Chapter 17 Vaccination is the administration of a vaccine into a person’s body to provide immunity against an infection. Immunization is a method used in order to protect a person or an animal resistance to diseases. attenuated is the act of weakening or decreasing the content of a virus or a bacterium in the research centers to make it less harmful. Inactivated is the process of removing or putting an end to questionless organic substances. Toxoid is a chemically altered substance known as toxin used to exterminate poisonous substances but can still withhold its capability to activate immunoglobulin production.