What is a vaccination? How does it confer immunity to a disease?

A vaccination is the process of introducing a weakened or dead form of a pathogen or its proteins into the body, stimulating the immune system to develop immunity against the specific disease. When a pathogen enters the body, the immune system produces B-cells and antibodies to eliminate it. During this response, memory cells are created, which remember the pathogen's unique characteristics, enabling the body to quickly neutralize it in future encounters. Vaccination exposes the immune system to a harmless version of a pathogen, promoting the production of memory cells, thus providing immunity against future infections. Consequently, vaccines prevent the spread of diseases, protect communities, and save lives.