This year marks the 50th anniversary of the introduction of the World Health Organization (WHO) EPI, originally known as the Expanded Programme on Immunization. On May 23, 1974, during the 27th World Health Assembly (WHA) in Geneva, Switzerland, WHO member states advocated for the development of immunization and surveillance programs targeting diphtheria, pertussis, tetanus, measles, poliomyelitis, tuberculosis, and smallpox. At that time, despite the availability of vaccines, these 7 disease continued to be major causes of mortality among children. At a special event of the WHA on May 28 this year, WHO Director-General Dr. Tedros highlighted that immunizations have enabled 40% of children to celebrate their first birthday who would not otherwise been able to. He noted that vaccines have prevented approximately 154 million deaths, with the most significant impacts coming from vaccines against measles, tetanus, pertussis, and tuberculosis. This statement was part of a study examining the contribution of vaccination to improved survival and health over 50 years of the EPI [1]. Dr. Young-mee Ji, Commissioner of the Korea Disease Control and Prevention Agency (KDCA), emphasized in this event that the EPI has significantly contributed not only to immunization but also to Universal Health Coverage in many developing countries. She highlighted the critical role of WHOs regional and country offices in this success, stating that the roles of country offices should be further expanded. While personally participating in measles vaccination campaigns (2007, 2010, 2014) in Philippine, Dr. Ji underscored that the EPI has made substantial contributions to health system strengthening. Reflecting on the history of the EPI, 1974 stands out as a pivotal year in public health. At that time, despite the availability of vaccines, many children remained unvaccinated. Former WHO Director General Dr. Halfan Mahler urged member states to intensify efforts at all levels to address this issue, which led to the establishment of the EPI. Now, 50 years later, the initiative is known as the Essential Programme on Immunization. It recommends 13 vaccines immunization efforts have saved at least 154 million lives over the past 50 years.