The flu vaccine is 70-90 percent effective in healthy children and adults up to 65 years of age[1][2][3]. Effectiveness declines in the elderly over 65, but vaccination reduces hospitalizations due to pneumonia and influenza by up to 60 percent and deaths by up to 68 percent[1]. The World Health Organization recommends vaccinating at least 75 percent of older people and risk groups[1][3]. Vaccine effectiveness declines by approximately 6-11 percent per month[1][2][4]. Even if the vaccine strains do not agree with the circulating virus, the vaccine reduces the symptoms of the disease by 20 percent, which is of great importance for risk groups[1][2]. Vaccination is recommended every year between October and December[5]. For the 2025/2026 season, insurance companies fully cover the vaccines VAXIGRIP, INFLUVAC, INFLUVAC TETRA and VAXIGRIP TETRA[6][8]. Influenza vaccines are considered safe[7].