Influvac Tetra 2025/2026 Vaccine is an inactivated influenza vaccine designed for active immunization against influenza virus infection caused by the four influenza virus strains recommended for the 2025/2026 season. The vaccine contains purified, inactivated influenza virus antigens representing two influenza A subtypes and two influenza B lineages, formulated to provide broad protection against circulating influenza viruses. Administered via intramuscular injection, Influvac Tetra stimulates the immune system to produce strain-specific antibodies, thereby reducing the risk of influenza illness and its complications. It is indicated for use in individuals aged six months and older, including healthy adults, elderly populations, and those with chronic medical conditions who are at increased risk of severe influenza outcomes. The vaccine is contraindicated in individuals with a history of severe allergic reactions to any component of the vaccine, including egg proteins. Common adverse reactions are generally mild and transient, including injection site pain, erythema, and low-grade fever. Influvac Tetra should be administered annually prior to the onset of the influenza season to ensure optimal protection. Healthcare professionals should evaluate patient history and potential contraindications before vaccination to maximize safety and efficacy.