Recommended Dose of Anti-Tetanus Serum (TIG) for Post-Exposure Prophylaxis
The recommended prophylactic dose of Tetanus Immunoglobulin (TIG) is 250 units intramuscularly for both adults and children with unknown or incomplete tetanus vaccination history who present with tetanus-prone wounds. 1, 2
When TIG is Actually Indicated
TIG is only required in specific circumstances—not for all wounds:
Administer TIG 250 units IM when the patient has received fewer than 3 lifetime doses of tetanus toxoid OR has unknown/uncertain vaccination history AND presents with any wound 1, 2
Do NOT administer TIG if the patient has completed a primary vaccination series (≥3 documented doses), regardless of how long ago the last dose was given, unless the patient is severely immunocompromised 1, 2
Severely immunocompromised patients (HIV infection, severe immunodeficiency) should receive TIG regardless of their tetanus immunization history when they have contaminated wounds 1, 2
Critical Administration Details
Always administer TIG and tetanus toxoid vaccine at separate anatomic sites using separate syringes to prevent interference with the immune response 1, 2
The 250-unit dose applies universally to both adult and pediatric patients—there is no weight-based dosing for prophylaxis 1
Human TIG is strongly preferred over equine antitoxin due to longer duration of protection (approximately 4 weeks versus 7-10 days) and significantly fewer adverse reactions 2, 3
Complete Wound Management Algorithm
For Patients with ≥3 Previous Doses:
Clean, minor wounds: Give tetanus toxoid (Tdap preferred if not previously received) only if ≥10 years since last dose; NO TIG needed 2
Contaminated/tetanus-prone wounds: Give tetanus toxoid (Tdap preferred if not previously received) only if ≥5 years since last dose; NO TIG needed 1, 2
For Patients with <3 Doses or Unknown History:
Any wound type: Give BOTH tetanus toxoid-containing vaccine (Tdap preferred) AND TIG 250 units IM at separate sites 1, 2
These patients must complete a full 3-dose primary vaccination series for long-term protection: second dose at ≥4 weeks, third dose at 6-12 months after the second 2
Tetanus-Prone Wound Classification
Wounds requiring the 5-year (rather than 10-year) interval for booster consideration include:
- Puncture wounds and penetrating injuries (projectiles, crushing mechanisms) that create anaerobic environments 1
- Wounds contaminated with dirt, soil, feces, or saliva 1, 2
- Avulsions, burns, or other nonintact skin with potential contamination 1
- Wounds with devitalized tissue 4
Special Populations and Supply Considerations
Elderly patients (≥60 years): Should be prioritized for TIG if supplies are limited, as 49-66% lack protective antibody levels 1, 2
Immigrants from regions outside North America/Europe: Should also be prioritized for TIG when supplies are limited, as they are less likely to have adequate vaccination history 1, 2
In mass-casualty settings with limited TIG supply, reserve TIG first for persons aged >60 years and immigrants from non-North American/European regions 1
Common Pitfalls to Avoid
Do not confuse the 10-year routine booster interval with the 5-year interval for contaminated wounds—this is the most common error in tetanus prophylaxis 2
Do not give TIG to patients with documented complete primary series unless they are severely immunocompromised—this wastes limited resources and provides no additional benefit 2
Do not assume vaccination history—patients with unknown or uncertain histories should be treated as having zero previous doses 2, 4
Research confirms that tetanus toxoid boosters do not produce protective antibody levels within the first 4 days after administration, even in previously vaccinated individuals, which validates the continued need for TIG in high-risk scenarios 5
Distinction from Treatment Dosing
The 250-unit prophylactic dose is dramatically different from the therapeutic dose used for active tetanus disease, which is 3,000-6,000 units—a 12-24 fold higher dose 6