Assessing the stability-indicating properties of alternative potency assays for inactivated influenza vaccine.

Determination of the potency of a vaccine is critical to ensuring that an appropriate dose is delivered, lot-to-lot consistency is maintained, and that the formulation is stable over the life of the vaccine. The potency of inactivated influenza vaccines is determined routinely by the Single Radial Immunodiffusion (SRID) assay. A number of alternative potency assays have been proposed and have been under evaluation in recent years.

Development of an ELISA-Based Potency Assay for Inactivated Influenza Vaccines Using Cross-Reactive Nanobodies.

Inactivated vaccines are the main influenza vaccines used today; these are usually presented as split (detergent-disrupted) or subunit vaccines, while whole-virus-inactivated influenza vaccines are rare. The single radial immune diffusion (SRD) assay has been used as the gold standard potency assay for inactivated influenza vaccines for decades; however, more recently, various alternative potency assays have been proposed. A new potency test should be able to measure the amount of functional antigen in the vaccine, which in the case of influenza vaccines is the haemagglutinin (HA) protein.

The influence of the closure format on the storage stability and moisture content of freeze-dried influenza antigen.

Low moisture content is seen as crucial to achieving long term stability of freeze dried biologics and reference materials. Highly hygroscopic freeze-dried material are susceptible to moisture ingress over time which can lead to degradation and loss of biological potency. This study compared vials with unprocessed stoppers, vials with vacuum-oven dried stoppers and glass ampoules in order to determine the superior long term storage format in terms of moisture ingress and potency.

Site-specific PEGylation at histidine tags.

The efficacy of protein-based medicines can be compromised by their rapid clearance from the blood circulatory system. Achieving optimal pharmacokinetics is a key requirement for the successful development of safe protein-based medicines. Protein PEGylation is a clinically proven strategy to increase the circulation half-life of protein-based medicines.