Before him, no SARS-CoV-2 variant had spread so quickly.
Less than a month after being identified in South Africa, Omicron now has a majority in the UK, US, and should soon be in France and other European countries.
Each time, it is at the origin of a very rapid increase in new cases of Covid, without it being possible yet to anticipate what the impact will be on the hospital.
The Omicron variant has no less than 32 mutations on its Spike protein, the most sensitive area of the virus.
Some of them give it what is called an 'immune escape', which means it can make vaccines less effective, as we explain to you in this video.
VIDEO.
Why does the Omicron variant reduce the effectiveness of vaccines?
According to a study by the largest private health insurance organization in South Africa, two doses of Pfizer vaccine would be 70% effective against hospitalization in case of infection with Omicron, against 93% at the time from Delta. What about the booster dose? According to data from the British health agency, a third dose in a 100% Pfizer vaccine schedule would raise the effectiveness against symptomatic forms to 70%… but it would drop to 45% ten weeks later. The risk of reinfection appears to be greater with Omicron, while monoclonal antibodies appear to be very ineffective.
The good news that appears in this seemingly grim painting is that Omicron looks less virulent.
Several studies agree on the fact that the risk of hospitalization in the event of contamination seems to be reduced compared to an infection by Delta.