Covid-19: what we know about the two new Omicron sub-variants discovered in South Africa – franceinfo

When will the Covid-19 pandemic end? The World Health Organization (WHO) estimated on May 4 that two subvariants of Omicron, identified in South Africa, were behind the fifth wave hitting the country, the most affected on the African continent. by disease. The momentum is strong: the number of new recorded cases of Covid-19 in South Africa has increased from some 3,500 cases on May 3 to around 7,500 a week later, an increase of more than 100%. Franceinfo summarizes what we know about these two sub-variants, baptized BA.4 and BA.5, which carry this new wave. They were discovered at the end of 2021 “South African scientists, who identified Omicron late last year, have now reported two other Omicron sub-variants, BA.4 and BA. 5 as being behind a spike in cases in South Africa,” WHO Director-General Tedros Adhanom Ghebreyesus said in early May. They could have been discovered “because South Africa is still carrying out the genetic sequencing [du virus] that other countries have stopped doing, the WHO leader stressed. In many countries we cannot see how the virus mutates. We don’t know what lies ahead.” The Omicron variant was first detected in South Africa in November 2021. So far, it had “four lineages named B.1.1.529 [le premier à avoir été appelé Omicron], BA.1, BA.2 and BA.3”, reported the WHO in January. Around the end of 2021 and the beginning of 2022, the BA.2 variant was discovered in several countries, including France.They are more contagious than the other BA.4 and BA.5 sub-variants “seem to be more transmissible than the previous” Omicron sub-variants, epidemiologist Antoine Flahault told France 24. Their Spike protein, which allows the virus to enter our cells, carries two mutations. One called L452R increases its transmissibility, causing it to be about 20% more contagious than the BA.2 subvariant. It is not unknown since it is present in the particularly contagious Delta variant, which raged in the summer of 2021. The other mutation, called F486, “is associated with a reduction in the neutralization of antibodies”, according to Antoine Flahault. a potential decrease in the effectiveness of the vaccine against these two sub-variants, he reports to La Dépêche. nche, the dangerousness of these two sub-variants is still unclear. “It is too early to know whether these new subvariants can cause more severe forms of the disease than other Omicron subvariants,” the WHO boss said. “So far, the South African authorities have not observed a significant increase in the severity of these new variants”, remarks Antoine Flahault. They have already been detected in France The BA.4 and BA.5 subvariants are in the majority in South Africa, as shown by epidemiologist Tulio de Oliveira, director of the Center for Innovation and Response to Epidemics, an institute South African research. South Africa had multiple waves of infections, the first dominated by multiple lineages (> 50 614G lineages), the second by Beta, them Delta, Omicron BA.1, BA.2 and Omicron BA.4 and BA.5. pic.twitter.com/19n8PVvXIJ — Tulio de Oliveira (@Tuliodna) May 8, 2022 In France, the BA.2 subvariant of Omicron is still very largely dominant, according to Public Health France (99% of the sequences of the last investigation). But BA.4 and BA.5 have already been detected in France. If they are still very much in the minority, they are scrutinized and are the subject of “reinforced surveillance”, writes Public Health France in its epidemiological bulletin of May 5. “As of May 2, 2022, two cases of BA.4 and six cases of BA.5 have been confirmed in France and are under investigation”, specifies the health agency. For Antoine Flahault, vigilance is required with regard to previous episodes. “Several waves of contamination, which occurred in the past in South Africa, preceded those which occurred a little later in Western Europe, recalls the epidemiologist in the columns of La Dépêche. This could be the case again with BA.4 and BA.5, which could arrive in Europe before mid-June.” “This wave of contamination will not necessarily be associated with a significant increase in hospitalizations and deaths, but we must follow current South African developments very closely and prepare,” insists the specialist to France 24. Tulio de Oliveira, the situation in South Africa can “guide the whole world” towards the future of the pandemic.