A bacteria is a prokaryotic microorganism that can either be beneficial, or harmful to the body. A virus is acellular, and has no cellular structure, and needs a living host to survive; it causes illness in the host, which causes an immune response. Bacteria are alive and can be treated with an antibiotic if it is harmful to the body. Since viruses are considered nonliving, the virus itself cannot be eliminated, but the symptoms can be treated. Another thing a virus can do that a bacteria can't is genetically program itself into the cells, which means that if you get it once, the symptoms can show up throughout the course of the human's life.
