What is the causative factor for acquired immune deficiency syndrome (AIDS)?

Acquired immune deficiency syndrome (AIDS) is specifically caused by the human immunodeficiency virus (HIV). HIV attacks and weakens the immune system, particularly targeting CD4 cells, which are crucial for the immune response. Over time, without treatment, the virus can lead to the advanced stage of HIV infection known as AIDS, where the body becomes unable to fight off opportunistic infections and diseases.

This understanding emphasizes the significance of HIV in the context of public health and medical treatment. The other viruses listed, such as the Epstein-Barr virus, influenza virus, and hepatitis B virus, are not responsible for causing AIDS, although they can cause other illnesses and have their own impacts on health. Each virus has a distinct mechanism and effects on the body, but only HIV leads to the specific condition characterized by immune deficiency known as AIDS.