The SARS-CoV-2 virus is still making headlines. A new variant has been detected in twenty-three countries, including France. From its nickname BA.3.2, it stands out for its high number of mutations compared to the other variants on which the current vaccines against Covid-19 are calibrated.
According to a new study published in the weekly bulletin of the American Centers for Disease Control and Prevention (CDC), the genetic sequence of its Spike protein (the surface antigen targeted by vaccines) contains between seventy and seventy-five mutations. This is twice as many as the Omicron variant and its thirty mutations, in 2021.
BA.3.2 was first detected in November 2024 in South Africa, as Gizmodo recalls, but this new analysis shows that it is spreading throughout the world. Certainly, it only represents 0.55% of the 5,238 cases of Covid-19 analyzed by the CDC between last December and March. The concern, however, is more about quality than quantity. If the variants start to present so many genetic mutations, they could end up escaping our collective immunity built on vaccines and previous infections.
The laboratory experiments carried out for this new study show that the most recent vaccines are less effective against BA.3.2 than against six other better-known variants. “BA.3.2 represents a new lineage of SARS-CoV-2, genetically distinct from the JN.1 lineages that have been circulating in the United States since January 2024explain the authors. In our studies, this new variant effectively evades antibodies, probably due to mutations in the Spike protein. This illustrates the importance of constant monitoring of vaccine effectiveness.”
No increase in infections or deaths
This effectiveness nevertheless does not allow BA.3.2 to quickly replace the other variants in circulation. “In several European countries, it circulates in parallel with other JN.1 descendants with prevalences of approximately (10 to 40%)”specify the scientists. It is still present on five continents and, again according to the CDC, half of the fifty American states.
It is also in Europe that it is spreading the fastest. It constitutes 30% of new cases analyzed in Denmark, Germany and the Netherlands. German researchers have demonstrated in The Lancet that BA.3.2 escapes antibodies produced by the messenger RNA vaccines of 2025 and 2026 better than six other variants. The good news is that it has not caused an increase in contamination in these countries.
This new variant also does not seem to be accompanied by increased mortality. For now, the limited data available on BA.3.2 seem to indicate that it is only a problem for the elderly or those with comorbidities. In the latest CDC mortality bulletin, Harvard public health professor Daniel C. Grabowski advises “to avoid promiscuous environments such as overcrowded retirement homes which promote the spread of Covid-19”. And to favor “single rooms with good ventilation”.
Six years after the peak of the pandemic, this scientific activity reminds us that Covid-19 remains a major public health issue. This is particularly true in the United States, where the CDC counts more than ten million infections, including between 12,000 and 35,000 deaths linked to Covid-19 between October 2025 and March 2026. In France, in its bulletins over the same period, Public Health France mentions “syndromic indicators stable and at low levels”.
