How Do Vaccines Work With the Immune System?
-
Immunity Types
-
There are two different types of immunity. The first is passive immunity, which occurs when a person is given antibodies to a disease---they do not produce the antibodies themselves. Passive immunity is acquired when a person is given blood or blood products, such as immune globulin, that contain antibodies. An infant can also acquire passive immunity from its mother.
The second type is active immunity, which occurs when a person's immune system produces the necessary antibodies in response to the presence of a disease organism. Active immunity can occur both with a vaccination and through exposure to the actual disease.
Passive immunity is immediate. Active immunity can take a few weeks to develop. However, active immunity lasts longer.
Alive or Dead
-
Vaccines can contain dead or live-attenuated viruses. Vaccines that use dead viruses include the flu and the bubonic plague. Live-attenuated virus vaccines have been rendered harmless; they are used for diseases like measles or mumps. These usually result in a longer immunity period than do vaccines containing dead matter.
-
Immunity System Response
-
When a vaccine is introduced into the body, it triggers the immune system to target the foreign microorganisms and destroying them. The immune system is then able to recognize the foreign microorganisms the next time they are introduced to the body, and can destroy them before they have the chance to enter cells and multiply.
Antibody Anatomy
-
The antibodies that the immune system develops to fight infection are proteins. White blood cells called B cells, also called lymphocytes, manufacture the antibodies. The B cells remember the "blueprint" for specific antibodies and manufacture enough of them so they are available to fight any future infections. Antibodies are disease-specific. For example, antibodies created for chicken pox will not be able to fight yellow fever.
Exceptions to Immunity
-
A person's immunity may be compromised due to preexisting conditions such as HIV infection or diabetes. Lowered immunity can also occur due to steroid use or because the immune system is not able to manufacture antibodies for a particular disease. This specifically occurs when the immune system lacks B cells. When B cells are triggered (by either a vaccine or exposure to the disease), they manufacture specific antibodies for that particular disease. However, even if the vaccination does not fully work, the disease that develops may still be weakened.
-
