Do you need a tetanus shot whenever you get injured?

Author: Liu Shuang, attending physician at Peking Union Medical College Hospital

Reviewer: Zhu Huadong, Chief Physician, Peking Union Medical College Hospital

In daily life, we are often asked questions like: "Doctor, I accidentally cut my hand. Do I need a tetanus shot?" "My child's foot was pierced by a rusty iron nail and is bleeding. Does he need a tetanus shot?" Let us take you to learn about the relevant knowledge about tetanus and tetanus shots.

Tetanus is caused by Clostridium tetani invading the human body through breaks in the skin or mucous membranes, multiplying in an anaerobic environment and producing exotoxins in the body, causing a serious disease characterized by sustained tonic contractions and paroxysmal spasms of skeletal muscles throughout the body. In the absence of medical intervention, the mortality rate of severe patients is close to 100%. It is an extremely serious and potentially fatal disease. Theoretically, as long as there is a wound, there is a risk of tetanus infection. Therefore, once injured, people's first reaction is to get a tetanus shot, and it is correct to have such an idea. Here is an introduction to the so-called "tetanus shot."

Figure 1 Copyright image, no permission to reprint

There are two types of tetanus shots:

The first is tetanus passive immunization preparation, including horse serum tetanus antitoxin (TAT) and tetanus human immunoglobulin (HTIG). Immunity can be obtained immediately after injection. Its main function is to be used for short-term and emergency prevention of tetanus, but the protection period is short, generally 10 to 28 days.

The second type is tetanus active immunization preparation, that is, tetanus toxoid vaccine (TTCV), including adsorbed tetanus vaccine (TT), adsorbed diphtheria and tetanus combined vaccine (DT) and diphtheria, pertussis and tetanus vaccine (DTaP). After vaccination, the human body can produce an acquired immune response with a long effective protection time. After completing the full course of immunization, the protective effect can reach 5 to 10 years.

According to the national immunization plan, children born after 1989 have received four injections of DTP vaccine (under 1.5 years old) and one injection of DTP vaccine (under 6 years old), which means they are fully immunized. Therefore, children who have received full immunization and have received the last injection within 5 years, that is, children under 11 years old, do not need to receive any type of tetanus shot after the wound is properly treated.

Figure 2 Copyright image, no permission to reprint

People born before 1989 do not have tetanus antibodies by default because of different immunization schedules. After these people are injured and bleed, they should be treated differently according to wound contamination and immunization history. If there is a history of full immunization, 11 to 16 years old, clean wounds, and no tetanus injection is required; if it is a contaminated wound, or all wounds with a full immunization history for those over 16 years old, only one shot of tetanus vaccine is needed; for those who are not fully immunized or whose immunization history is unclear, clean wounds require three injections of tetanus vaccine to establish full immunity (immediately after injury, 1 month after injury, and 6 months after injury). If it is an unclean or contaminated wound, in addition to three injections of tetanus vaccine, one injection of tetanus antitoxin or tetanus human immunoglobulin is also required after the injury. But be careful, if you are not sure whether the wound is clean, you need to come to the hospital as soon as possible for the doctor to judge.

Figure 3 Copyright image, no permission to reprint

Finally, it is emphasized that early, timely, correct and effective treatment of wounds is the key to preventing tetanus.