Independent control of COVID-19 vaccines by EU Official Control Authority Batch Release: challenges, strengths and successes.

Vaccines have been a key tool in stemming the tide of the COVID-19 pandemic. The rapid development of effective vaccines against COVID-19, together with their regulatory approval and wide scale distribution has been achieved in an impressively short period thanks to the intense efforts of many. In parallel to vaccine development, the EU considered it important to prepare for the independent control of the COVID-19 vaccines, including testing, to help ensure that only vaccines that comply with the approved quality requirements reach the public and to help improve/increase public confidence in the vaccines. The existing EU Official Control Authority Batch Release (OCABR) system, co-ordinated by the European Directorate for the Quality of Medicines and HealthCare (EDQM), was able to effectively respond to the need, through rapid co-ordination, work-sharing, advance planning and early interaction with manufacturers, the Coalition for Epidemic Preparedness Innovation (CEPI) and regulatory authorities. The Official Medicines Control Laboratories (OMCLs) involved in the OCABR activity, using the strength of the established system in the OCABR network and adaptations to the crisis conditions, were ready to release the first COVID-19 vaccine batches, after protocol review and testing, at the time of the conditional marketing authorisation for each of the COVID-19 vaccines, with no delay for batches reaching the public. Thanks to the dedication of resources by the EU and national authorities as well as by the EDQM, this was done without impacting the release of the other vaccines and human blood and plasma derived medicinal products, essential for public health. Transparency and communication of practices were important factors to support reliance on the OCABR outcome in non-EU countries, with the goal to improve access to vaccines in Europe and beyond. An overview of the process, legal background, challenges and successes of OCABR for COVID-19 vaccines as well as a look at the international perspective and lessons learned is provided.

Estimating the Reliability of Low-Abundant Signals and Limited Replicate Measurements through MS2 Peak Area in SWATH.

Sequential windows acquisition of all theoretical fragment ions mass spectrometry (SWATH-MS) provides large-scale protein quantification with high accuracy and selectivity. Nevertheless, reliable quantification of low-abundant signals in complex samples remains challenging, as recently illustrated in a multicenter benchmark study of different label-free software tools. Here, the SWATH Replicates Analysis 2.0 template from Sciex is used to highlight that the relationship between the MS2 peak area and the variability can be described by a function. This functional relationship appears to be largely insensitive to variation in samples or acquisition conditions, suggesting a device-intrinsic property. By using a power regression, it is shown that the MS2 peak area can be used to predict the quantification repeatability without relying on replicate injections, thus contributing to high-throughput confident quantification of low-abundant signals with SWATH-MS.

An application of mass spectrometry for quality control of biologicals: Highly sensitive profiling of plasma residuals in human plasma-derived immunoglobulin.

Thromboembolic events (TEE) associated to trace amounts of plasmatic activated coagulation factor XI (FXIa) in administrated immunoglobulin (Ig) have recently raised concerns and hence there is a need for highly sensitive profiling of residual plasma source proteins. This study aims to consider LC-ESI-QTOF data-dependent acquisition in combination with sample fractionation for this purpose. Sample fractionation proved mandatory to enable identification of plasma residuals. Two approaches were compared: Ig depletion with protein G - protein A affinity chromatography and low-abundant protein enrichment with a combinatorial peptide ligand library (ProteoMiner™, Bio-Rad). The latter allowed a higher number of identifications. Highly sensitive detection of prothrombotic FXIa was assessed with confident identification of a 1ng/mg spike. Moreover, different residuals compositions were profiled for various commercial Ig products. Using a quantitative label free analysis, a TEE-positive Ig batch was distinguished from other regular Ig products, with increased levels of FXIa but also other unique proteins. This could have prevented the recently observed TEE problems with Ig. The method is a convenient tool to better characterize Ig products after any plasma pool or manufacture process change, gaining insights in the product quality profile without any prior information required. BIOLOGICAL SIGNIFICANCE: This study characterized residual plasma proteins in Ig products, using bottom-up LC-MS/MS with conventional data-dependent acquisition, preceded by sample fractionation. Without any prior information or target-specific development, >30 proteins were identified in a commercial Ig product. Quality control relevance was demonstrated with the identification of FXIa spiked at 1ng/mg in Ig, which is below the minimal thrombotic dose of 3ng/mg observed in an in vivo model. Relative label-free quantitation highlighted significant differences in normalized abundances of residual proteins between Ig products. A TEE-positive batch was distinguished by unique profile of residual proteins, including FXIa but also various blood stream-regulator proteins (fibrinogen, angiotensinogen, antithrombin-III, complement component C8, …). Those results emphasize that MS screening is a relevant first-line test to prevent any undesired concentration of plasma impurities after a plasma pool or manufacturing process change.

Assessing the potency of oral polio vaccine kept outside of the cold chain during a national immunization campaign in Chad.

This study is the first systematic documentation of the potency of monovalent oral polio vaccine type 3 (mOPV3) kept at ambient temperatures during a polio immunization campaign in Chad. During the study test vials were exposed to temperatures of up to 47.1 °C, and kept outside of the 2-8 °C range for a maximum of 86.9 hours. Post-campaign laboratory testing confirmed that the test vials were still potent, and in conformity with the defined release specifications. Further, the Vaccine Vial Monitors performed as expected, giving an early warning indication of when cumulative exposure to heat reached levels that may have negatively affected the vaccine's potency. This study provides proof-of-concept evidence that certain types of OPV remain potent and thus can be kept, for limited periods of time, as well as administered at ambient temperatures.