HIV is the human immunodeficiency virus. If you have HIV, you have an infection that damages your immune system over time and causes AIDS. AIDS stands for acquired immunodeficiency syndrome. It is the final stage of an HIV infection when your immune system is damaged and too weak to fight off ordinary infections. When foreign invaders such as bacteria and viruses get into your body, they can cause infections. These events activate your body's defenses. The white blood cells of your immune system are part of your body's defenses. One type of white blood cell called helper T lymphocytes or helper T cells strengthen your immune system's response to infection in two ways. First, helper T cells release chemicals that attract other white blood cells to the site of the infection. Yeah, these additional white blood cells attack the invading bacteria or virus, as well as other infected cells. Yeah, second helper T cells release chemicals that cause other white blood cells to multipl