cases in France in June, symptoms, more dangerous?

Over time, the Covid-19 virus mutates and new variants circulate around the world and in France. One of the last, named JN.1 or “Juno” is a sublineage of BA.2.86 (nicknamed the Pirola variant), itself sous-variant d’Omicron. First identified in August 2023 and majority since November 2024, JN.1 still is this summer “in France and worldwide” specifies Public Health France in its latest bulletin of June 26, representing 92% of contaminations in France as of June 3. Recently, this variant has also mutated and given several sub-lineages: the most detected sub-lineage is KP.2 for which circulation tends to decrease (representing 21% of contaminations to date) and KP.3 (in pink on the graph) which is increasing ( also representing 21% of contaminations).

Typical symptoms of the JN1 variant

Among those infected with the JN.1 variant, 97% show symptoms. In its risk analysis, Santé Publique France informs that the most common symptoms are:

• Asthenia/fatigue,
• Headaches (severe headaches)
• Fever
• Cough
• A runny nose / A blocked nose
• Sometimes, loss of taste (ageusia) / loss of smell (anosmia)

In 2024, the NHS (British Health Agency) has reported a new symptom of this variant: diarrhea. In France also. “Since the first variants, we have observed that the coronavirus causes diarrhea. This symptom seems more frequent with the new variant, but it is not new.“, insists Antoine Flahault, epidemiologist and professor at the Faculty of Medicine of the University of Geneva, who reassures us that “This will not lead to more serious forms” by Covid.

Duration of symptoms

Symptoms usually develop on average 5 to 7 days after contaminationbut this period can extend from 2 to 14 days in some cases. Symptoms usually disappear within 2 to 3 weeks.

How many cases in France in 2024?

LFrance is one of the countries reporting the most cases from JN.1: since the beginning of February 2024 and as of June 3, it represented 92% interpretable sequences. The JN.1 variant is the one that circulates the most in France. Among the classified JN.1 sublineages, the detection of KP.2 tends to decrease, it represented respectively 27%, 18% and 21% of the interpretable sequences of the Flash surveys of 21/05, 27/05 and 03/06. The sublineage KP.3 is increasing, it represented 9%, 22% and 21% of the interpretable sequences of the Flash surveys of 21/05, 27/05 and 03/06, respectively.

What are the characteristics of JN.1?

Compared to its parental subline BA.2.86.1, JN.1 has three mutations of amino acids including only one in the Spike protein (L455S). Despite this, no worrying signal in terms of severity has been associated with it, reports Public Health France.

More dangerous than the others?

According to Public Health France, the available in vitro data suggest greater immune escape of JN.1 compared to BA.2.86 but which could be partially compensated by a reduction in transmissibility. In other words, this variant would be “more resistant” to antibodies but it would be less transmissible.