◆Tetanus

Tetanus is an extremely serious acute infectious disease caused by Clostridium tetani invading the human body through skin or mucous membrane wounds, growing and multiplying locally in the wound and producing toxins. 

After Clostridium tetani enters the human body, it produces exotoxin with spasmodic toxicity and hemolytic toxicity. It is extremely toxic and can cause functional changes in the human central nervous system. The main clinical manifestations are trismus, general muscle rigidity and paroxysmal spasms. feature. Severely ill patients can suffer from suffocation, laryngospasm, lung infection, organ failure, etc., posing a fatal threat to the patient’s life and health.

Tetanus spores widely exist in the natural environment, and humans generally have no natural immunity to tetanus. Therefore, artificial immunization is needed to make the body develop immunity to tetanus toxin. There are two methods: active immunity and passive immunity. Vaccination against tetanus is an active immunization.

◆Mechanism

The main component of the tetanus vaccine is tetanus toxoid (TT), which is made from attenuated tetanus exotoxin. Active immunity against tetanus is to inoculate the human body with tetanus toxoid, causing the body to produce antibodies against the tetanus toxin, thus acquiring immunity.

◆Vaccine classification

Currently, the vaccines used to prevent tetanus in my country include the following five types:

•Adsorbed acellular diphtheria-tetanus pertussis combined vaccine (DTaP): Made from acellular pertussis vaccine stock solution (co-purification process), diphtheria toxoid stock solution and tetanus toxoid stock solution with aluminum hydroxide adjuvant. Used to prevent whooping cough, diphtheria, and tetanus.

•Acellular diphtheria-tetanus pertussis and Haemophilus influenzae type b conjugate vaccine (DTaP-Hib): The main components are acellular diphtheria-tetanus and Haemophilus influenzae type b conjugate vaccine (DTaP-Hib) (co-purification process) and Haemophilus influenzae type b conjugate vaccine. For the prevention of whooping cough, diphtheria, tetanus and invasive diseases caused by Haemophilus influenzae type b.

•Adsorbed acellular DPT vaccine inactivated poliomyelitis and Haemophilus influenzae type b (conjugated) combination vaccine (DTaP-IPV//Hib): composed of adsorbed acellular DTP inactivated poliomyelitis combined vaccine, containing adsorbed on It consists of diphtheria toxoid, tetanus toxoid, two purified pertussis antigens (PT and FHA) and three types of poliovirus and Haemophilus influenzae type b conjugate vaccines on aluminum hydroxide. For the prevention of whooping cough, diphtheria, tetanus, poliomyelitis and invasive infections caused by Haemophilus influenzae type b.

•Adsorbed diphtheria-tetanus combined vaccine (DT): It is made from the original solution of diphtheria toxoid and the original solution of tetanus toxoid with aluminum hydroxide adjuvant. It is used for booster immunization against diphtheria and tetanus in children who have been fully immunized with adsorbed pertussis, diphtheria and tetanus combined vaccine.

•The adsorbed tetanus vaccine is made by using Clostridium tetanus, culturing the toxin in a suitable culture medium, detoxifying and refining it with formaldehyde, and adding aluminum hydroxide adjuvant. Used to prevent tetanus.

Among them, DTaP and DT are immunization program vaccines, and DTaP-Hib, DTaP-IPV//Hib and adsorbed tetanus vaccine are non-immunization program vaccines.

◆Vaccine technology

•Strain activation (the production strain used in China is L58 strain)

•To cultivate toxin production, deep culture in culture tanks is used. Adding organelles to the culture medium will reduce the level of toxin production. In addition, it must be discharged through ventilation. hydrogen sulfide and carbon dioxide)

•Formaldehyde heating detoxification (the method currently used is 0.36% formaldehyde, pH neutral, 37C detoxification for 30 days

•Concentration and purification (concentration by ultrafiltration, sulfuric acid precipitation)

•Sterilization filtration (remove bacteria through 0.22um microporous membrane filtration)

•Adsorption and purification of tetanus toxin (adsorption with gaseous alumina)