A secondary infection can happen when an alternate contamination, known as the essential contamination, makes a man more defenseless to ailment. It is known as an optional contamination since it happens either after or as a result of another disease. As such, it is auxiliary to that contamination. A primary infection can expand vulnerability to ailment in a few ways. It can modify the adequacy of the resistant framework. It can likewise make it less demanding for the optional disease to get into the body. The deft contaminations related with AIDS are a decent case of the sorts of auxiliary diseases that happen when an illness adjusts the safe reaction. They happen in light of the fact that the body is never again ready to fend off microorganisms or infections that a solid invulnerable framework can typically repulse.