New Flu Subclade Raises Concerns Ahead of 2025-2026 Season, But No Imminent Threat
Paris, France – Health officials are closely monitoring a newly circulating H3N2 influenza subclade as the Southern Hemisphere enters its winter season, but experts emphasize its premature to anticipate a dramatically worse flu season than previously experienced. While the 2024-2025 season in France was particularly challenging – starting early, lasting twelve weeks, and linked to an estimated 17,000 excess deaths from all causes – current data doesn’t suggest this new variant causes more severe illness than other H3N2 strains. However,the confluence of factors,including potential for increased severity in vulnerable populations and existing gaps in vaccination coverage,warrants continued vigilance.
The emergence of this subclade comes after a grueling 2024-2025 flu season that significantly impacted France, particularly the elderly and those wiht underlying health conditions. The upcoming 2025-2026 season is therefore under heightened scrutiny, as public health officials assess the potential impact of the new variant. While an “imminent threat” hasn’t been declared,experts stress the importance of vaccination – currently at 46.5% coverage among at-risk individuals in France, reaching 53.7% for those 65 and over – as the primary defense against severe illness and hospitalization.
According to Public Health France, the 2024-2025 flu season began earlier than usual and extended for twelve weeks, exceeding the average duration. The season was accompanied by approximately 17,000 excess deaths attributed to all causes. British experts are particularly focused on the combination of this new subclade with other contributing factors.
In France, caution remains advised, but current evidence doesn’t support the conclusion of a “catastrophic” season. The flu, especially when dominated by H3N2, is known to be particularly perilous for the elderly and those with compromised immune systems. Vaccination, even with its limitations, remains the most effective strategy to prevent severe outcomes.
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In France, influenza vaccination coverage for the 2024-2025 season is estimated at 46.5% among all individuals at risk of severe influenza. This rate increases to 53.7% among those aged 65 and over.
