This clinical trial is focused on understanding how the body responds to different types of flu vaccines. The study involves two types of influenza vaccines: Fluenz Tetra, which is a nasal spray, and Vaxigrip Tetra, which is given as an injection. Both vaccines are designed to protect against the flu, a common viral infection that affects the respiratory system.
The purpose of the study is to compare the immune response, specifically the production of antibodies, between the two methods of vaccination. Antibodies are proteins made by the immune system to help fight infections. The study will look at how these antibodies develop in the nose and blood after receiving either the nasal spray or the injection. Participants will receive one of the vaccines and will have samples taken from their nose and blood at various times to measure the levels and types of antibodies produced.
The study will take place over several weeks, with participants being monitored at different intervals to track changes in their immune response. This includes measuring specific proteins and cells in the body that are involved in fighting infections. The goal is to better understand how each vaccine works and to gather information that could help improve flu vaccination strategies in the future.



The Netherlands