The increase in the number of coronavirus cases does not call into question the end of health restrictions, including the disappearance of the mask in certain places.
Everything was going well though. For six weeks, all the epidemic indicators were green. The virus was losing a little more ground every day. But, while the government announced, on March 3, the lifting of all restrictions for March 14 (except the wearing of masks in transport), the virus has been showing signs of resurgence for a few days. The number of daily cases is now on the rise again. There were just over 52,000 cases on Sunday March 6 (calculated on an average of 7 rolling days), against more than 63,000 this Saturday.
The decline in hospital and intensive care unit admissions is also slowing and appears to be heading towards a fairly high plateau. The objective of 1,500 people taken care of in intensive care, yet set by Olivier Véran to lift the health pass, should not be reached for several days (or even weeks) if we are to believe the data published by Public Health France, which show of 1,857 people in critical care units (figure combining admissions caused by Covid and patients admitted for another reason, but tested positive, and taking into account intensive care units as well as critical care).
It is difficult to know with certainty the causes of this recovery. Several factors seem to come into play. The Omicron sub-variant, BA.2, now the majority in the country and more contagious, has been singled out. “We see elsewhere in Europe or in certain French regions that the BA.2 has been in the majority for some time without the dynamics being reversed, nuance Justine Schaeffer, epidemiologist at Public Health France. This sub-variant surely contributes to the current revival, but does not explain it alone.
At the same time, we note that the northwestern part of the country was the first to be affected by this start of recovery, thus coinciding with the start of the school year for the February holidays for this area. “The incidence increased first among the youngest, so the resumption of classes undoubtedly favored the circulation of the virus, Judge Justine Schaeffer. But there is a recovery in departments which had a later start. Here again, the simple resumption of prices cannot on its own justify this beginning of a rebound.
“A particular context for the lifting of restrictions”
Moreover, France is not the only one affected by this revival. Most European countries are indeed seeing the number of cases start to rise again. In England, hospitalizations are also increasing. Seasonality can therefore be taken into account, especially since it was around the same time that the epidemic restarted a year ago.
“We know that the most favorable temperature for the virus is between 5 and 10 ° C, comments Simon Cauchemez, head of modeling teams at the Institut Pasteur and member of the Scientific Council. The weather can play a role in this recovery. But the combination of all these factors is also part of a particular context of the lifting of restrictions. Arguably, these behavioral changes play the most important role.”
In a report published on February 21, Simon Cauchemez’s modeling team at the Institut Pasteur mentioned a possible recovery around mid-March, in the event of a significant change in behavior. “It was envisaged that the drop in the number of cases and the arrival of spring would surely lead to the lifting of restrictions and a strong relaxation, explains Simon Cauchemez. We can see that this relaxation occurred one to two weeks ahead of what we anticipated. Wearing a mask is no longer compulsory in places subject to the vaccination pass since February 28. And, if the end of the mask and the health pass is only planned from Monday March 14, the announcement on March 3 of this deadline undoubtedly accelerated this relaxation.
Since the start of the epidemic, we have noticed that the impact of the measures is felt before they are implemented. The French anticipate in one direction, as in the other, the future recommendations. The contaminations had thus slowed down a few days before the confinement of November 2020, the day after the intervention of Emmanuel Macron. We also note at this time a resurgence of the flu epidemic, yet very well controlled until then. By lowering vigilance on the Covid, the other respiratory viruses also circulate more actively.
“The current trajectory corresponds to that which we had modeled by considering that the French would increase their contacts by around 40% compared to the level of January, continues Simon Cauchemez. The whole question now is to what extent the lifting of restrictions on Monday will increase our interactions.
The scientists published an update of their models last Thursday with several scenarios according to varying degrees of relaxation. The good news is that, even in the worst-case scenario, the peak of this rebound would be expected by the end of March and would remain much lower than in January, even though no restrictions will no longer be in place. vigor.
A life-size test
“It would be very surprising if the lifting of the restriction on Monday did not generate a new rebound, judge Simon Cauchemez. But I think we can move away from our most pessimistic scenario, because the relaxation has, at least in part, already taken place. The rate of circulation of the virus should continue to progress and could bring us into a scenario that would correspond to a 75% (or even 100%) increase in interactions compared to January. But the immunity acquired by vaccines and contamination should protect us and avoid overcrowding in hospitals.
This beginning of a rebound is in a way a life-size test for the government and its “living with the Covid” strategy. If, as predicted by the Institut Pasteur model, the next wave is absorbed, we can look quite calmly to the months to come. Conversely if we are faced with a wave equivalent to the previous ones “that would be quite depressing”, judge Simon Cauchemez. Acquired immunity would simply not be enough to protect us.