It's usually OK to receive an extra booster of the tetanus vaccine. This is especially true if you're being treated for an acute injury, such as a deep cut or puncture wound, and you can't recall exactly when you had your last tetanus shot.
Vaccination is the best way to prevent tetanus — a serious disease caused by a bacterial toxin that affects the nervous system. Tetanus bacterial spores can enter your body through any cut or scratch. But deep puncture wounds, such as from stepping on a nail, are most susceptible to tetanus infection.
An adult who's never been immunized against tetanus should complete the initial tetanus series of three tetanus shots. The first two shots are given at least four weeks apart, and the third shot is given six to 12 months after the second shot. After the initial tetanus series, booster shots are recommended every 10 years. Although getting tetanus shots more frequently generally isn't harmful, it may increase the risk of soreness or redness at the injection site.
If you experience a puncture wound and it's been more than five years since your last tetanus shot — or you can't remember when you had your last tetanus shot — it's best to get the booster shot.