Antitetanus Serum (ATS) Dosing as Alternative to Tetanus Immunoglobulin (TIG)

Introduction to ATS and TIG

The Centers for Disease Control and Prevention recommends that when human Tetanus Immunoglobulin (TIG) is unavailable, equine Antitetanus Serum (ATS) can be administered at a dose of 1,500-3,000 IU intramuscularly for prophylaxis, or 10,000-20,000 IU for treatment of established tetanus, though this is significantly less preferred than TIG due to higher rates of allergic reactions and shorter duration of protection 1, 2

There is no direct dose equivalency between ATS and TIG - these are fundamentally different products with different potencies, pharmacokinetics, and safety profiles 1, 2
The standard prophylactic dose of human TIG is 250 units IM for both adults and children, administered at a separate site from tetanus toxoid 1, 2

ATS should only be used when human TIG is unavailable, particularly in resource-limited settings where TIG supply is inadequate 1, 2

Human TIG is strongly preferred over equine ATS when available due to significantly lower risk of allergic reactions and longer duration of protection 3

Always administer tetanus toxoid vaccine concurrently with either TIG or ATS, but at a separate anatomic site using a separate syringe to prevent interference with immune response 1, 2
Neither TIG nor ATS can reverse damage from toxin already bound to neural tissue - they only neutralize circulating toxin 3
Patients receiving ATS or TIG still require completion of the primary tetanus vaccination series, as passive immunization does not confer long-term immunity 3, 4
Natural tetanus infection does not confer immunity, so even patients recovering from tetanus must receive active immunization with tetanus toxoid 3