Annual Influenza Epidemics Remain Unpredictable – Early Peak Possible This Winter
Norway is bracing for another influenza season, and experts warn the peak could arrive as early as Christmas. While influenza epidemics occur every winter, their severity and timing remain uncertain. The commentary from The Journal of the Norwegian Medical Association is authored by Professor II at the Pandemic Centre, Preben Aavitsland (FHI), who emphasizes the importance of monitoring developments closely and maintaining preparedness.
By: Gøril Vikøren Nøkleby
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Each year, hundreds of thousands of Norwegians contract influenza, straining healthcare services and disrupting schools and workplaces. Typically, epidemics begin in December, peak in February, and taper off by late March. In a normal season, up to 20% of the population may be infected, though most experience mild or no symptoms.
Last winter saw over 100,000 influenza-related consultations in Norway, more than 10,000 hospital-confirmed cases, nearly 300 intensive care admissions, and around 400 deaths. Additional fatalities from complications such as pneumonia and heart attacks are also linked to influenza.
This year’s outlook is particularly unpredictable. Early data suggest the epidemic may start sooner than usual, driven by a dominant A(H3N2) variant that differs significantly from previous strains and current vaccines. This mismatch could mean lower immunity and a higher risk of severe illness, especially among young children and older adults. Reports from England indicate reduced vaccine effectiveness in seniors, increasing hospitalization risks.
However, experiences from Hong Kong show the epidemic with this strain is already ending there, with a normal disease burden. For now, experts urge vigilance as the season unfolds.