Vaccine Characterisation, formulation and adjuvantisation (CQAs)
- The analytical characterisation of vaccines is essential for both process development and process changes is required at a later stage – but also can help to reduce QC costs. It requires an overall assessment from a family of assays designed to check the physical, chemical, biological and/or immunological characteristics of the vaccine in question.
- Appearance, purity, primary, secondary and tertiary structure assays may be required to characterise the vaccine in questions. In addition, thermostability and chemical stability in excipients may also be assessed in these early stages to assist with candidate selection.
- An additional consideration is the use of preservatives if the vaccine is intended for multi-dose presentations, as some preservatives may interfere with the antigen.
- Should the final vaccine require an adjuvant, it may be possible to consider formulation of the bulk antigen with an adjuvant as well, though this should link back to the Target Product Profile as defined at the start of this process.
- It may not be possible to conduct all these steps at this point due to limited process knowledge and purified bulk antigen – however a general scheme that could be used it to conduct the analytical characterisation of the antigen. This could then followed by determining the physiochemical stability and degradation pathways of the antigen. This would allow for formulation of the bulk antigens and the adjuvanted drug product.
- The bottleneck is in selecting the most appropriate assays and developing an understanding of the degradation pathways and formulation requirements. As such, this can be an on going process until clinical development.