Pub. date: 2008 | Online Pub. Date: April 21, 2008 | DOI: 10.4135/9781412963855 | Print ISBN: 9781412941860 | Online ISBN: 9781412963855| Publisher:SAGE Publications, Inc.About this encyclopedia
Acquired immunity is the cumulative development over a lifetime of the body's ability to fight off disease caused by invading agents with antibodies and specialized lymphocytes, one type of white blood cells. Each person's immune system is unique, defined by genetic coding with an ability to distinguish self-cells from foreign invaders, with some exceptions, including autoimmune diseases or immunodeficiency. The immune response can be activated through either active or passive means. Active immunity is the development of an immune response by exposure to either the disease or by vaccination. Exposure to the invading agent and developing the illness activates the immune system for recovery and stores the information in memory cells. Immunizations stimulate body tissues to form antibodies and develop memory cells to store information without causing the illness. Passive immunity provides protection after exposure to a pathogen by direct injection of specific antibodies and ...