The tetanus shot is included in a variety of vaccines, usually also protecting against diphtheria and pertussis. Tetanus, also called lockjaw, is caused by the bacteria Clostridium tetani. It can be found in dust, soil, and manure. If it enters the body through a cut in the skin, it can cause tetanus, which has the potential to be life-threatening. In order to be fully protected, you need to get the tetanus shot every 10 years.