Vaccines are made up of either live or killed pathogens (bacteria and viruses) that cause an immune reaction in the body. Then, during a natural infection, the immune system remembers seeing this pathogen and can kill it easier. This is what we call immunity.
Dogs get exposed to numerous pathogens on a daily basis, some of which the animal has natural immunity for and some that are so virulent that they need vaccines to induce immunity so the pathogen does not kill them. Continue reading