Article Outline Active immunization Passive immunization Immunization and public health. Vaccines provide immunity by causing the body to manufacture disease-fighting substances called antibodies. Serums furnish immunity by adding antibodies directly to the blood. There are two types of immunization.
Active immunization involves the use of vaccines, and passive immunization uses serums.
Active immunization is another term for vaccination. A vaccine contains substances that stimulate the body's immune system to produce antibodies against a particular infectious disease. These antibodies protect the person if he or she is exposed to the actual disease-causing organism. Vaccines contain substances that are powerful enough to trigger antibody production but that do not actually cause disease. Many vaccines consist of disease-causing bacteria or viruses that have been killed.