the process of rendering a subject immune, or of becoming immune. Called also
inoculation and
vaccination. The word
vaccine originally referred to the substance used to immunize against
smallpox, the first immunization developed. Now, however, the term is used for any preparation used in active immunization.
The Centers for Disease Control and Prevention has an Advisory Committee on Immunization Practice that reviews childhood immunization schedules yearly. The recommended childhood immunization schedule is reprinted in Appendix 7-1. In Canada, the Health Protection Branch Laboratory Center for Disease Control, Health Canada, National Advisory Committee on Immunization publishes a recommended childhood vaccination schedule for Canada (reprinted in Appendix 7-3). Adult immunization schedules for the United States and Canada are found in Appendices 7-2 and 7-4.
active immunization stimulation with a specific antigen to promote antibody formation in the body. The antigenic substance may be in one of four forms: (1) dead bacteria, as in
typhoid fever immunization; (2) dead viruses, as in the Salk
poliomyelitis injection; (3) live attenuated virus, e.g., smallpox vaccine and Sabin polio vaccine (taken orally); and (4) toxoids, altered forms of toxins produced by bacteria, as in immunization against
tetanus and
diphtheria.
Since active immunization induces the body to produce its own antibodies and to go on producing them, protection against disease will last several years, in some cases for life.
Active immunization is not without risks, although research supports the efficacy of immunization programs as a measure to reduce the incidence of infectious disease. Paradoxically, the more successful an immunization program and the higher the immunization rate, the more likely it becomes that a vaccine will cause more illness and injury than its target disease. Thus the risk of disease is less threatening than the risk of an adverse reaction to the vaccine that will prevent it.
In an effort to immunize larger numbers of children against preventable infectious diseases public health officials and health care professionals in the 50 states, the District of Columbia, Puerto Rico, the Virgin Islands, and Guam now enforce laws requiring children to be immunized before they enter school. Those children who come to school with incomplete or nonexistent records of immunizations are refused admittance until they are immunized.
Circumstances that require postponement of immunization include acute febrile illness, immunologic deficiency, pregnancy, immunosuppressive therapy, and administration of gamma globulin, plasma, or whole blood transfusion 6 to 8 weeks prior to the scheduled immunization.
Because of their potential for triggering
anaphylaxis in hypersensitive persons, all immunizing agents should be given with caution and only after a health history has been completed on the patient. Emergency equipment and drugs should be readily at hand in all clinics and other facilities where immunizing agents are administered.