Influenza season 2026/2027 shows early activity in Southeast Europe

The 2026/2027 influenza season is showing early activity across Southeast Europe, marked by vaccine supply delays in Slovenia and rising case numbers in Croatia and Bosnia and Herzegovina.

In Slovenia, the National Institute of Public Health (NIJZ) has announced that seasonal flu vaccinations will be delayed until November 2, 2026, due to supply issues. This delay is reportedly a trend affecting several European countries. Health officials noted that limited initial quantities will prioritize high-risk groups.

Croatia has reported an unusually early appearance of the flu, with cases noted as early as August. As of early October, dozens of cases have been confirmed, with the highest incidence rates observed among preschool children. Vaccination in Croatia is expected to begin in early November following the arrival of 420,000 doses.

In the Federation of Bosnia and Herzegovina, enhanced surveillance for respiratory viruses has commenced. During the first week of monitoring, 163 cases of influenza-like illness were reported in primary healthcare settings, though laboratory tests for influenza, SARS-CoV-2, and RSV were negative in initial samples.