Coronavirus: With Omicron, beware of the conflagration or “Christmas miracle”?

Are we witnessing a real miracle of Christmas ? In France, while contaminations with coronavirus explode – more than 70. 000 new cases Tuesday, 14% more than last week -, hospitalizations (1. 239 on average per day over the week, 5% more than a week ago), and especially resuscitation ( 257 admissions to critical care per day on average over the week, increase of… 0% compared to seven days ago) are stagnating.

An atypical decorrelation in the history of the epidemic in France. Is it the hope of a way out of the crisis, or the calm before the storm? 19 Minutes takes stock.

Is such a decorrelation normal ?

There is a classic lag, of several weeks, between the increase in the number of cases and that of hospitalizations then resuscitations. Allow about a week to ten days for the increase in cases to translate into an increase in hospitalizations, and about the same duration for the increase in resuscitations to occur. Only here, the cases have not stopped increasing for weeks, and the only explanation for the temporal interval no longer holds.

“This is a fairly new phenomenon, but it do not forget that it is very difficult to compare the periods ”, warns Dr. Franck Clarot straight away. Not the same vaccination coverage , not the same immunity in the population… A rather similar phenomenon however took place during the fourth wave this summer, with a large difference between the cases and the number of hospitalizations and resuscitations, probably due to the vaccine. But here again, the comparison quickly reaches its limits: “It was summer, we lived outside”, notes Franck Clarot. An outdoor life much less conducive to contamination , which is further proof of the “exploit” of this month of December, which made the share beautifully in closed places.

Yannick Simonin, virologist at the University of Montpellier, offers an explanation: admittedly, the cases are on the rise, but the incidence is decreasing in those over 50 years, the population most at risk of ” be hospitalized or even be admitted to intensive care. These seniors represent 65% of hospitalizations and 40% of critical care since the start of the crisis, according to Public Health France. And their declining incidence would be due, according to the virologist, to the famous booster dose : “This category of the population is that having the best vaccination coverage: 65% have already received their booster dose, which greatly reduces the risk of hospitalization and entry into intensive care. »

Does Omicron play a role in this decorrelation?

The increase in cases in France is notably driven by the variant Omicron , which would represent 20%, according to government spokesperson Gabriel Attal, Tuesday. However, several studies suggest that Omicron is less virulent than the Delta variant .

While the UK has seen an increase in cases of 92% in one week, hospitalizations there increased by… 2% at the same time. The media Politico also unveiled on Wednesday the conclusions of a report from the British Health Agency expected by Christmas, that “Britons who get sick with Omicron are less likely to become seriously ill than those who caught Delta”. A finding close to that established in South Africa. The country, the first to be massively affected by Omicron, has not seen a gigantic increase in hospitalizations and deaths. Differences between populations (median age of 20 years in South Africa, against 28 in France) had however prevented conclusions from being drawn for Europe.

A report from the Statens Serum Institut , in Denmark, the king of sequencing and heavily affected by Omicron, establishes that only 0.6% of people infected with Omicron, from 22 November to 15 December, were hospitalized, compared to 1 , 4% of those contaminated by Delta. Likewise in France, Omicron is very present in Paris – it would already represent more than 50% of cases. However, in the capital, while the cases explode, the number of entries in sheave is decreasing.

Should we then see a link? “It’s probably a bit early to say it, tempers Franck Clarot. For the moment, there is no reason to think that Omicron would be more virulent, nor even as virulent as Delta ”. Be careful, therefore, in the face of an unpredictable epidemic.

Can Omicron be a blessing for the epidemic?

These “encouraging” news – which require confirmation – may suggest that Omicron would ultimately be a “good” thing: a variant that would contaminate the population, naturally immunizing against future infections, but without sending in sheave A little too “Christmas miracle” to be true? The reality will undoubtedly be much more nuanced.

Yannick Simonin invites in any case to keep our feet on the ground: “We still lack data to be categorical on the influence that Omicron may have. If we want to be optimistic, there are reassuring elements in recent days. The booster dose appears to be very effective in preventing severe forms, but also infection with this variant. In addition, until now, Omicron has not been associated with waves of hospitalization in the various countries facing it. We have to wait for consolidated data to know whether, in the end, this variant is much less formidable than what one might have feared initially. ”

Same tone with Franck Clarot, especially since even if the variant turns out to be less virulent, it is not benign for all that:” We cannot seek to obtain natural immunity at the cost of tens of thousands of deaths. ” So let’s all remain cautious during this holiday season , with a third dose, gesture fence. And ventilation despite the cold.