The primary purpose of vaccination in public health is to stimulate the immune system to recognize and fight specific infectious agents, thereby preventing disease. Vaccines work by introducing weakened or inactive parts of pathogens, allowing the immune system to develop a response without causing illness. This strategy is crucial for controlling and eradicating diseases, reducing morbidity and mortality rates, and achieving herd immunity within populations. Vaccination is considered one of the most effective public health interventions, resulting in significant declines in the incidence of vaccine-preventable diseases.