The 7th wave of Covid-19 which is beginning to sweep over France is worrying as vacation departures approach.
The health authorities are beating the reminder to encourage the most vulnerable to receive a new booster vaccine now, without waiting for future vaccines which will target the latest variants more.
As early as January, an opinion from the Vaccine Strategy Guidance Council (COSV) recommended that severely immunocompromised people, as well as their relatives, receive an additional booster dose of vaccination.
On March 14, French people over 80 were asked to do a second booster, often a fourth dose in fact.
On April 7, this recall was opened to over-60s.
Appointments are on the rise
But according to the latest official figures, less than a third of them had received it ten days ago.
Those over 80 eligible were 30.1%, those aged 60-79 eligible 26.5%.
According to Doctolib, the main dating site, reservations for booster doses, which had been stagnating for two months, have started to rise again.
At this time, there is no recommendation for a new booster for the general population.
If a Frenchman under 60 wants a fourth dose, he will not be refused.
But the authorities are calling first on those who have not received a third dose to do so.
What is the purpose of this reminder?
We now know: the protection of vaccines against infection erodes after about 10 to 12 weeks.
On the other hand, they remain effective for several months against the risk of serious forms of the disease.
To limit as much as possible the deaths linked to Covid and a new saturation of hospitals, the health authorities therefore insist on a vaccination booster for the most fragile, whose immune system and memory are less robust.
Some French people wonder about the advisability of waiting for the fall and the arrival of new vaccines for their booster.
“I will answer very clearly: you must get vaccinated now if you are over 60 and have a certain number of risk factors”, decided Thursday on RTL the president of the Scientific Council Jean-François Delfraissy.
" Why ?
Because these vaccines exist, they are effective against the BA.5 variant on the occurrence of serious forms, and the new vaccines that will be available to us will have an availability that we do not yet know and that I rather estimate in October or early November,” he said.
What do we expect from new vaccines?
“We would like to have a more effective vaccine on the transmission of the coronavirus, explained to AFP the epidemiologist Antoine Flahault.
Today, this so-called "sterilizing" effectiveness is very modest and does not prevent the waves from spreading.
It is on this immunity that manufacturers are working with their new vaccine formulations”.
At the moment, mRNA vaccines are based on the original strain of SARS-CoV-2.
But many variants have appeared, increasingly resistant to the immunity conferred by these vaccines.
Pfizer-BioNTech and Moderna recently announced that their new vaccine candidates are showing promising results.
The American group and its German partner have developed a monovalent vaccine based on the original Omicron variant, and another bivalent, based on both the original strain of the virus and on Omicron.
According to data from a phase 2 trial, a booster with these two types of vaccines elicits a higher immune response than with the currently marketed vaccine.
The American Moderna has for its part developed a bivalent booster vaccine, also based on the Wuhan strain and on the original Omicron variant.
It elicited high levels of infection-blocking antibodies against BA.4 and BA.5, according to the lab.
The groups say they can move on to producing such vaccines within three months.
How many doses will be needed each year?
For people “at risk”, ie 15 to 20 million French people, the health authorities have so far recommended two injections per year, or approximately one vaccination every six months.
"For some, the most fragile or immunocompromised, it even takes more," said Thursday on France Inter Alain Fischer, president of the advisory council for vaccine strategy.
For the others, a simple reminder (or 3rd dose) is enough today, according to him.
“You might think that if you enter a system with a seasonal upsurge in the virus – which is not the case now – an annual booster will suffice,” he said.
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