The Expanded Program on Immunization (EPI), an initiative launched by the World Health Organization in 1974, stands as a global endeavor to ensure equitable access to life-saving vaccines for every child, regardless of their geographic location or socioeconomic status. Over the past five decades, the EPI has not only evolved but has also achieved remarkable milestones that have reshaped the landscape of global health. The 50th anniversary of EPI in 2024 provides a pivotal occasion to celebrate the program's achievements, highlight its impact on lives saved, and catalyze renewed efforts to strengthen routine immunization initiatives.