With 4,579 positive cases identified in 24 hours, this Monday, against 3,443 seven days earlier, an increase of 33%, the arrival of a new wave of covid-19 in France is no longer in doubt. This rise in figures has been observed for six days.
In Brittany, the incidence rate, from September 29 to 4, reached 181 cases per 100,000 inhabitants, up slightly from that of the previous week, noted Public Health France, Friday. It is one of the highest in France.
Immune decline against infections
Not a surprise. Epidemiologists anticipated, from the start of summer, an eighth wave in the fall, of a virus which is transmitted mainly by aerosols: “With the start of the school year, the resumption of activities, in particular professional, the less clement weather, people are more likely to live indoors,” notes Philippe Amouyel, professor of public health at Lille University Hospital.
Another reason for this resurgence of the epidemic, “the immune decline of the population against infections”, adds Mircea Sofonea, lecturer in epidemiology and evolution of infectious diseases, at the University of Montpellier. “It corresponds to the loss of protection conferred by vaccination or a previous infection. It decreases over time and, alas, reaches relatively low levels, around 10%, after five months. »
“We are starting to be distant from certain vaccinations, especially for the youngest, for whom the recommendation for a fourth dose has not been put in place”, adds Philippe Amouyel.
Unlike the two previous waves which saw new variants come into play, it is the Omicron sub-lineage, BA.5, already at work in June, which is still playing the spoilsports in September. It is currently responsible for 95% of contamination in the country and it is its descendants BA.5.2 and BA.5.2.1 that are progressing the most in France. Challengers such as BA.2.75, well established in India, have only been detected at low levels in France.
A “very low” risk of saturation of hospitals
What amplitude could this new wave reach? “The current slope is not enough to anticipate the height of the peak”, considers Philippe Amouyel. Epidemic modellers navigate on sight, Mircea Sofonea castigating the current lack of financial investment from the State for epidemiological research on covid-19: “With more means to operate and adjust our models, which is more and more difficult, we could have visibility for a month, ”he believes.
The fear of seeing hospitals overloaded remains moderate: “Thanks to the protection against serious forms offered by vaccines and old infections, the risk of saturation at the national level is still very low”, reassures Mircea Sofonea.
As for barrier gestures, wearing a mask and ventilation, in particular, it seems unlikely that the government will return to the coercive measures of 2020 and 2021. “I think it would not be reasonable to have an order that falls from the top. Advice, yes, but the French must learn to manage barrier measures themselves, whether for covid or other diseases, ”assures Philippe Amouyel.
letelegramme Fr Trans