Which virus specifically targets the cells crucial for fighting infection from pathogens?

The Human Immunodeficiency Virus (HIV) is specifically known for targeting the immune system, particularly the cells known as CD4 T cells, which play a crucial role in orchestrating the body's response to infections. By infecting and destroying these cells, HIV compromises the immune system, making it difficult for the body to fight off not only HIV itself but also other pathogens, such as bacteria and viruses. This characteristic leads to immunodeficiency, which is the hallmark of HIV infection and can progress to AIDS (Acquired Immunodeficiency Syndrome) if left untreated.

In contrast, the other viruses listed have different roles and effects on the body. Hepatitis A and Hepatitis B primarily target liver cells and are not known for their effects on the immune system. Hepatitis C also affects the liver but does not specifically target immune cells like HIV does. Therefore, HIV stands out as the virus that directly and significantly impairs the body's ability to combat other infections due to its specific action on the immune system's key components.