Toxoid

Toxoid form a subgroup of inactivated vaccines. They contain as active ingredient and toxoids are used in active vaccination. Toxoids are detoxified toxins, which by special methods which are responsible for the toxicity properties were destroyed, in which the antigenic effect is maintained. Toxoid are widely used in the prophylaxis of tetanus and diphtheria.

Production

Detoxification

The production of toxoid vaccines begins with a bacterial culture of pathogenic bacteria Clostridium tetani or Corynebacterium diphtheriae. These bacteria produce exotoxins, which are secreted into the culture medium. These toxins are produced by sterile filtration and treated to detoxify for several days at 30-40 ° C and the formaldehyde solution. Under these conditions respond free amino groups in the protein side chains of the toxins with formaldehyde to form azomethine groups. This modification causes for example tetanospasmin can no longer bind to gangliosides, and thus has lost its toxic effect.

Purification and formulation

The Rohtoxoid thus produced is treated with standard methods of protein purification to a high purity toxoid. Among other things, also the harmful formaldehyde is removed; Pharmacopoeia regulations require less than 0.02 % formaldehyde in the vaccine. The purified toxoid must also be checked for the presence of unwanted toxoid dimers or polymers; these do not induce immunity to the toxin.

Applying the toxoid is adsorbed is usually of aluminum salts such as aluminum hydroxide; This enhances the adjuvant the immune response to the toxoid.

Batch testing

Prior to releasing each batch of newly manufactured Toxoidimpfstoffes in animal studies for efficacy and safety must be checked. This house guinea pigs are typically used, which should be immune after vaccination against the administration of a dose of the poisonous toxin. In addition, animals may show even after a dose of vaccine, no specific toxicity; , vaccination with tetanus toxoid vaccine, animals may show no signs of tetanus disease within six weeks.

Application

Toxoid vaccines are rarely as individual vaccines for use. Chance is tetanus toxoid vaccine ( Tetanol ®) used for simultaneous vaccination with tetanus immunoglobulin if injured at the vaccination is unclear or does not exist, but even in these cases, diphtheria and tetanus combination vaccines (Td ) is recommended. Standard are the Td vaccines in combination booster vaccinations in adults; this should be carried out every ten years. For primary immunization in infants and children after vaccination schedule are preferably different combination vaccines such as DTP vaccine or a hexavalent vaccine used. Toxoid vaccines are well tolerated and may for example be used in pregnant women. The most common side effects include pain, swelling and induration at the injection site, and muscle pain.

Historical

The toxoid vaccines (also called anatoxins ) were developed in 1923 by the French veterinarian Gaston Ramon. The toxoid vaccines are thus the oldest still routinely conventional vaccines.

• Immunology
• Vaccine
• Medicine
• ATC J07