The full name of the tetanus shot is tetanus antitoxin serum, which is mainly made from horse serum and has certain allergenic properties. If a patient is allergic to tetanus antitoxin serum, desensitization injections can be used, which involves gradually injecting one milliliter of the tetanus antitoxin serum into the body in four or more sessions, with each injection spaced about twenty to thirty minutes apart. After each injection, it is important to closely observe the patient's reaction, including checking for signs of itching in the nose, hives throughout the body, or difficulty breathing. If any of these symptoms occur, emergency treatment should be administered. If the injections of tetanus antitoxin serum cannot be completed multiple times, or if the patient is unwilling to accept this method of injection, tetanus immunoglobulin can be administered instead of tetanus antitoxin serum. Tetanus immunoglobulin does not require a sensitivity test and can be directly injected into the body without causing an allergic reaction, although it is more expensive.