Vaccination: A Legacy of Success and Persistent Challenges, 50 Years Since the Launch of the Expanded Programme on Immunization

Fifty years have passed since the Expanded Programme on Immunization (EPI) was established by the World Health Assembly in May 1974, revolutionizing global vaccination coverage and significantly reducing the disease, social, and economic burden of vaccine-preventable diseases included in the program. This publication provides a comprehensive overview of the global impact of vaccines, covering their history—from variolation to modern and future vaccine platforms—as well as the creation of key organizations such as the Pan American Health Organization (PAHO) and the World Health Organization (WHO). It also highlights the contributions of both humanitarian and commercial entities that have played a crucial role in achieving worldwide vaccination reach. While celebrating these achievements, this work also underscores the present and future challenges in ensuring equitable vaccine access across the globe. Additionally, it emphasizes the urgent need for vaccines against numerous diseases that remain without immunization solutions. Without a doubt, vaccination stands as the most impactful public health intervention of our time.