It's not the virus that we succumb to, it's the infection that the virus creates. No, antibiotics do not work on viruses, but they do combat the bacterial buildup of, say, pnuemonia that can occur with the flu. Viruses create an immune response, which causes your temperature to rise, your mucus membranes to react, and your lungs to actively prevent fluid from collecting. When someone has an accute reaction to a viral infection, such as accute respiratory distress syndrome or ARDS, that is when the body has gone into overdrive, exhausting itself to the point where it may not be able to recover. If your temperature reaches 104 degrees, your brain starts to cook. Rubella is particularly harmful to pregnant women; they may have mild to medium symptoms, but Rubella has been know to cause physical and mental birth defects while the baby is still in utero. If you think living in an iron lung sounds fun, don't get the polio vaccine. Hepatitis is fun too.