Since the beginning of March, coronavirus contaminations have started to rise again.
An epidemic resumption caused by the BA.2 sub-variant of Omicron, more contagious than the previous strains.
But the lifting of health restrictions also contributes to the increase in contamination.
At the start of spring, when the weather is nice and rather warm, and we are getting back to enjoying life before, without masks or health restrictions, the Covid-19 is still acting up.
Since the beginning of March, Covid-19 contaminations have been on the rise again.
If we are far from the peak of January, when the threshold of 500,000 daily cases had been crossed, the health situation shows a resumption of the epidemic.
On Monday, the seven-day average stood at 89,763 daily cases, against 65,882 cases on average a week earlier (+ 36%), and 52,715 the previous Monday.
Why, despite the return of fine weather and rising temperatures, is the epidemic starting again?
Should we be worried about it?
Is this recovery the sign of a fifth-wave pullback, or the mark of a sixth surge in two years of the pandemic?
A wave of sub variant of Omicron BA.2
This increase in contamination is due “to the dissemination of the BA.2 sub-variant of Omicron, explains to
Mircea Sofonea, lecturer in epidemiology and evolution of infectious diseases at the University of Montpellier.
In December – January there was a Delta wave and an Omicron BA.1 wave which overlapped.
We have seen this more or less clearly in hospital dynamics, but in certain regions such as Occitanie, it has been quite clear: with a Delta peak then an Omicron BA.1 peak.
The BA.2 sub-variant was already present during the BA.1 wave.
First quietly, with only a few cases identified.
Within weeks, BA.2 replaced BA.1.
"The BA.2 sub-lineage now represents 57% of Omicron sequences", confirms Public Health France in its latest bulletin.
"BA.2 is more transmissible than BA.1 by around 30%", notes the Scientific Council.
Thus, “from a purely genetic point of view, this is a new wave, since it is not a cover of BA.1.
From this point of view, I would even speak of the seventh wave.
Is this enough to say that we are in a different episode of the epidemic?
Yes, says the epidemiologist.
Even if between the two waves, certain indicators did not drop drastically: between wave BA.1 and wave BA.2, the figures did not fall below the threshold of 1,500 patients in critical care targeted by the government, observes he.
So, fifth wave to extend, sixth or seventh… “what should be called “wave”, it is rather a recovery which lasts a certain time, tempers Mircea Sofonea, with an active circulation and a reproduction rate – the famous R – greater than 1 for several weeks, in a health and genetic context from a different viral point of view.
And there, this is what we observe: not only are we dealing with BA.2 and no longer with BA.1, but in addition we have a different health context since the barrier gestures have been abolished ”.
"The effect of the relaxation of barrier gestures"
Because everyone – or almost – quickly regained a taste for life without a mask.
Consequence: in pharmacies, in recent days, swabs have been drawn more frequently, and the test positivity rate is climbing faster than the thermometer.
“We have seen a clear difference in recent days: we are doing a lot more tests, and many are positive”, we breathe in a Parisian pharmacy.
Meanwhile, daily hospital admissions for coronavirus rose more than 9.6% in a week.
Was the lifting of restrictions on March 14 premature?
“There will never be a consensus on the right time to do it, judge Mircea Sofonea.
Especially since the government has had the objective, with the appearance of Omicron, of living with the virus without additional restrictions, as we saw during the epidemic peak this winter.
These are markers of the fact that the executive wishes to minimize prevention vis-à-vis the circulation of SARS-CoV2 in France ”, which also displays significant vaccination coverage.
“This relaxation of measures in the context of an election campaign is consistent,” he continues.
In another context, the review clause would certainly have been used to reinstate certain restrictions.
Obviously, this will not be done in the next few days”.
“Our projections certainly show the transmissibility advantage of BA.2, but also the effect of the relaxation of barrier gestures, insists the epidemiologist.
A gradual relaxation, already before March 14, which marks a decline in general vigilance.
And that makes the machine run wild again.
“This progression of the relaxation of barrier gestures induces a progression of the basic transmission rate of the virus, independently of the greater transmissibility of BA.2”, underlines Mircea Sofonea.
The problem, “is that the models can't tell how far this level of increase in base transmission will plateau.
We can only establish scenarios, he explains.
In the first, based on what is observed today, there is no flooding of hospitals.
On the other hand, if the R exceeds 1.5 for several weeks, this can cause a problem locally.
For the moment, there is no reason to worry at the hospital level, but the epidemic is neither behind us nor benign: there are still hospitalizations in critical care, deaths and long Covids , even with Omicron”.
However, in its latest opinion of March 14, the Scientific Council is not alarmed: “the number of hospitalizations will increase temporarily in the coming weeks”.
But “in all the scenarios explored, the peak remains much lower than the January peak”.
For Mircea Sofonea, this recovery “underlines more than ever the importance of wearing a mask in the face of this sub-variant more contagious than all the previous ones.
The barrier gestures will reimpose themselves spontaneously: everyone will be more careful when there are more cases around us”.
Coronavirus: Contaminations continue to increase over a week
Covid-19: WHO concerned about new outbreaks of contamination around the world
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