Final answer:
Vaccines work by introducing modified pathogens or antigens into the body, triggering an immune response and the production of antibodies. This provides future protection against the actual disease and allows the immune system to respond quickly and effectively.
Step-by-step explanation:
Vaccines work by introducing a modified pathogen or antigen into the body. This exposure triggers an immune response, leading to the production of antibodies by B lymphocytes. The antibodies and memory cells created through vaccination provide future protection against the actual disease, allowing the immune system to fight the pathogen more efficiently and effectively. Vaccines imitate infections without causing illness, priming the body to respond quickly and strongly if it encounters the antigen again.