“World Immunization Week – celebrated every year in the last week of April – aims to promote the use of vaccines to protect people of all ages against disease. Immunization saves millions of lives every year and is widely recognized as one of the world’s most successful health interventions. Yet, there are still nearly 20 million children in the world today who are not getting the vaccines they need, and many miss out on vital vaccines during adolescence, adulthood and into old age”World Health Organization
2022’s theme has not been announced yet. More information on World Immunization Week 2021 here.