1. KEY CONCEPT When the immune system is weakened, the body cannot fight off disease.

2. HIV targets the immune system.
The human immunodeficiency virus (HIV) is a retrovirus.
attacks and weakens the immune system
is transmitted by mixing infected blood with a bodily fluid

3. HIV infection leads to AIDS.
T cell
dead T cell
antibody
activated B cell
HIV reproduces in and destroys T cells.
The body cannot replace T cells fast enough.
T cells cannot help in immune responses.

4. AIDS is acquired immune deficiency syndrome.
several opportunistic infections
very low amount of T cells