Is the eighth wave of Covid-19 slowing down? At least that is what the indicators of the epidemic seem to show. Like the incidence rate, which “stabilized at a high level nationally after five weeks of increases”. This reference indicator for monitoring the evolution of the epidemic reported 567 cases per 100,000 inhabitants on October 17, according to the weekly bulletin published on Thursday, October 20 by Public Health France. A figure certainly high, but which stabilized before it started to fall in recent days.
If the peak of contamination seems to have been reached (more than 53,000 daily cases on average over the last seven days), this eighth wave of the coronavirus, however, continues to send thousands of patients to the hospital (6,556 new admissions in the week of 10 . October ) and in the intensive care unit (up 8% compared to the previous week). And Covid-19 continues to kill hundreds of people every week: 390 patients died in the week of October 10, 23% more than the previous week. What can be learned from this autumn wave? Franceinfo takes stock of epidemiologists.
The peak of pollution coincides with the start of the school year
We note, on the graph below, that the incidence of the Covid-19 epidemic began to rise again at the beginning of September. “The correlation is perfect with the start of the school yearpoints out epidemiologist William Dab, contacted by franceinfo. We saw the surge restart just a few days later.” The former director-general mentions several examples of measures that have not been sufficiently implemented to slow down this eighth wave: ventilation systems in closed places, at work or at school, or even mandatory masks in transport and closed places.
The rate of change in the number of pollution since the beginning of September confirms William Dab’s observation. There is clearly a sharp increase in cases (represented in red on the graph below) from the week after the start of the school year, which occurred on September 1st. “This is the result of an epidemic recovery mainly due to Omicron BA.5”, explains to franceinfo Mircea Sofonea, epidemiologist at the University of Montpellier. And this because of two phenomena that increase the risk of contamination: “that immune decline and the autumn season.” “AWith shorter and cooler days, the population increases their time indoors, where infection is favoured.”explains the specialist.
This back-to-school wave could well end in the All Saints holiday, which begins on Saturday 22 October for the whole country. They have “previously, the circulation of Sars-CoV-2 slowed down”, says Mircea Sofonea. But we must not declare victory too quickly. An increase in cases may follow due to “school resumption, spread of BQ.1.1 [un nouveau variant qui émerge en Europe] and the beginning of the winter season”warns the epidemiologist.
The main lesson of this eighth wave is also good news: the number of hospitalizations during the period was “among the weakest” compared to previous waves, notes Mircea Sofonea. IN “particular” regarding intensive hospitalizations. A drop is attributed to the vaccination coverage rate, which as of Oct. 17 was 82.5% among people aged 65 and over, according to Public Health France. This lower number of admissions “is a sign that vaccination protects well against severe forms in the long term”emphasizes Mircea Sofonea.
In addition to the vaccination rate, it is the spread of the Omicron variant that explains this reduced number of admissions. “This is unheard of in epidemiology: at least 70% of people have an infection with Omicron. But we must not think that it is over.”warns William Dab. “Many large studies have shown that the more infectious episodes we have with this virus, the more our thread of complications increases. Especially diabetes, myocardial infarction and cerebrovascular accidents.”, emphasizes the epidemiologist. According to him, we must therefore get the idea out of our heads that Covid-19 is no longer dangerous, because it would send fewer people to hospital immediately. “This virus will leave traces in the medium and long term. The more we can avoid being polluted, the better.assures William Dab.
Less severely affected children
Other good news from the children’s side: this eighth wave, caused mainly by the BA.5 subline of Omicron, has resulted in very few Pims, those pediatric multisystem inflammatory syndromes that affect certain children with Covid-19. “Five cases have occurred since the beginning of August”notes Public Health France in its bulletin published on October 20.
This sharp decrease in the risk of Pims “can be mainly explained by a lower capacity forOmicron to trigger hyperinflammation“noted the authors of the American scientific journal Jama Pediatricsquoted in The Parisian. Another hypothesis: that Pims “occurs especially after a primary infection”states Christelle Gras Le Guen, president of the French Society of Pediatrics (SFP), to the daily newspaper.
“In recent weeks, the development of the epidemiological situation in children under 18 has been characterized by a decrease in incidence”, for its part confirms Public Health France. The number of pediatric hospitalizations due to Covid-19 has been stable for a month. In most cases, children under the age of 1 are hospitalized. In the week of October 10, these toddlers represented 59% of hospital admissions for 0-17 year olds and 48% of critical care admissions.