Innate immunity is an antigen-nonspecific defence mechanisms that a host uses immediately or within several hours after exposure to almost any microbe. This is the immunity one is born with and is the...Innate immunity is an antigen-nonspecific defence mechanisms that a host uses immediately or within several hours after exposure to almost any microbe. This is the immunity one is born with and is the initial response by the body to eliminate microbes and prevent infection. Innate immunity can be divided into immediate innate immunity and early induced innate immunity. In this section we will learn about immediate innate immunity.