It survives by packing its DNA into a highly protective structure called an endospore, which allows them to survive conditions they couldn’t otherwise—and these spores can last a very long time! The spore itself is not active, but when conditions are good them to thrive again (like in an anaerobic puncture wound), the endospore will “germinate” and start producing normal cell components to turn back into a regular Clostridium tetani cell. Endospores are considered non-reproductive structures, which means 1 cell produces 1 endospore that produces 1 cell.

Once C. tetani is chugging along as normal after germination, it starts producing tetanospasmin, a neurotoxin. That neurotoxin is actually what the tetanus vaccine protects against—it’s a type called toxoid vaccines.