The duration of effectiveness for a tetanus shot depends on the specific type of injection used, as different injections vary in their duration of protection. Generally, the protection lasts about two to three days. In cases of infection, it is usually necessary to administer the vaccine within 24 hours. Under these circumstances, a period of about two to three days can be used to clean the wound, thereby achieving the best preventive effect. Additionally, there are other vaccines that are ten to twenty times more effective than this type of vaccine, with a typical prevention time ranging up to 15 days or even about a month. Of course, after receiving the tetanus vaccine, it is important to monitor for any allergic reactions, as different injections may vary in their degree of allergenicity, and individual reactions can differ based on personal health conditions.