What is the difference between active and passive immunity?

1 Answer
May 16, 2018

The main difference between the two types of immunity is that active involves #color(red)("antigens")# and passive involves #color(red)("antibodies")#.


Active Immunity

This kind of immunity is acquired when #color(red)("antigens")# of a pathogen enter an individual's body and an immune response is triggered. #color(purple)("Natural active immunity")# occurs when an individual contracts an illness naturally. For example, they may ingest the cholera virus through contaminated water. #color(purple)("Artificial active immunity")# occurs when an individual is given a weakened form of a pathogen through a vaccine. In both cases, the immune response is triggered, culminating in the production of memory cells that protect the body if a second infection occurs.

Passive Immunity
This occurs when #color(red)("antibodies")# enter an individual. These are essentially molecules that fight and destroy a specific pathogen's antigen. #color(purple)("Natural passive immunity")# occurs when they pass to an infant through the mother's milk. #color(purple)("Artificial active immunity")# occurs when the antibodies are injected into an individual. In both cases, the antibodies destroy the pathogen and grant the individual immunity.