90% of all influenza cases in Europe are caused by a new strain

The influenza wave in Europe this year is starting earlier than usual, with the spread of a new dominant viral variant already exerting significant pressure on healthcare systems in several countries and accounting for 90% of cases, WHO/Europe warns.

According to the organization, the influenza season has started approximately one month earlier compared to previous years. Currently, high or very high influenza activity is reported in at least 27 out of 38 countries in the European region that provide regular information. In six countries—Ireland, Kyrgyzstan, Montenegro, Serbia, Slovenia, and the United Kingdom—more than half of the patients tested with influenza-like symptoms have tested positive for the virus.

According to experts, this year’s season is characterized by the dominance of a new variant of the virus—A(H3N2), subclade K. Although there is currently no evidence that it leads to more severe disease progression, this specific strain already represents up to 90% of confirmed influenza cases in the region. “Even small genetic changes in the influenza virus can lead to serious pressure on healthcare systems, as the population has no built-up immunity,” states Dr. Hans Henri Kluge, WHO Regional Director for Europe.

The organization points out that while the vaccine does not guarantee complete protection against infection, initial data from the UK show that it significantly reduces the risk of severe complications associated with the A(H3N2) virus. Therefore, immunization remains a key preventive measure, especially for vulnerable groups—the elderly, patients with chronic diseases, pregnant women, and children.

Healthcare professionals are also among the priority groups for vaccination, as this protects both their own health and that of their patients, WHO/Europe emphasizes.

The number of cases is expected to continue rising until the peak of the season is reached, which will likely be in late December or early January.

Experts reiterate the importance of basic preventive measures—receiving the influenza vaccine, wearing masks when necessary, regular hand washing, and proper ventilation of indoor spaces. At the first signs of respiratory illness, it is recommended that individuals stay home to limit the spread of the infection.