Generally, if the wound is deep dermal or even muscular, narrow and dirty, and not fully cleaned and sterilized by yourself, you will need an active tetanus shot. Tetanus is caused by spores that enter the body through the wound. Anaerobic spores that are dormant will quickly turn into active tetanus bacilli under anaerobic conditions, releasing exotoxins, i.e. tetanus spasmodic toxin, into the bloodstream, which will invade the body’s central nervous system and cause corresponding neurological symptoms. Therefore, tetanus infection requires certain pathogenic conditions, which must be formed in the wound anaerobic microenvironment, such as narrow and deep, soil-contaminated wounds; necrotic tissues, local blood supply of poor wounds and so on. If the wound is only a minor epidermal abrasion and is sterilized and cleaned, the chances of contracting tetanus are generally very low, and a tetanus shot can be dispensed with. Consult a medical professional for details.