The Omicron variant of the coronavirus responsible for COVID-19 appears to spread more than the Delta variant, causing less severe symptoms and making vaccines less effective, the World Health Organization (WHO) said on Sunday, which points out 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 does seem to spread faster than the Delta variant, which for the time being is still responsible for most of the infections in the world. 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 know at this time – for lack of sufficient data – whether this high rate of spread in populations with high immunity is due to Omicron “evading immunity, benefiting from inherent higher transmissibility, or ‘it is a combination of the two’.
The organization predicts, however, that “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 “mild to moderate” as well in southern Africa, where it was detected, than in Europe.
As for vaccines against COVID-19, the limited data available as well as the genetic profile of Omicron suggest “a decrease in effectiveness” with regard to protection against “infection and transmission”.
For their part, the Pfizer and BioNTech laboratories – which developed the Cominarty vaccine, one of the most effective against COVID so far – assured at the end of last week that it was “still effective” after three doses against Omicron.
The majority of countries that can afford it are already encouraging people to get a booster dose. This is particularly the case in Europe, faced with a new wave of infections, caused by Delta, due to the premature abandonment of health restrictions, but also to sometimes insufficient vaccination rates.