidemiology…
Right now, it’s hard to slip through the cracks. Since mid-January, all of mainland France has been in an epidemic phase for influenza. At work, in the family or among friends, everyone has noticed that the virus spreads very quickly from an infected person to his neighbor, spreading happily. In this context, a question arises: is the strain of flu introduced this winter in France. Is it more contagious than previous years? No, answers Pierre-Yves Bolle, professor of epidemiology at the Sorbonne University and the National Institute of Health and Medical Research (Inserm).
“The strain of virus currently circulating is (H1N1), he explains. The flu virus is still evolving a bit but, for the moment, we have no reason to think it is any more virulent than other years. » According to the researcher, “Today, we are back to traditional influenza epidemiology”.
“Reconfiguring the system”
If the 2023-2024 flu pandemic is approaching pre-Covid-19 crisis norms, SARS-CoV-2 has nevertheless left its mark, admits Pierre-Yves Bolle. In 2020-2021, in the middle of the pandemic, “we didn’t get the flu,” he recalls. In adults, this absence may not cause a decline in immunity, “on the order of five to seven years” of protection after infection, the doctor recalls. But, he adds, the situation is different in children.
“They were less exposed during this period and at home, there are undoubtedly more people who were susceptible to the flu. » An explanation, perhaps, for the large-scale spread of the virus: if children are more easily contaminated, the adults around them are also at greater risk of being infected, especially since the reflex of inhibitory gestures has been significantly lost in recent times. year…
“Covid has significantly disrupted the respiratory virus epidemic”.
Pierre-Yves Boulay also noticed “changes in the types of expression” after cases of flu, especially fatigue and a cough that was more persistent than usual. “That’s one of the things we’ve noticed empirically,” he reports. We wonder: Is this a change in symptoms associated with the flu or another intervening virus? Is this a result of the lack of immunity we have during covid? These are questions we don’t have answers to today. »
The researcher and his colleagues are also trying to understand why, for two years, “covid is decreasing while influenza is increasing”, when “there is no direct competition between these two viruses”. Here again, the mystery remains: “It’s quite fair to say that Covid has greatly disrupted the respiratory virus epidemic,” he sums up. We are still in a phase where all these systems are adjusting in relation to each other, without us clearly understanding what the critical factors are. »
“We are seeing a significant increase in calls at Center 15. There is also a high demand for emergencies and we are seeing many cases in intensive care”
Hospital admissions are on the rise
One thing is for sure, this return to the classic flu pandemic is not good news. Every year, “2 to 6 million” French people fall ill, and 10,000 die, of which “more than 90%” are seniors aged 65 and over, according to official figures. Where are we in France at the moment? Tough, definitely, and the peak is not yet reached…
Between January 29 and February 4, Public Health France (SpF), the number of flu cases treated in community medicine remained stable, at a high level (18%), while an increase was recorded in hospitals. After emergency room visits, the virus now accounts for 3.1% of hospital admissions, a “high level of severity for all ages,” the SPF warns. “We are seeing a significant increase in calls to Center 15,” confirms Professor Charles Cazaneau, an infectious disease specialist at Bordeaux University Hospital. Emergencies are also in high demand and we deal with many cases in intensive care.
The good news this winter concerns the vaccine: its “effectiveness” is “between 60 and 65%” against the A (H1N1) strain, which is prevalent this year, says Bruno Lina, director of the National Virus Reference Center’s Respiratory Infections, Le As quoted by Point. It remains to convince the most vulnerable to take the plunge, while the vaccination campaign has been extended to February 29. At the end of November, only 42.8% of those aged 65 and over had been vaccinated, down from the previous year. “It is always useful to vaccinate until we reach the top,” recalls Pierre-Yves Bolle.
