What Is the Connection between HIV and the Immune System?

The connection between the human immunodeficiency virus (HIV) and the immune system is a strong one, because the virus destroys the cells that protect the body against other infections. Once enough of the immune system cells have been destroyed, the body is unable to defend itself from other infections. Lacking an outright cure, treatment for both HIV and the immune system focuses on slowing the disease's progression.

HIV is a viral precursor to Acquired Immunodeficiency Syndrome (AIDS), a condition that causes the body’s immune system — its protection against other types of infection — to stop working correctly. The virus first came to widespread worldwide attention in the early 1980s, though a subsequent review of older medical cases identified an HIV-related death as early as 1968 and other, earlier cases are suspected. As of 2011, there are a number of treatments for HIV, but there is still no known cure for the virus.

There is a strong link between HIV and the immune system. One of the effects HIV has on the body is to destroy a type of cell called a CD4 helper lymphocyte. This cell makes up part of the body’s immune system and is essential for fighting infection and preventing the spread of other types of disease in the body. A healthy human body has a strong immune system that protects itself from most infections, and this is essential for survival.

Over time, as more and more of these essential cells are destroyed by the HIV virus, the body becomes unable to defend itself against other types of infection. In other words, the immune system becomes so weak that infections that usually would have little effect on the body become much more dangerous. It is this vulnerability to other viruses, rather than HIV itself, that can end up proving fatal. Treatment for HIV and the immune system focuses on slowing down the rate at which immune system cells are destroyed, and it can be effective at delaying the onset of AIDS for years.

Although HIV and the immune system are closely linked after the initial infection, a person doesn’t need to have a weak immune system to get HIV to begin with. Some of the most common causes of the virus spreading include unprotected sex or sharing a needle with an infected person. People with an existing sexually transmitted disease are thought to be at a greater risk of getting HIV. It is not possible to spread HIV through coughing, holding hands or being bitten by a mosquito.