Les anticorps du vaccin Pfizer peuvent être jusqu'à 40 fois moins efficaces contre Omicron </p><div> <p><b>Par Tom Clarke, rédacteur scientifique et technologique</b>
Antibodies from the Pfizer vaccine may be up to 40 times less effective against Omicron than the original COVID strain, the first lab tests on the new variant have shown in South Africa.
But while its ability to evade vaccine antibodies is important, it is not complete, and that’s good news, says Professor Alex Sigal, a virologist at the Africa Health Research Institute, who led the research.
The study found that antibodies from people who had been vaccinated as well as naturally infected with COVID were significantly more effective against Omicron – suggesting that boosters may provide a significant benefit.
Its ability to escape the vaccine was between five and 10 times better than the beta variant, which was also first reported in South Africa and previously had the best ability to escape the vaccine.
Professor Sigal, who leads the team doing the testing, believes it is likely that Omicron has both immune evasion and a transmission advantage over other variants.
The study is very small, having looked at live Omicron virus grown in the lab and tested on blood samples from only 12 vaccinated people.
As such, it cannot tell us much about the effectiveness of vaccines against the prevention of infection or subsequent transmission of Omicron in the real world.