I got a tetanus booster shot this week (recommended by the CDC to be done every 10 years for adults).
The vaccine offers protection against a troublemaker bacterium called Clostridium tetani. Its nearly invincible spore form can be commonly found in soil. So stepping onto a rusty nail with bare feet – or really any cut in the skin – can let the bacterium in. Once inside one’s muscle tissue, it can start producing tetanospasmin, a toxin second only to botulinus for potency. The toxin attacks the central nervous system. An early symptom of an attack includes spasming of jaw muscles.
The tetanus vaccine contains tetanus toxoid, a chemically sterilized tetanus toxin that stimulates one’s immune system to produce antigens that are able to attack and dismantle active tetanus toxin.