The body's immune system is like any other system of the body. Each of them have their vital function for the human host.

The immune system's goal is to protect the body against invaders either from without, such as microbes, or from within, such as cancers and different types of neoplastic transformation.

Investigating rare diseases gives researchers more clues about how the healthy immune system functions.

When you vaccinate someone, or when you get infected, the microbe is presenting itself to the immune system in a way that the immune system recognizes the important elements of the microbe and makes an immune response, both an antibody response and a cellular response, to ultimately contain the microbe.

There is an urgent need for a protective Ebola vaccine, and it is important to establish that a vaccine is safe and spurs the immune system to react in a way necessary to protect against infection.

Historically, a live vaccine induces more potent, lasting and broader immune responses than a killed vaccine. The body is seeing the microbe in a way that is much more analogous to a real infection.