USA HISTORY

Detailed explanation-1: -Natural immunity is acquired from exposure to the disease organism through infection with the actual disease. Vaccine-induced immunity is acquired through the introduction of a killed or weakened form of the disease organism through vaccination.

Detailed explanation-2: -Innate immunity: Everyone is born with innate (or natural) immunity, a type of general protection. For example, the skin acts as a barrier to block germs from entering the body. And the immune system recognizes when certain invaders are foreign and could be dangerous.

Detailed explanation-3: -Potential mechanisms of natural resistance include host genetic variants, viral interference, cross-protective natural antibodies, T cell immunity, and highly effective innate immune responses.

Detailed explanation-4: -Immunity means com-plete resistance to disease; immune means not subject to attack by a path-ogenic organism or virus.

Detailed explanation-5: -Immunity can be defined as all of the physiological mechanisms that enable an individual’s body to recognize materials as foreign and to neutralize, eliminate, or metabolize them without injury to its own tissue.