Another newcomer to the Omicron family. On August 17, “WHO placed under surveillance a new variant carrier of many mutations, the BA.2.86 variant, which once again underlines the need for all countries to continue surveillance activities”, declared the next day the director general of the organization, Tedros Adhanom Ghebreyesus.
Why is this last identified sub-variant, and since baptized Pirola, in the sights of the WHO? In which countries has it been detected? Should we be worried about seeing it arrive in France? And could it cause an epidemic rebound in Europe? 20 minutes takes stock of what we know.
Many mutations but little information
If Pirola is already attracting attention, it is because this new variant has “a significant number of mutations which could help the virus to escape the immune response”, explains to the Italian press agency ANSA Professor Massimo Ciccozzi, director of the Molecular Statistics and Epidemiology Unit of the Campus Bio-Medico in Rome, and co-author of an article on the Pirola variant published in Journal of Medical Virology. Among the thirty or so mutations observed, “two in particular must be monitored because they could make it more transmissible”.
And if the scientists indicate that they still lack information on Pirola, “the increase in mutations is a significant change, similar to the jump that occurred between the Delta and Omicron variants”, estimates Roger Paredes, head of the infectious diseases department. of the Germans Trias Hospital in Pujol, Catalonia, in an interview with the media El Periodico. In November 2021, Omicron, discovered in South Africa, had supplanted the Delta variant internationally in a few weeks.
On the other hand, Pirola does not seem to be associated with any particular symptoms to date. “According to the little data available, they resemble those of the flu, with a fever of 38°C for a few days, an intense cold and headaches, detailed Professor Ciccozzi. As with some of the later variants, it is no longer characterized by asymptomatic cases.”
Identified in six countries
It was on July 24 that this new variant was discovered in Denmark. It has since been detected in South Africa, the United States, Israel and the United Kingdom. As well as in Spain, in Catalonia, a border region of France. But he has not yet been identified in France. “What is particularly interesting is that, unlike other variants, there is no epidemiological link between the different cases, observes Professor Ciccozzi. That is to say, they do not seem to be linked to each other”.
For the time being, “nine sequencings of BA.2.86 have been reported in five countries: three in Europe, one in Africa and one on the American continent”, indicates the WHO in its epidemiological bulletin of August 23.
Epidemiological effects still unknown
While under the effect of Eris, another sub-variant of Omicron, contaminations are on the rise again, could Pirola cause an epidemic rebound of Covid-19 in Europe and in the world? “The potential impact of BA.2.86 mutations is not known at this time”, replied the WHO, which reiterates its call for “better surveillance, sequencing and notification of cases of Covid-19, like this virus. continues to circulate and evolve”. Although the coronavirus “is no longer a global health emergency, it remains a threat to global health”, insisted Tedros Adhanom Ghebreyesus.
The data is still patchy, but some scientists are already sketching out possible trajectories. Pirola “has all the hallmarks of something that could take off, however, our immune landscape is now complex, so it’s too early to say it will, ahead of X [Twitter] Kristian G. Andersen, Danish researcher in infectious diseases and genomics. But I think it is possible”.
For Professor François Balloux, professor of computational biology at University College London, “BA.2.86 is the most striking Sars-CoV-2 strain the world has witnessed since the emergence of Omicron”, reports THE british medical journal. But, reassures Professor Balloux, “even in the worst case, where BA.2.86 would cause a new wave of cases, we do not expect to witness comparable levels of severe forms and deaths as we have seen more early in the pandemic when the Alpha, Delta, or other Omicron subvariants have spread.”