In the U.S. today, tetanus vaccine is administered only in a combination shot (DTaP, DT, Tdap, Td) that contains vaccines for tetanus (T), diphtheria (D) and possibly pertussis (whooping cough) (P). The U.S. Food and Drug Administration has approved twelve different combination vaccines that include tetanus toxoid vaccine. There are different rules for use of these vaccines by different aged groups. The CDC’s Advisory Committee on Immunization Practices (ACIP) currently recommends administration of a tetanus containing vaccine (DTaP) at two, four, and six months old; between 15 and 18 months old; and between four and six years old. Another booster dose is recommended at 11-12 years of age (Tdap). From a link I also posted