Vaccines work to protect against diseases by stimulating the immune system to respond more effectively to specific pathogens. They introduce a harmless component of the pathogen, such as an inactivated virus or a piece of its genetic material, prompting the body to create an immune response. This might include the production of antibodies and memory cells, which remain in the body, allowing it to recognize and combat the actual pathogen swiftly if exposed in the future. Thus, vaccines significantly reduce the risk of infection and promote public health.