World Immunization Week is a health campaign coordinated by the World Health Organisation (WHO) and celebrated in the last week of April, every year. It aims to promote the use of vaccines to protect people of all ages against disease. Immunization saves millions of lives and is widely recognized as one of the world’s most successful and cost-effective health interventions. Yet, there are still nearly 20 million unvaccinated and under-vaccinated children in the world today. World Immunisation week - April 24 - 30, 2026 Under the banner of ‘For every generation, vaccines work’, WHO is working with partners to support countries to get back on track to ensure more people are protected from preventable diseases. Vaccines have long been one of the most powerful tools in public health. Over the past 50 years, vaccines have saved more than 150 million lives – not by accident, but because ordinary people made the decision to protect themselves, their children and their communities from diseases like measles, diphtheria, pertussis, polio, and rotavirus. Today, newer vaccines against malaria, HPV, cholera, dengue, meningitis, RSV, Ebola, and mpox are saving even more lives, and helping people at every stage of life live longer and healthier thanks to scientific advancements. Under the theme, “For every generation, vaccines work”, World Immunization Week will promote how vaccines have safely protected people, families, and communities for generations – and continue to safeguard our future. Key facts Vaccines have long been one of the most powerful tools in public health. Vaccines protect people at every stage of life. Your decision makes a difference. Get vaccinated. Source : World Health Organisation Related resources Campaign materials