Immunity: Active or Passive?
Immunity is the ability of a body to guard itself from diseases. Immunity can either be natural or artificial. Also, they can be active and passive. Active immunity occurs naturally in a person while passive immunity is triggered by an external force. Ensuing are important points that explain and distinguish active and passive immunity.
Active immunity requires something to trigger a response which is produced from an individual’s immune system. In active immunity, the individual itself produces the antibodies to counter an antigen. Though long lasting, it is a slow process and takes quite some time to respond to the antigen (antibody generator). When an individual comes in contact with an antigen, the individual’s immune system naturally creates antibodies in a slow process. However, on subsequent attacks from the same antibody, the immune system’s response to it is faster and more efficient than the last time.
Natural Active Immunity
Natural active immunity occurs when an individual comes in natural contact with an antibody. The immune system creates its defense against the antibody by the eventual production of antibodies.
Artificial Active Immunity
To artificially immunize an individual, a weakened or killed version of the same antibody is used against which the immunity is sought. This ensures that when the individual comes in natural contact with this antigen later, the immune system is already equipped with the antibodies to tackle it. Artificial immunity is administered by way of vaccines. Some vaccines provide long-term protection against the antigen while some provide a short-term protection. This is why some vaccines like polio have to be administered periodically to a child. Administration of artificial active immunity is less prone to causing any side effect.
Passive immunity requires the administration of pre-synthesized elements of the immune system. Such an external administration entails that the body itself will not have to produce the same antibody. To provide passive immunity, antibodies are externally transferred from people already having it to those who do not. It can be natural as is in the case of a mother to her child. Passive immunity is also administered externally and though it begins to work quickly, it has a short lasting effect.
Natural Passive Immunity
when there is an immunity transfer from a mother to her child through the placenta at birth, it is called Natural passive immunity.
Artificial Passive Immunity
In case of a sudden outbreak of a disease, artificial passive immunity is provided by the administration of pre-synthesized antibodies through an injection to the body. It is an emergency treatment provided to the body against any foreign toxic elements. Artificial passive immunity is also provided through blood transfusion. The body may react to the administration due to the antisera causing serum sickness. Before administration however, tests are made to ensure that the individual’s body will cope and adapt to it.
Active and passive immunity together strengthen an individual’s immune system and lower the vulnerability ratio.