system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How exactly do tetanus shots work?

I know is it's a shot for wounds that potentially could have rust or something else that you wouldn't want in an open wound. But how do they work?
gpt
Tetanus is a bacteria that can sometimes live on rusty things. It is very rare but can be potentially deadly. The shot is a vaccine which teaches the immune system how to identify and thus eradicate the bacteria before they become problematic.