At Vaxopedia, pediatician Vince Iannelli is compiling facts to defeat myths. Here's one:
If a puncture wound bleeds a lot, then you don’t need to get a tetanus shot. (False)
Many puncture wounds do not bleed a lot, but those that do are still at risk for tetanus.
You don’t need to get a tetanus shot if you have a clean, minor wound and:
you have completed a primary tetanus series (a minimum of 3 tetanus containing vaccines), and
your most recent dose of tetanus vaccine was within the past 10 years
For most other wounds, including dirty wounds, animal bites, and puncture wounds, etc., you likely don’t need a tetanus shot if you have completed a primary tetanus series, and your most recent dose of tetanus vaccine was within the past 5 years.
In addition to a dose of tetanus vaccine, if has been less than 5 years since their last dose or they are unvaccinated or incompletely vaccinated, then they might also need to get tetanus immune globulin (TIG).
How much the wound bleeds has nothing to do with whether or not you need a tetanus shot. After all, a bleeding wound is not going to flush out all of the tetanus spores that might have contaminated your wound, or at least you have no guarantee that it did. What if the bleeding was more superficial and there was a deeper puncture wound that you couldn’t see?