In his service, questions rain, panic wins.
“I have South African, how is that possible?
"" I will finish in a sheave, that's for sure, "hears Doctor Benjamin Davido.
As for the fear of the Brazilian, let's not even talk about it… “Variants are the new pet peeve,” exclaims the infectious disease specialist at Garches (Hauts-de-Seine) hospital.
Opening of an ephemeral vaccination center, urgent dispatch of doses, massive screening… It suffices to see the reaction of the authorities in Bordeaux (Gironde), after the appearance of a cluster in the Bacalan district linked to a mutation of the English stock, to measure the concerns they have triggered since their arrival five months ago in France.
Right or wrong ?
“Their existence is a problem, we cannot dismiss them out of hand.
But yes, we are doing too much, concedes virologist Bruno Lina, one of the greatest experts on the subject.
We would almost forget that it remains the same virus.
In terms of mortality, the variants are not more dangerous.
We do not die anymore when we are infected with so-and-so.
"And nickname them" mutants "doesn't help ...
More transmissible, but not more deadly
Disagreements between scientists, contradictory assertions, hasty conclusions, the variants are in reality far from having revealed all their secrets. “The truth is, there are a lot of things you don't know. We must be wary of overly categorical remarks, ”warns Florence Débarre, CNRS researcher in evolutionary biology. In this vagueness, the rare certainties acquired concern the very first of them, the British. If an increase in its virulence is not demonstrated, "it is more transmissible, it has been established", continues the scientist.
From 36 to 75%, depending on the method used and the epidemic situation in the country.
The finding is there, it remains to be seen why.
Among the combination of hypotheses: the virus would stick "better" to the receptor of our cells, located higher in our respiratory tract, we would sputter more, its lifespan would be longer ... "There is a discipline, phylodynamics, who seeks to better understand the epidemic through the genealogical trees of viruses, notes Florence Débarre.
Researchers from all over the world are working on it.
They are real "profilers".
VIDEO.
Covid-19: vaccines are effective against "all variants of the virus", says WHO
For the contagiousness of its Brazilian and South African competitors, “there are solid elements but not fully confirmed.
And to say whether they are 1,2, 1,5 or 2 times more transmissible, one does not know it, insists Etienne Simon-Lorière, specialist in virology at the Pasteur Institute.
"As for the Indian," he continues, "it is really too early to say!
Even though the scientific community is arguing, there is still not enough data.
"
Horrified by the images of saturated hospitals and suffocating patients for lack of oxygen, public opinion and the media rushed to "the variant explanation", even if it means omitting the Indian context in which he invited himself.
The huge and popular Festival of Colors, massive travel for regional elections, religious gatherings on the banks of the Ganges.
Vaccines remain effective
The fact remains that B.1.617, its official name, has just joined the closed club of “worrying variants” listed by the WHO. Like his four running mate, he is suspected of worsening the epidemic and making it less controllable. The challenge, of size, is now to know if they do not outwit our antibodies, during reinfection or after vaccination. “But vaccines are effective! »Defends Doctor Davido, brandishing the results of a recent study carried out in Qatar. We learn that in Pfizer's match against the South African strain, it is the serum that keeps the advantage. “Yes, there is a slight decrease in efficacy, in the range of 10-20%, but it remains at 75%, better than any flu shot. It sets the record straight, loose the infectious disease specialist. But above all,the vaccine helps prevent hospitalizations and resuscitation. This is the only real data that should obsess us, us doctors. "
This weekend, the English health authorities revealed the results of a study showing that the vaccines from Pfizer-BioNTech and AstraZeneca-Oxford protect almost as much against the Indian variant as against the British.
Read alsoResults of PCR tests: you will soon no longer know which variant has infected you
For Dr. Davido, there is no doubt: in the face of mutants, "we play at scaring ourselves off", and we lose an energy that would be more useful for the deployment of vaccination, essential for precisely… not to see new ones appear! “We don't just play, we really have to worry about and monitor them,” tempers researcher Florence Débarre. If in itself being infected with a variant does not increase the risk of dying, as they seem to be more transmissible, they mathematically increase the number of patients. "However, the more the hospitals are saturated, the less the care of the patients is optimal", she points out. “Without them, the epidemic would probably not be over but surely much smaller. They gave it a new lease of life, ”summarizes his colleague from the Institut Pasteur, Etienne Simon-Lorière.
The virus is fighting for its survival
While several thousand variations have already taken place, the question arises of the virus's potential to continue to mutate.
This is what Bruno Lina, the virologist of the Special Covid Scientific Council, calls "the phases of evolution".
First, there was its "introduction" at the end of 2019. Then, its "installation" in February 2020, because of a first mutation, the D614G.
Then - this is the current stage - its "evolution" with a virus that struggles for survival as it is immunized.
And tomorrow ?
"I believe that the diversity will be reduced and that the variants will all end up looking alike," he says.
In the jargon, this is called evolutionary convergence.
"
The professor is still upset that day. And do not hide having difficulty in judging "good" the epidemic situation in France, while more than 12,000 new cases have been recorded this Saturday in the last 24 hours. His concern: that the introduction of the Indian variant would go quickly, too quickly, when he seems to be the only one today to be able to dislodge the very entrenched English clone. Is the Indian the new British? The second is installed this winter, the first could arrive this summer. The risk is clear: that a fourth wave will occur before the fruits of vaccination are harvested.