Originally from India, a new sub-variant of Omicron, the BA.2.75, nicknamed Variant Centaure has been detected in France. It is closely monitored by the WHO. What symptoms do they cause? Is it more dangerous than the others? Mutations, virulence, vaccine… What we know to date.
[Mis à jour le 26 juillet 2022 à 15h05] Under the radar of the health authorities: a new mutation of the Covid. Appeared in India since May 2022, the new sub-variant of BA.2itself a subvariant of Omicron, was detected in France for the first time in July 2022: it is the subvariant BA.2.75also nicknamed “centaur variant” (or “centaurus” in English) unofficially. “It seems to become the dominant strain in India – the question is whether it will become the dominant strain all over the world“, indicates Antoine Flahault, director of the Institute of global health of the University of Geneva to AFP. closely monitored by health authorities, such as Public Health France or the World Health Organization (WHO). How many cases to date? Where in the world ? What specific symptoms would they cause? Would it be more dangerous than the other sub-variants? Knowledge to date.
Definition: what is the BA.2.75 sub-variant?
The BA.2.75 mutation or the V-22JUL-01 sublineage (nicknamed Centaur or Centaurus, unofficially, that is, the health authorities do not call it that) is a subvariant of BA.2, itself a subvariant of the Omicron variant of Covid. The BA.2 sub-variant was the majority in France until mid-June 2022, but has been gradually replaced by the BA.5 sub-variant, indicates Public Health France. “The BA.2 is a subvariant of Omicron, who is himself a “little cousin” of the Omicron variant“explained Jean-François Delfraissy, president of the Covid Scientific Council, at the microphone of France info in January 2022.
What is the origin of the BA.2.75 (centaur) variant?
In its risk analysis on the variants emerging from SARS-CoV-2 of July 6, 2022, Public Health France indicates that the majority of the sequences corresponding to the BA.2.75 subvariant come fromIndia. It was first reported in India in May and then spread to other countries: United States, United KingdomGermany, Canada, Japan, Netherlands, Australia, Nepal, Indonesia, New Zealand, Denmark, Italy, China, Luxembourg… And in France in July 2022.
How many cases of BA.2.75 are there in France?
As of July 22, 2022: 3 cases of BA.2.75 were detected in France, one in Martinique, one in Occitanie and one in the Grand Est, reports the worldwide tracking of the scientist Raj Rajnarayanan.
Is the centaur sub-variant more dangerous than the others?
“If it is still too early to know if this subvariant has stronger immune invasion properties and if it will have more severe effects clinically, we do not know yet. [Cette souche] would be followed closelyby the World Health Organization (WHO), says WHO chief scientist Soumya Swaminathan. According to Public Health France, the subvariant “BA.2.75 was spotted by the international community of bioinformaticians and virologists because it carries a significant number of additional mutations in the Spike protein (K147E, W152R, F157L, I210V, G257S, D339H, G446S, N460K, R493Q reversion…). Nowadays, no data indicating that BA.2.75 possesses different characteristics other BA.2 sub-lineages“. In other words, the centaur variant would not be more or less dangerous than the other BA.2 sub-lineages. Further research is ongoing.
What symptoms does the BA.2.75 variant cause?
This sub-variant would have the same characteristics as the BA.2 and more generally the Omicron variant. It would therefore cause the same symptoms, namely:
- A significant tiredness
- cough
- Fever
- Headaches
- Muscle pain or aches
- Sore throat
- Runny nose
- Digestive symptoms: nausea, vomiting, diarrhea…
- Sometimes a loss of taste and smell
Is the Covid vaccine effective against the BA.2.75 variant?
A priori yes, since the centaur variant has the same characteristics as the BA.2.
- HASafter two doses of vaccine, efficacy against symptomatic disease is 18% for BA.2
- After three doses efficacy against symptomatic disease is 74% for BA.2.
- Efficiency drops to almost 50% two and a half months after the 3rd dose for BA.2indicates a study of thebritish health agency published on February 25.
Sources: European Center for Disease Prevention and Control (ECDC) / Analysis of the risk of variants from Public Health France / SARS-CoV-2 variants of concern and variants under investigation in England, UK Health Security Agency, 22 July 2022.