About HIV/AIDS

Since the beginning of the pandemic, 92 million people have acquired HIV and more than 44 million have died of AIDS-related illnesses.

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What is HIV

HIV stands for human immunodeficiency virus.

It is the virus that causes AIDS. When a person is infected with HIV, the virus enters the body and then resides and multiplies primarily in the white blood cells—the immune cells that normally protect us from disease.

What is AIDS

AIDS stands for acquired immunodeficiency syndrome.

As HIV multiplies in an infected person, it damages or kills specific immune cells, weakening the immune system and leaving the person vulnerable to infections and illnesses ranging from pneumonia to cancer.

Only when someone with HIV begins to experience one or more of these conditions or loses a significant amount of immune cells are they diagnosed with AIDS.

Image accompanying amfAR's Snapshots of an Epidemic HIV/AIDS timeline feature

Snapshots of an epidemic: an HIV/AIDS timeline

Our chronicle of the HIV/AIDS pandemic begins in the summer of 1981, when the first cases of a mysterious and deadly new pathogen come to light.

HIV resources

A wide range of local, national and international organizations conduct research and provide services, information and advocacy for individuals and communities affected by HIV.