Childhood vaccination is among the most successful and cost-effective public health interventions in human history. Immunization programs have substantially reduced morbidity, mortality, and disability associated with vaccine-preventable diseases such as measles, polio, diphtheria, pertussis, tetanus, and hepatitis B. Despite remarkable progress, significant disparities in pediatric vaccination coverage persist globally due to socioeconomic inequalities, healthcare access barriers, vaccine hesitancy, misinformation, conflict, and disruptions in health systems. Recent global estimates indicate that millions of children remain under-vaccinated or completely unvaccinated, increasing the risk of outbreaks and reversing public health gains. This study reviews pediatric vaccination coverage, determinants of vaccine uptake, public health impacts, challenges affecting immunization programs, and strategies for improving vaccine coverage. Through a comprehensive review of epidemiological studies, international reports, and immunization policies, the study highlights the importance of achieving high vaccination coverage to ensure herd immunity and disease control. Findings indicate that strengthening immunization systems, combating misinformation, improving healthcare access, and adopting data-driven public health approaches are essential for achieving global immunization goals. Childhood immunization prevents an estimated 4.4 million deaths annually and remains a cornerstone of global child health.