Flu Season Begins Early Across Greece and U.S.
Rising infection rates and new genetic variants in influenza strains signal a potentially unpredictable viral season.
Updated on Oct. 30, 2026 in Allergies
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Greece has entered its flu season 15 days earlier than usual following a surge in positive tests. Similarly, influenza activity is rising ahead of expectations in the United States due to an emerging genetic variant.
Why it matters
The earlier onset of the virus combined with genetic changes creates an unpredictable season for public health. Experts are particularly concerned about the risk of severe illness in younger populations who may have limited prior exposure to circulating H1N1 variants.
Positive influenza tests in Greece surpassed 10% during the week of October 5-11, while hospital admissions jumped from 27 to 52. Meanwhile, EU and EEA vaccination coverage remains at 47%, trailing the 75% goal for older adults.
The details
Most influenza samples tested in the United States currently belong to the H1N1 subtype, which features a specific genetic change known as G155E in the hemagglutinin protein. Environmental factors, including cooler weather and increased time spent in crowded indoor settings, continue to influence the rate of viral transmission.
Timeline
October 5-11, 2026: Positive flu tests in Greece exceeded 10%.
Late October 2026: Greece officially entered its flu season.
2024-2025 season: EU and EEA vaccination coverage among older adults reached 47%.
November 2026: The next three weeks are critical for determining future flu trends.
Health Landscape
This reporting tracks how the G155E hemagglutinin genetic variant monitoring program is identifying virus mutations that might evade existing immune defenses. Such genetic surveillance is essential to understanding why certain flu seasons diverge from historical norms.
The earlier arrival of flu season highlights the importance of timely vaccination, especially for vulnerable populations who may lack recent exposure to H1N1 variants. Individuals should monitor local health advisories as experts watch whether this early spike continues to spread internationally.
The takeaway
Maintaining updated vaccination status remains the most effective defense against evolving influenza strains. Public health officials advise that crowded indoor environments significantly increase transmission risk as the season progresses.
Further reading
Learn more about seasonal virus trends in the Allergies section.
Source note: This article includes information reported by Tovima.
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