majority in France, symptoms, more contagious?

Over time, the COVVI-19 virus has mutated and new variants have emerged in the world and in France. One of them, named JN.1 or “Juno”, an omicron subvariant has been circulating in France since August 2023 and still seems to be the majority in August 2025.

Typical symptoms of variant JN1

Among the people infected with the JN.1 variant, 97% have symptoms. In its risk analysis, Public Health France informs that the most frequent symptoms are:

• A asthenia/fatigue,
• Headache (important headache)
• Feverish
• Cough
• A nasal flow / a blocked nose
• Sometimes a loss of taste (AGUEUSIE) / Loss of smell (anosmia)

Duration of symptoms

“The incubation time of the COVVI-19 has been considerably shortened since the start of the pandemic. It was on average 10 days with the original Wuhan strain, then 5 days with the Alpha and Delta variants, and 3 days with omicron” recalled the epidemiogist Antoine Flahaut on X in early 2024. According to him “It is likely that the incubation duration of the JN.1 variant is of the same order of magnitude as the other omicron subvariants: 3 days “. Symptoms last about a week, sometimes a little longer according to people.

What are the characteristics of JN.1?

All omicron’s sub-lines (including JN1) share the same characteristics: high transmissibility, immune exhaust and less severity. Compared to his parental ba. 2.86.1, Jn.1 presents three changes amino acids, only one in the SPIKE protein (L455S). In terms of severity, no worrying signal has been associated with JN.1 or its sub-lines.

More dangerous than others?

According to public health, in vitro data available suggest a larger immune exhaust of JN.1 compared to BA.2.86 But which could be partially compensated by a decrease in transmissibility. In other words, This variant would be “more resistant” antibodies but it would be less transmitted, no worrying signal in terms of severity was not associated with him, insists Public Health France. The health authorities, such as the FDA (Food and Drug Administration) and the EMA (European Medicines Agency), recommend adapting vaccines to JN.1 for vaccination campaigns 2024/2025 in order to better target the variants in circulation.