HIV, or human immunodeficiency virus, kills cells of the body's immune system. Eventually, this can destroy the body's ability to fight infections and certain cancers.
The most advanced stage of HIV infection is known as AIDS (acquired immunodeficiency syndrome).
NICHD is one of many federal agencies and NIH institutes working to understand HIV. NICHD's research focuses on the biology, prevention, and treatment of HIV/AIDS in infants, children, adolescents, and women, including pregnant and breastfeeding women. Another institute, the National Institute of Allergy and Infectious Diseases, leads HIV/AIDS research at NIH.