This is very common question among people. I will try to explain the proper guidelines in a simplest possible way... Tetanus prophylaxis (prevention of tetanus) starts with a Primary Immunization which includes a series of 3 doses of Tetanus Toxoid(TT) given as follows, TT dose 1 TT dose 2: 4 to 8 weeks after the first dose TT dose 3: 6 to 12 months after 2nd dose After the completion of primary immunization, a booster dose of TT will be required every 10 years. If a dose is given sooner as part of wound management then the next booster is not needed for 10 years thereafter. Now here's the guidelines for tetanus toxoid in case of an injury/wound There can be 2 different scenarios: Scenario-1: When history of tetanus toxoid given is Unknown or less than 3 doses were given(i.e. primary immunization was incomplete) 2. Scenario-2: when the patient had received 3 or more doses previously( i.e. primary immunization was incomplete) Now in case of scenario-1: 1. If the wound is minor and clean then a tetanus toxoid is required. 2. If the wound is large/contaminated with dirt, soil, saliva; punctured wound, avulsions, wounds resulting from crushing or burn etc...you need to go to a physician ASAP as you may require Tetanus Immunoglobulin(TIG) apart from tetanus toxoid. In case of scenario-2: 1. If the wound is minor and clean: tetanus toxoid is not required if the last dose was giver less than 10 years ago, otherwise TT is required. 2. If the wound is large/contaminated with dirt, soil, saliva; punctured wound, avulsions, wounds resulting from crushing or burn etc...Tetanus toxoid is not required if the last dose given was within last 5 years otherwise a tetanus toxoid is required.