For several weeks, health authorities in multiple countries have been on alert due to the early and rapid increase in flu cases caused by the H3N2 variant of the influenza A virus. This strain currently dominates global circulation and has already triggered spikes in hospitalizations across Europe, North America, and Asia. The variant, known as the K subclade, has shown a greater transmission capacity than in previous years, contributing to a much more active start to winter.
The mutations present in this variant have partially reduced the effectiveness of the standard flu vaccine, although it still provides important protection against severe forms of the illness and hospitalizations. For this reason, experts emphasize the importance of getting vaccinated, maintaining good hand hygiene, ventilating closed spaces, and staying home at the first sign of symptoms.
Why is this flu season more concerning than previous ones?
This is due to a combination of factors: a more transmissible variant, lower population immunity to H3N2, and an early onset of circulation have created an environment where the flu can spread more aggressively and affect more severely those who are unvaccinated or vulnerable.
