Immunity that develops as a result of exposure to pathogens or their toxins.

Herpes Zoster is a disease characterized by painful skin lesions that occur mainly on the trunk (back and stomach) of the body but which can...

A group of cells that help the body defend itself against disease by remembering prior exposure to specific organisms (e.g. viruses or bacteria)....

Infectious agents are organisms capable of spreading disease (e.g. bacteria or viruses).

Your immune system is the complex system in the body responsible for fighting disease. Its primary function is to identify foreign substances...

Hyposensitivity is a condition in which the body has a weakened or delayed reaction to a substance.

Hypersensitivity is a condition in which the body has an exaggerated response to a substance (e.g. food or drug). Also known as an allergy.

Vaccination is an injection (by a health professional, a nurse or doctor) of a killed or weakened infectious organism in order to...

Adverse events are undesirable experiences occurring after immunization that may or may not be related to the vaccine.

Serology is the measurement of antibodies, and other immunological properties, in the blood serum.

Passive immunity is the protection against disease through antibodies produced by another human being or animal. Passive immunity is effective,...

Bone marrow is the soft tissue located within bones that produce all blood cells, including the ones that fight infection.

An antibody is a protein found in the blood that is produced in response to foreign substances (e.g. bacteria or viruses) invading the body....