Still 6 million unvaccinated in France! The government is trying at all costs to encourage vaccination. The booster dose can now be taken as early as 4 months after the last injection. Against the highly contagious Omicron, will this be enough?
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The variant Omicron spreads at lightning speed all over the planet. He should become dominant in the coming weeks. Scientists are mobilizing to try to better understand it in order to better fight it. New data on the effectiveness of vaccines have just been published. Even people who have received three doses of the vaccine may not be fully protected against this extremely new variant. contagious. Even more worrying, the protection conferred by the booster dose would only be effective for a few weeks …
The 3e dose, or booster dose, would not be enough
A study not yet published suggests that the Omicron variant would be in part resistant to patient antibodies convalescents but also to antibody of patients on the complete vaccination schedule (two doses of an mRNA vaccine + booster). This information is confirmed by the CEO of BioNTech, who designed the vaccine with Pfizer: “ Even triples vaccinated are likely to transmit Covid-19. There will be a loss of efficiency against Omicron over time … We are far from the 95% efficiency that we had obtained against the virus initial », He adds.
After the second dose, vaccine efficacy would only be 20%. It would rise to 70% after the third dose … for a while. Just three months after the 3e dose, the efficacy would fall below 25%. Despite these maddening data, it would seem, however, that protection against severe forms of the disease remains.
We are far from the 95% effectiveness that we obtained against the initial virus
Why does the variant escape vaccines?
One of the peculiarities of the Omicron variant is its impressive number of mutations on the Spike protein. The Spike protein is an essential protein in the way vaccines and drug therapies work. monoclonal antibodies currently available.
In the case of the vaccine, the mRNA contains the blueprint for making the Spike protein. When injecting the vaccine, our body will manufacture it and expose it to the surface of our cells. In contact with the Spike protein, the immune cells will produce antibodies against the virus. Our body will already be armed if it encounters the virus … unless the Spike protein produced with the vaccine differs too much from the Spike protein of the variants in circulation. Rather than being vaccinated every 3 months, the vaccine must be adapted to the variants. This is what is done each year with the vaccine against influenza.
Pfizer-BioNTech is in the process of designing a suitable vaccine the large number of mutations of the Spike protein of the Omicron variant. This should be available in March. In the meantime, barrier gestures remain relevant during this holiday season, even for triples vaccinated.
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