Detail of a blood vessel with HIV virus attacking the white blood cells. The white blood cells protect the body against infections.

HIV

A virus (human immunodeficiency virus) that affects the natural immune system. When someone with HIV does not take medicines, the infection becomes worse and can develop into AIDS. HIV cannot be cured, but HIV medicines can keep the virus under control. HIV is a sexually transmitted infection (STI). A condom protects against infection with HIV.