What is the primary role of vaccines?

Vaccines primarily function by stimulating the immune system to develop immunity to a disease. This is achieved by introducing a harmless component of the pathogen—such as an inactivated virus, a weakened form of the pathogen, or a piece of its genetic material. This exposure allows the immune system to recognize and remember the pathogen without causing the disease itself. Consequently, if the vaccinated individual is later exposed to the actual pathogen, their immune system can respond more swiftly and effectively, often preventing illness or reducing the severity of the infection.

This immune response includes the production of antibodies and the activation of specific immune cells, setting up a "memory" that allows for faster and more robust responses to future infections by the same pathogen. This is fundamentally different from curing a disease, which involves treating an active infection, or providing immediate symptom relief, which targets the effects of an existing illness. Vaccines do not replace the need for a healthy diet; rather, they complement overall health by preventing certain diseases that could undermine well-being.