Why anti tetanus serum is first injected to tetanus toxoid?

Anti-tetanus serum is injected first to provide immediate passive immunity against tetanus toxins in case of a recent injury or exposure, as it contains pre-formed antibodies. Tetanus toxoid, on the other hand, is used to stimulate the body’s immune system to produce its own antibodies for long-term protection. Administering the serum first ensures that the patient has immediate protection while the active immune response from the toxoid develops over time. This combination approach maximizes both immediate and sustained immunity.