If you step on a piece of glass do you need a tetanus shot?

Any skin opening: An untreated foot laceration that clogged thru the swamp, mud & dirt would be the prime illustration of tetanus risk. Yet, a simple shallow opening in the skin, contaminated by tetanus spores ( that are all around us but predominantly outside in dirt) could give you tetanus. You put yourself at risk every time you let your system weaken & the booster is simple & readily available.