<s>[INST] What is HIV and AIDS? [/INST] HIV stands for human immunodeficiency virus, which is the virus that causes HIV infection. The abbreviation “HIV” can refer to the virus or to HIV infection.

AIDS stands for acquired immunodeficiency syndrome. AIDS is the most advanced stage of HIV infection.

HIV attacks and destroys the infection-fighting CD4 cells (CD4 T lymphocyte) of the immune system. The loss of CD4 cells makes it difficult for the body to fight off infections, illnesses, and certain cancers. Without treatment, HIV can gradually destroy the immune system, causing health decline and the onset of AIDS. With treatment, the immune system can recover. Source: NIH. Link: https://hivinfo.nih.gov/understanding-hiv/fact-sheets/hiv-and-aids-basics. Field: Infectious Disease. Disease: HIV </s>