the Omicron variant seems to diffuse faster and make vaccines less effective, says WHO

We are starting to learn more about Omicron. This variant of the coronavirus responsible for Covid-19 seems to spread more than the Delta variant, cause less severe symptoms and make vaccines less effective, the World Health Organization announced on Sunday, December 12. WHO emphasizes, however, that the data remains very fragmented.

Omicron is now present in 63 countries, said the organization in a technical update, which confirms the statements of its officials in recent days. According to the WHO, Omicron seems to be spreading faster than the Delta variant, which is still responsible for most of the infections in the world for the time being. This faster diffusion is seen not only in South Africa, where Delta was less prevalent, but also in the United Kingdom, where this variant dominates.

WHO does not yet know – for lack of sufficient data – whether this high rate of dissemination in populations with high immunity is due to the fact that Omicron “evades immunity, benefits from inherent higher transmissibility or if it is a combination of the two”. The organization predicts, however, that it “Omicron is likely to outperform Delta in places where there is community transmission”.

The data are not yet sufficient either to establish the degree of severity of the disease caused by Omicron, although for the moment the symptoms appear. “light to moderate” both in southern Africa, where it was detected, and in Europe.

As for the anti-Covid vaccines, the little data available as well as the genetic profile of Omicron suggest “a decrease in the effectiveness” with regard to the protection against “the infection and the transmission”. For their part, the Pfizer and BioNTech laboratories assured at the end of last week that it was “always effective” after three doses against Omicron.