For more information, see the Td (Tetanus, Diphtheria) vaccine information statement.
The tetanus-diphtheria (Td) vaccine protects against toxins produced by the tetanus and diphtheria bacteria, not against the bacteria itself. There is also a combination vaccine that adds protection against pertussis (diphtheria-tetanus-pertussis vaccine).
Typically, the tetanus bacteria enter the body through a wound and begin to grow and produce the toxin. The toxin causes severe muscle spasms and can be fatal. Therefore, vaccination is particularly important.
Diphtheria usually causes inflammation of the throat and mucous membranes of the mouth. Also, the bacteria that cause diphtheria produce a toxin that can damage the heart, kidneys, and nervous system. Before routine vaccination became available, diphtheria was a leading cause of death in children.
A diphtheria-tetanus-pertussis vaccine is typically given during childhood. This combination vaccine is given in five injections, followed by a booster that contains the same amount of tetanus vaccine but a smaller amount of diphtheria and pertussis vaccine. The booster is given at age 11 to 12 years. Because immunity against pertussis is decreasing, people over age 16 should receive this booster if they have not received it previously.
The tetanus-diphtheria vaccine is given as a booster every 10 years after the diphtheria-tetanus-pertussis booster is given at age 11 to 12 years. Also, people sometimes need to be vaccinated after an injury that breaks the skin.