The virus is contained in two ways, either by macrophages and phagocytes, or by killer T cells. Macrophages and phagocytes both contain the virus by engulfing it and breaking it down using enzymes and lysosomes (Delves). Killer T cells “recognize the antigens of the pathogen” and kill the cell by inducing apoptosis, “thereby preventing spread of the infection to neighboring cells” (Mayer, Nyland). Killer T cells also immobilize infected cells by injecting a substance called perforin, which penetrates the wall of the infected cell and makes a hole in it, causing a leak of fluids and electrolytes and ultimately leading to their death (Menche, et al). Antibodies also play a vital role in neutralizing viruses. Menche et al. explains that antibodies can neutralize pathogens by “attaching directly to the surface of a virus…and preventing the pathogen from attaching to and infecting a normal cell in the body.” After successfully eliminating the virus, the helper T cells activate a regulatory T cell by releasing hormones called lymphokines. These hormones are responsible for regulating the immune system. Once the virus is destroyed, regulatory T cells reduce the activity levels of B cells and other T cells by releasing their own set of lymphokines, called suppressor factors. The immune system is a formidable system, made up of many complex parts. These parts