Immunity – A Brief Review

Abstract

The immune system provides the body’s defense network against infection. The body is continuously exposed to disease causing microorganism. An intact immune system provides adequate protection from most of the infection in a healthy individual. Immunity is defined as the state of resistance exhibited by the host towards injury caused by microorganisms or their products. It is the ability of an individual to recognize and defend against infection. There are two types of immunity: Native immunity and adaptive immunity. Vaccines are preparations of live or killed microorganism or their products used for immunization.