Jean-Michel Claverie is a virologist and public health specialist at the University of Aix-Marseille.
While the number of new cases of contamination with the English variant continues to increase, he considers a flash vaccination campaign all the more essential.
After the English variant of Covid-19, the South African variant, a third mutant virus has just been detected in Japan on people coming from Brazil… Should we be worried about these clones?
JEAN-MICHEL CLAVERIE.
These much more contagious mutants must not take precedence over the current strain.
This is why the government has decided to give priority to vaccinating the regions where the virus circulates the fastest.
With the vaccines we have, we are now clearly in a race against these mutants.
So far, these mutants don't appear to degenerate into more deadly strains, but it can happen.
Why does a virus mutate?
This is its way of surviving, each time a virus enters your cells, it changes just by replicating: compared to the initial virus that infected you, there will be at least one or two differences .
Fortunately, not all the mutations detected to date have fundamentally changed the identity card of the Sars-Cov-2.
It still uses the same key to get into our cells, the Spike protein, the one that all vaccines in existence or in development target.
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It's good news.
But that does not prevent the need to speed up vaccination… Currently, we are on a rate of 15,000 new daily infections in France, while not everyone is being tested.
This is a worrying level of viral circulation.
The more you let people get infected, the more you run the risk of developing new strains of varying degrees of concern.
One day or another, one of them will end up bypassing the immune response induced by current vaccines or going through the back door using a new key.
The technique of messenger RNA vaccines will cope?
It's fantastic technology.
With it, in fact, in a few weeks, you can change the design of the vaccine.
But, unless you take reckless risks in terms of public health, if the virus radically changes its angle of attack, the vaccine will have to be tested again.
Those of Pfizer and Moderna took 8 to 9 months to complete, trial phases included.
It was already a feat.
Can we really go faster?
I ask to see.
What would be the ideal rhythm of the vaccination to catch up with the virus?
To do this, at least 100,000 people should be vaccinated per week.
The sooner we get closer to the collective immunity threshold of 60% to 75% of the population, the less time the virus will have to cunning and adapt to the vaccine pressure.
Vaccines are good, but to relieve the pressure on hospitals, we should now be able to couple them with antivirals as effective as those found for people infected with HIV.
This would at least limit the number of severe forms which will mechanically increase if the mutant forms, which are much more transmissible, become, as in the United Kingdom and South Africa, the dominant lines.