In 1974, the World Health Organization (WHO) established the Expanded Programme on Immunization to ensure that all children have access to routinely recommended vaccines. Despite improvement in global coverage with the third dose of diphtheria-tetanus-pertussis (DTP) vaccine (DTP3), from 5% in 1974 to 83% in 2011, almost one fifth of the world's children still had not received their third dose of the DTP series during their first year of life. In May 2012, the World Health Assembly endorsed the Global Vaccine Action Plan (GVAP) to guide the Decade of Vaccines' vision to extend benefits of immunization to all persons. GVAP's key indicators include achieving and sustaining 90% national DTP3 coverage and ≥80% DTP3 coverage in every district by 2015. During 2012, as in the 2 preceding years, an estimated 83% of infants worldwide received 3 doses of DTP vaccine; however, coverage varied among the WHO regions. Among 194 WHO member states, 131 (68%) achieved ≥90% DTP3 national coverage, and 59 (30%) achieved ≥80% DTP3 coverage in every district. However, 22.6 million children did not receive 3 DTP doses, a key indicator of immunization program performance. Strengthening national immunization systems, especially in countries with the greatest number of undervaccinated children, should be a global priority to reduce morbidity and mortality from vaccine-preventable diseases.