 We explain HIV and AIDS. The human immune system defends the body against illnesses all the time. It uses guards in the blood called T cells to recognize any intruders and destroy them. But instead of attacking the body, the human immunodeficiency virus, or HIV, attacks those T cells themselves. It turns them into copy machines to make more copies of itself. Then it eventually kills the infected T cells. Without treatment, it takes 8 years on average for a person with HIV to develop AIDS, or acquired immunodeficiency syndrome. By then, there aren't enough T cells to fight off various infections and diseases, so it's not the virus directly, but the diseases that are eventually fatal. Humans first acquired HIV from blood contact with apes, and gradually transmitted it to more people through unprotected sex, used syringes, and childbirth. AIDS remained undiscovered until a sudden outbreak among gay men in New York and San Francisco in 1981. Very quickly, people began developing the same unusual symptoms around the world. The patients suffered from rare forms of skin cancer, pneumonia, or thrush, and few survived. Prejudice against homosexuality made research funding hard to get, and more and more people were getting sick. What could be done? Keep the virus from spreading. It became clear that the best preventive measure was safe sex, as condoms kept the virus from infecting others. Additionally, blood banks started testing blood, and new programs even distributed clean needles to drug users. Finally, in 1987, the first treatment against the virus was released, the ancestor of combination therapy. The medication still isn't a cure, but it keeps the virus from multiplying and destroying the host's immune system. By starting treatment early, people with HIV can now live long, healthy lives. Unfortunately, many people still lack access to medication, especially in sub-Saharan Africa. Over the last 30 years, about 36 million people have died, while 2 million more are infected each year. Scientists have made a lot of progress, but are still looking for the cure. You too can help end the AIDS crisis. Play safe, get tested, donate to support research, prevention, and care. And spread the word.