MODEL RELEASED. Tetanus booster. Boy, aged 5-10, receiving a tetanus (lockjaw) booster injection in his upper arm. This booster reinforces the tetanus immunisation given to babies as part of a triple DPT vaccination against diphtheria, pertussis (whooping cough) and tetanus. Tetanus boosters are usually given to children just before starting school. Vaccination does not give total protection against infection, but it reduces the chance of serious illness developing. Tetanus is caused by the Clostridium tetani bacterium which lives harmlessly in the soil and human intestine. It causes lockjaw after infecting a wound, causing muscle stiffness, spasms and possibly death.