The Pasteur Institute of Iran, in collaboration with the Iranian Society of Immunology and Allergy, celebrated World Immunology Day on April 29^th, 2025, with a one-day symposium at its Tehran campus. The event was attended by the institute's Director-General, along with senior immunology professors, researchers, and students. Key lectures focused on the history and development of the Immunology Department at the Pasteur Institute of Iran, the philosophy of science in immunology, advances in brain immunity, and the influence of emerging technologies on future immunological research. The event underscored the institute’s commitment to advancing immunology research and fostering collaboration within the scientific community.