A tetanus shot is a vaccine that protects you from getting tetanus. Tetanus, also called “lockjaw,” is a serious disease caused by bacteria called Clostridium tetani . When you get tetanus vaccines as recommended, your body makes antibodies, special proteins that will help your immune system fight the toxin produced by the bacteria.
Clostridium tetani are bacteria that live in soil and manure. Tetanus infections most commonly happen when you suffer a wound that gives the bacteria a chance to enter your body. For example, stepping on a nail is a common cause of tetanus infections. Once inside your body, the bacteria release a toxin that causes your muscles to tighten. This can cause your mouth to “lock” shut and make it hard to swallow. If not treated promptly, the muscle stiffness spreads and, in some cases, can cause death.
Tetanus is now rare in the United States, in large part because of vaccinations and improved wound care. People who work with soil, sewage, or animals are more likely to be exposed to Clostridium tetani bacteria in the event of an injury. In the United States, tetanus infections are more likely to be fatal in people over the age of 65 and people with diabetes, but they are serious in all individuals.