The main effect of HIV (Human Immunodeficiency Virus) is the progressive weakening of the immune system. HIV infects and damages the immune system's CD4 cells, which are responsible for fighting off infections and diseases. As the number of CD4 cells decreases, the body becomes increasingly vulnerable to opportunistic infections and certain cancers. If left untreated, HIV can progress to AIDS (Acquired Immunodeficiency Syndrome), a more advanced stage of the disease in which the immune system is severely weakened, leading to life-threatening infections and conditions.
