Tetanus Toxoid Dosing
For adults and children ≥7 years, the standard dose of tetanus toxoid is 0.5 mL administered intramuscularly, containing 2-10 Lf units of tetanus toxoid in Td formulations or as part of Tdap vaccine. 1
Vaccine Formulations and Composition
- Td (Tetanus-Diphtheria) vaccine contains 2-10 Lf units of tetanus toxoid and ≤2 Lf units of diphtheria toxoid per 0.5 mL dose for individuals ≥7 years 1
- Tdap vaccine contains the same tetanus toxoid dose (0.5 mL) but includes acellular pertussis components 2
- All formulations are adsorbed preparations given via deep intramuscular injection 1, 3
Primary Immunization Series
For unvaccinated individuals ≥7 years, the three-dose primary series follows this schedule: 2, 1
- First dose: 0.5 mL of Tdap (preferred) or Td
- Second dose: 0.5 mL of Td or Tdap at least 4 weeks after the first dose
- Third dose: 0.5 mL of Td or Tdap 6-12 months after the second dose
The series does not need to be restarted if doses are delayed—simply continue from where the patient left off. 2
Routine Booster Dosing
- Standard interval: 0.5 mL every 10 years throughout adult life 1, 4, 3
- Tdap should be given once (except during pregnancy), with all subsequent boosters using Td 5
- For adults who have never received Tdap, give 0.5 mL of Tdap immediately, regardless of interval since last tetanus-containing vaccine 2, 5
Critical pitfall: Administering tetanus boosters more frequently than every 10 years increases risk of Arthus-type hypersensitivity reactions (severe local reactions with pain, swelling, and induration). 1, 4
Wound Management Dosing
The dose remains 0.5 mL, but timing differs based on wound type and vaccination history: 1, 4, 3
For clean, minor wounds:
- Give 0.5 mL if >10 years since last dose
- Tdap preferred if never received; otherwise use Td
For contaminated or tetanus-prone wounds:
- Give 0.5 mL if >5 years since last dose
- Tdap preferred if never received; otherwise use Td
- For incomplete/unknown vaccination history: give both 0.5 mL tetanus toxoid AND 250 units of tetanus immune globulin (TIG) in separate syringes at different anatomic sites 3
Important consideration: Research demonstrates no early antitoxin response within 4 days of booster vaccination, supporting the continued need for TIG in high-risk wounds with incomplete immunization. 6
Special Populations
- 0.5 mL of Tdap during each pregnancy at 27-36 weeks gestation
- Administer regardless of prior Tdap history or interval since last tetanus vaccine
Elderly adults (≥65 years): 1, 4, 5
- Same 0.5 mL dose as younger adults
- Give Tdap if never received (Boostrix preferred, though either product acceptable)
- Continue Td boosters every 10 years thereafter
- Research shows even reduced doses (1.9 Lf) produce excellent immune responses in elderly with minimal side effects 7
Children 7-10 years with incomplete vaccination: 2
- Single 0.5 mL dose of Tdap for catch-up
- Additional doses on catch-up schedule using Td if needed
- Still give adolescent Tdap dose at age 11-12 years
Dosing Algorithm Summary
| Clinical Scenario | Dose | Vaccine Choice |
|---|---|---|
| Primary series (any dose) | 0.5 mL | Tdap for first dose, then Td [2,1] |
| Routine booster | 0.5 mL | Td every 10 years [1,3] |
| Never received Tdap | 0.5 mL | Tdap now [5] |
| Clean wound, >10 years | 0.5 mL | Tdap if never received, else Td [4] |
| Contaminated wound, >5 years | 0.5 mL | Tdap if never received, else Td [4,3] |
| Unknown history + contaminated wound | 0.5 mL + 250 units TIG | Tdap/Td + TIG separate sites [3] |
| Pregnancy | 0.5 mL | Tdap at 27-36 weeks [4,5] |
Never use DTaP (pediatric formulation) in individuals ≥7 years—always use Td or Tdap instead. 2, 4