The new vaccination campaign against Covid began on Monday: a vaccine booster which allows us to “restore memory to our immunity in order to defend us against serious forms” of the disease.
“You should expect to have a booster vaccination probably every year”, said Monday October 2 on franceinfo Professor Bruno Mégarbane, head of the medical and toxicological intensive care unit at Lariboisière hospital in Paris (AP-HP), while a new vaccination campaign against Covid-19 began on Monday. . Intended for populations most at risk, it was initially scheduled to begin on October 17. The virus “regularly adapts to the collective immunity with which it must face”, explains Bruno Mégarbane. The vaccination booster therefore makes it possible to “restore memory to our immunity in order to defend ourselves against serious forms” of the disease.
>> Covid-19: six questions about the new vaccination campaign which begins on October 2
franceinfo: What vaccine is being delivered for this new vaccination campaign?
Bruno Megarbane: It is a new version of the Pfizer vaccine in particular, which is a vaccine which is oriented with a variant which is very close to the omicron variants which are currently circulating. It would make it possible to strengthen the immunity that we have acquired following previous infections or basic vaccination which used a messenger RNA corresponding to the historical virus which had come from China, a virus which is no longer circulating today. today among men.
Will this vaccine evolve every year like the one against the flu?
SARs-CoV-2 is a virus which regularly adapts to the collective immunity it must face, and which forms in humans following successive infections and possible vaccinations. It must try to modify its surface, in particular its Spike protein, to avoid being recognized and immediately neutralized by the immune system in order to transmit and reproduce. In fact, it manages to escape immune surveillance. We must therefore teach the immune system, very regularly, to recognize it by adapting the vaccine to the latest sub-variant circulating. We should expect to have a booster vaccination probably every year, a bit like the flu, to restore memory to our immunity in order to defend us against serious forms of the disease.
Are vaccines made in the midst of an epidemic no longer effective?
They are effective in protecting against deadly forms of the disease. During the first waves of Covid-19, we had an extremely high mortality rate, with extremely serious pneumonic forms in people who had very few comorbidities. But the population was naive. And so the initial vaccination that was undertaken made it possible, at an extremely high speed, to acquire this collective immunity which forced SARs-CoV-2 to evolve into a slightly less virulent omicron form. And today, it’s a balance between this human immunity and this virus, the two obviously trying to coexist without too much damage.