Usual Pediatric Dose for Tetanus Prophylaxis. >=7 years Primary Immunization Series of three doses: mL IM of tetanus toxoid adsorbed once, followed by a second dose 4 to 8 weeks later, and the third dose given 6 to 12 months after the second dose. Routine Booster injection: mL IM of tetanus toxoid adsorbed or mL IM...