Physicochemical and immunochemical assays for monitoring consistent production of tetanus toxoid

Biologicals. 2013 Jul;41(4):231-7. doi: 10.1016/j.biologicals.2013.05.001. Epub 2013 May 30.

Abstract

The detoxification of tetanus toxin by formaldehyde is a crucial step in the production of tetanus toxoid. The inactivation results in chemically modified proteins and it determines largely the ultimate efficacy and safety of the vaccine. Currently, the quality of tetanus toxoid lots is evaluated in potency and safety tests performed in animals. As a possible alternative, this article describes a panel of in vitro methods, which provides detailed information about the quality of tetanus toxoid. Ten experimental lots of tetanus toxoid were prepared using increasing concentrations of formaldehyde and glycine to obtain tetanus toxoids having differences in antigenicity, immunogenicity, residual toxicity and protein structure. The structural properties of each individual toxoid were determined using immunochemical and physicochemical methods, including biosensor analysis, ELISA, circular dichroism, TNBS assay, differential scanning calorimetry, fluorescence and SDS-PAGE. The quality of a tetanus toxoid lot can be assessed by these set of analytical techniques. Based on antigenicity, immunogenicity and residual toxicity data, criteria are formulated that tetanus toxoids lot have to meet in order to have a high quality. The in vitro methods are a valuable selection of techniques for monitoring consistency of production of tetanus toxoid, especially for the detoxification process of tetanus toxin.

Keywords: Immunochemical techniques; Physicochemical techniques; Potency; Structural characterization; Tetanus toxoid; Vaccine; formaldehyde.

MeSH terms

  • Animals
  • Biosensing Techniques / methods
  • Female
  • Formaldehyde / chemistry*
  • Quality Control
  • Tetanus Toxin / chemistry*
  • Tetanus Toxin / pharmacology*
  • Tetanus Toxoid / adverse effects
  • Tetanus Toxoid / chemistry*
  • Tetanus Toxoid / pharmacology*

Substances

  • Tetanus Toxin
  • Tetanus Toxoid
  • Formaldehyde