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Published on: February 27, 2019
Development of a Monocyte Activation Test as an Alternative to the Rabbit Pyrogen Test for Mono- and Multi-Component
Danielle Carson1, Sophie Myhill1, Elena Palmieri2
1The National Institute for Biological Standards and Control (NIBSC), South Mimms EN6 3QG, UK.
Abstract:
Generalised modules for membrane antigens (GMMA)-based vaccines comprise the outer membrane from genetically modified Gram-negative bacteria containing membrane proteins, phospholipids and lipopolysaccharides. Some lipoproteins and lipopolysaccharides are pyrogens; thus, GMMA-based vaccines are intrinsically pyrogenic. It is important to control the pyrogenic content of biological medicines, including vaccines, to prevent adverse reactions such as febrile responses. The rabbit pyrogen test (RPT) and bacterial endotoxin test (BET) are the most commonly employed safety assays used to detect pyrogens. However, both tests are tailored for detecting pyrogenic contaminants and have considerable limitations when measuring the pyrogen content of inherently pyrogenic products. We report the adaptation of the monocyte activation test (MAT) as an alternative to the RPT for monitoring the pyrogenicity of Shigella GMMA-based vaccines. The European Pharmacopoeia endorses three MAT methods (A-C). Of these, method C, the reference lot comparison test, was identified as the most suitable. This method was evaluated with different reference materials to ensure parallelism and consistency for a mono- and multi-component Shigella GMMA vaccine. We demonstrate the drug substance as a promising reference material for safety testing of the matched drug product. Our results support the implementation of MAT as an alternative to the RPT and use of the defined parameters can be extended to GMMA-based vaccines currently in development, aiding vaccine batch release.
Insights
Generalised modules for membrane antigens (GMMA)-based vaccines are inherently pyrogenic. The monocyte activation test (MAT) is adapted as a superior alternative to traditional pyrogen tests for GMMA vaccine safety.
Area of Science:
- Vaccinology
- Immunology
- Microbiology
Background:
- Generalised modules for membrane antigens (GMMA) vaccines are derived from Gram-negative bacteria and contain pyrogenic components.
- Traditional pyrogen tests like the rabbit pyrogen test (RPT) and bacterial endotoxin test (BET) have limitations for inherently pyrogenic products.
- Controlling pyrogenicity is crucial for vaccine safety to prevent adverse reactions like fever.
Purpose of the Study:
- To adapt and validate the monocyte activation test (MAT) as an alternative to the RPT for pyrogenicity assessment of *Shigella* GMMA-based vaccines.
- To evaluate the suitability of different MAT methods, specifically focusing on the reference lot comparison test (Method C).
- To establish the utility of drug substance as a reference material for safety testing of GMMA drug products.
Main Methods:
- Adaptation of the European Pharmacopoeia's monocyte activation test (MAT) Method C (reference lot comparison test).
- Evaluation of MAT Method C using reference materials for mono- and multi-component *Shigella* GMMA vaccines.
- Demonstration of drug substance as a suitable reference material for safety testing.
Main Results:
- MAT Method C was successfully adapted and validated for monitoring pyrogenicity in *Shigella* GMMA vaccines.
- Parallelism and consistency were achieved using defined reference materials.
- The drug substance proved to be a reliable reference material for the matched drug product.
Conclusions:
- The monocyte activation test (MAT) is a suitable alternative to the rabbit pyrogen test (RPT) for assessing the pyrogenicity of GMMA-based vaccines.
- The validated MAT method and use of drug substance as reference material can aid in the batch release of GMMA vaccines.
- This approach can be extended to other GMMA-based vaccines in development, improving safety testing protocols.
