Covid-19: the Institut Pasteur describes the different scenarios of the effects of Omicron in France – BFMTV

In a report dated Monday and posted online this Wednesday, the Institut Pasteur makes public its models for the hypothetical effects of Omicron in France. The researchers paint different scenarios, adjusted to various levels of severity and transmissibility of the new variant and advise the authorities on the measures to be put in place to limit the shock.

The expression is from the Minister of Health, this Wednesday, in front of the deputies of the Commission of Laws: Omicron is spreading in France like a “tidal wave”. Researchers at the Institut Pasteur are therefore trying to get their heads out of the water in order to see more clearly about our immediate health future.

In their new report, dated Monday and posted online two days later, they are thus making public the lessons to be drawn from their modeling work. The idea is to review – thanks to a mathematical model – the different scenarios possibly caused by the appearance of the new variant in the country, by associating with the latter different levels of severity, transmissibility and by imagining the response of the authorities. .

For the Institut Pasteur, the Omicron episode could remain “manageable” if it actually turns out – as various foreign experiences depict – more contagious but less dangerous than the Delta variant, on condition that measures “of intensity are determined. intermediate”. Scientists are calling in particular for an acceleration of the recall campaign and a reduction in contact between our fellow citizens.

The most probable hypothesis

But before reaching this conclusion, Pasteur’s experts took care to surround their documents with the usual precautions. “Given the significant uncertainties regarding the severity and transmission advantage of the Omicron variant over the Delta variant, it is not possible to precisely quantify the impact that the Omicron wave will have on the healthcare system,” admits even the Institute which specifies counting on new and beneficial data within one to two weeks.

This nebula does not prevent us from listing the scenarios. Pasteur first takes up the most probable hypothesis as drawn by several foreign, British or South African studies. In this one, Omicron’s severity is 80% lower than Delta’s ferocity, and this one is moderately more contagious than this one. In such a situation, we could see peaks of 2,700 daily hospitalizations if nothing more is done to curb the circulation of the virus. A total that a reduction – of the order of 10% and 20% respectively – in contacts between the French could reduce to 1900 or 1400 daily admissions.

On the other hand, if it appears that we are still underestimating Omicron’s gain in contagiousness on Delta, this peak would peak at 4,400 hospitalizations per day, in the absence of a suitable response from the authorities or 2,700 if they hardened the arsenal in place.

Finally, if Omicron proves to be barely more contagious than its predecessor, the daily peak in hospitalizations would not exceed 1,700 in the worst case, according to the researchers.

Disaster scenario

They then imagined another possibility: an Omicron presenting the same gravity as the original strain but a discount of 54% compared to Delta. A very marked increase in the transmissibility of one variant to another could then lead us to bed 5,000 people every day in the absence of measures, ensures the document.

On the other hand, a reduction in contact between individuals would maintain this peak around 2500 in the case “where the transmission advantage of Omicron is intermediate or low”.

The health benefit of the recall

Apart from a decrease in interactions between our compatriots, the Institut Pasteur suggests another tool to round off the epidemic peaks of the coming weeks a little: a significant strengthening of the recall campaign.

If the number of these inoculations fell from 800,000 to 1.2 million per day, specialists consider a decrease in the daily hospitalizations envisaged of “9 to 17%” possible. A reduction in the increase in hospitalizations which could even range from “17 to 35%” by convincing “90% of unvaccinated adults”.

In any event, Pasteur therefore dwells on the following perspective: “By comparing different scenarios, we believe that the Omicron wave could remain manageable with intermediate intensity measurements if the intrinsic severity of Omicron
is about 80% weaker than that of the Delta variant. “

Towards a social “disruption”?

However “manageable” it may be, the crisis promises to be painful and researchers are not hiding it. Thus, they pose that “hundreds of thousands of French people could be infected daily in January”.

An estimate that not only has nothing more of a blueprint, but already seems a little out of date. This Wednesday, Olivier Véran announced “208,000” positive diagnoses over the past 24 hours. The day before, already, it was nearly 180,000 French people who had been contaminated according to reports alone.

The report tempers by noting that these infected would be “in the vast majority of cases with mild symptoms” but points all the same: “the absenteeism resulting from this wave of infections risks disrupting the functioning of the company”.