“In the spring, everyone will be convinced that everything is over, but not me!” Warns epidemiologist Renaud Piarroux

Between the records of contamination and closed classes on the one hand, the decline in intensive care admissions and the lightened health protocol on the other, it is difficult to see clearly in the middle of this fifth wave of Covid-19. Monday January 17, on France Inter, epidemiologist and member of the Scientific Council Arnaud Fontanet has reassuring news. “We have the feeling that the peak is passing before our eyes”, he says. Thursday is the government’s turn to announce some good news. Jean Castex and Olivier Véran present the timetable for a gradual lifting of the remaining restrictions. “This exceptional wave is not over, but I believe I can tell you that the situation is starting to evolve favorably”, even specifies the Prime Minister. However, on the same day, the Ministry of National Education announced that nearly 19,000 classes were closed, an unprecedented figure since the reopening of schools in the spring of 2020. And the number of contaminations reached a record on Tuesday, with 464,769 new cases of Covid-19 in the last 24 hours.

Epidemiologist Renaud Piarroux, head of the parasitology-mycology department at the Pitié-Salpêtrière hospital (AP-HP), says the situation should improve by spring. But, far from the ambient optimism, this field researcher wonders about the future of the pandemic and shares his fears about the emergence of new variants.

Franceinfo: Have we reached the peak of this fifth wave?

Renaud Piarroux: I think we have passed the peak in Ile-de-France since the number of new cases is lower this week than ten days ago. The region is ahead of the others. For the rest of the country, the number of new cases is very high. In all, on January 20, there were 5.6 million cases diagnosed in France just since the start of the year. Taking into account undiagnosed patients and those who already have effective immunity, we can estimate that we have passed the peak this week.

Hospitals seem to hold the shock. Why do we manage to cope better with this wave?

Hospitals are still suffering. I think we talk about it less because we have become used to these crisis situations. Severe forms are rarer, but we already have almost as many hospitalized patients as at the peak of the first three waves and many more than during the fourth wave. So there is a real problem at the hospital. And sometimes, a sorting must be done, especially in the south of France, where it is very complicated.

“Overall, what has really changed is the perception of the epidemic. By telling everyone that it’s not serious, that everything is fine, no one wants to hear about it anymore.”

Renaud Piarroux, epidemiologist

at franceinfo

And where does this change in perception come from?

From everyone. We are fed up. This comes from the public, from the population, from the press too. At the end of December, the Pasteur Institute published several forecasts, some of which were frankly catastrophic. Among all the scenarios, only one model predicted that not much would happen. But it is the one that has been highlighted in the press. Some time later, the Pasteur Institute clarified its calculations and this “optimistic” model was discarded. But the press did not return to it.

It is also a perception that is supported by the government. We keep the schools open so we can say, “Look, we saved everybody’s life.” Finally, even the doctors are fed up. They prefer to look at the most optimistic forecasts even if they know that it is also necessary to be prepared for more complicated scenarios.

The number of deaths is not the indicator that is most followed at the moment, unlike the number of daily cases or the number of hospitalizations…

And yet, they are increasing at the moment. So it’s not quite as high as a year ago. During the winter of 2020-2021, we were around 300 to 400 daily deaths. There, we are between 200 and 250 deaths per day. It is still not negligible. Yet no one talks about it. Again, we don’t want to see it.

What about herd immunity?

Already, the immunity we have acquired, thanks to vaccines and contamination from previous waves, is reflected in the fact that there are fewer serious forms. But will this immunity allow us to resist new variants? I do not know. Omicron shows us that there can be a significant wave, at least at the level of transmission, in a context where almost the entire population is vaccinated or has contracted the disease. And we are already seeing variants of Omicron, like in Denmark.

Will Covid-19 become a form of seasonal flu after Omicron?

I’m not saying that’s wrong. Nor that it’s true. In fact, I don’t know. And I don’t understand how anyone can know that. First, because Delta has not disappeared. Then, because we don’t know what the behavior of a virus like Omicron might be. This variant is so contagious that epidemics are currently almost simultaneous around the world. Maybe he will disappear if there is no one left to catch him. I also don’t know if another variant will arrive. And if that happens, I’m not sure it’s less virulent than Omicron. Anyway, the contagiousness of these coronaviruses poses a big problem. In the case of an influenza epidemic, only 10% of the population is affected in a season. With Omicron, we have changed scale.

Do you have any certainties today about Sars-CoV-2?

This virus has surprised us from the start. It has become extremely contagious. This behavior is very unusual. Furthermore, we have never found the animal source that would have allowed this bat virus to infect humans. I think that we must now consider the involuntary leak from a laboratory as a hypothesis to be seriously investigated.

Do you think this virus can still have surprises in store for us?

Yes. I do not rule out the hypothesis that the situation is improving. For the coming weeks, we have a bit of visibility and we can say that we will approach spring in a much better situation. In March and April, with the return of spring, everyone will then be convinced that everything is over. But not me !

Since I don’t think people are going to rush for a fourth dose of vaccine, we will have, after four to six months, again a population capable of transmitting the virus. The question is what virus will we be dealing with then. Will it be Omicron, Delta or another one? And if so, what will its characteristics be?

Given the number of people infected today, it would still be surprising if there were no new variants. But we won’t see them right away. These variants are generated in immunocompromised people who harbor the viruses for a long time. Some will only emerge in a few months.

You sound very pessimistic…

It’s not me who’s pessimistic, it’s the others who are optimistic. And I’m only half kidding. People are fed up. They only want to hear optimistic news. But in reality, no one can predict what will happen in more than two months. The important thing is not to be optimistic or not, it is to consider the scenarios and prepare for them.

Does this mean that people should expect to be vaccinated regularly?

I fear that most people will come out of this wave with the belief that it is no longer necessary to get vaccinated. Adherence to vaccination will be complicated, since they hear all day long that Omicron gives them immunity. We will emerge from this wave with a huge vaccination rate. Already 32 million people have received their booster dose. But that’s not why people are going to get vaccinated every three or four months. This is also not conceivable. As a result, immunization against transmission will not last.

Does this mean that we are forced to wait? That we haven’t found the right strategy yet?

The “zero Covid” strategy has failed, except in China, where it still holds. This strategy could have been attempted after the first wave, when the virus was less contagious and less virulent. But the politicians didn’t want to, and since we all live on the same planet, the countries that had made the effort had to backtrack with the arrival of increasingly contagious variants. We left too much space for the virus to proliferate and mutate. Many countries that used to control the situation now find themselves in trouble.

On the other hand, the strategy of living with the virus is not a planetary success either. We now see that this meant the waves would come and go. We are in the fourth or fifth depending on the country, with, each time, a disorganization of care. There is nothing to brag about.

“If, in the summer of 2020, we had been told that by letting the virus go, we would have a rotten winter with 300 to 400 deaths a day, and then that vaccination would only be a transitional solution, I am not sure that people would have thought that was a great prospect.”

Renaud Piarroux, epidemiologist

at franceinfo

The very optimistic speeches of recent days, the studies of other countries on Omicron… we felt rather reassured.

Yes, what we see is that the numbers go down after a while, and in France, we get there. In South Africa, it has gone down, it has not yet gone down to zero, we must continue to monitor. In England, it is also falling, but in Denmark, no. You can see that nothing is set in stone. We just have an idea of ​​what’s going to happen in a month or two. Here we can be optimistic. It’s the aftermath, the problem.


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