The International Day of Immunology is observed worldwide every April 29. Initiated by the International Union of Immunological Societies (IUIS) and the European Federation of Immunological Societies (EFIS), the day aims to highlight the significance of immunology in combating various diseases. The inaugural celebration took place in 2005, and since 2007, it has been recognized internationally. Activities on this day include conferences, symposiums, lectures, and seminars, often focusing on specific themes related to immunology, such as "Autoimmunity and Autoinflammation" in 2020 and "Immunology in the Time of COVID-19" in 2021. The achievements of immunology are crucial in treating immunological disorders, infections, and cancer, as well as in the development of vaccines that prevent infectious diseases. Every three years, IUIS and EFIS present awards for the best public relations campaigns related to the day, with a total prize fund of €6,000.