What type of system does HIV primarily affect?

HIV primarily affects the immune system, which is critical for the body's ability to fight off infections and diseases. Specifically, HIV targets CD4 cells, also known as T-helper cells, which play a pivotal role in the immune response. As the virus infects and destroys these cells, the immune system becomes weakened, leading to a reduced ability to combat not just HIV itself, but also other opportunistic infections and diseases. Over time, this deterioration can result in AIDS (Acquired Immunodeficiency Syndrome), which is the most severe phase of HIV infection characterized by a significantly compromised immune system. This impact on the immune system is what makes HIV particularly dangerous, as the body becomes more susceptible to illnesses that it would otherwise be able to fend off effectively.