Influenza is one of the most significant respiratory infections affecting adults worldwide, and it causes widespread morbidity and mortality every year: healthy individuals often experience mild-to-moderate symptoms, while adults with underlying chronic conditions, compromised immune systems, and those over 65 years of age are at a considerably higher risk of severe complications and death. In Europe, seasonal influenza leads to increased healthcare utilization, lost productivity, and an overall burden on public health services every year. Influenza viruses A and B, chiefly responsible for seasonal human infection, can undergo minor genetic changes (antigenic drifts) that lead to partial evasion of previously developed immunity, contributing to seasonal epidemics. Moreover, influenza A viruses can undergo an antigenic shift, leading to novel viruses with pandemic potential. All these factors highlight the importance of maintaining continuous surveillance, annual updates of vaccine compositions, and robust immunization efforts.