Harmonization of Vaccine Ligand Binding Assays Validation.

The urgency and importance of organizing a global effort to harmonize clinical assay validation specific to the vaccine industry was identified during the drafting of the 2020 White Paper in Bioanalysis due to the lack of clarity and regulatory guidance/guidelines in vaccine immunoassay validation. Indeed, the Workshop on Recent Issues in Bioanalysis (WRIB) issues the White Paper in Bioanalysis yearly, which is one of the high-profile articles of the Bioanalysis Journal focused on detailed discussions and recommendations on vaccine assay validation. Since 2017, participation in the WRIB working groups by vaccine assay validation experts and regulators has rapidly increased due to its unique format where industry leaders and regulators can meet and exchange ideas on topics of interest to both groups. In early 2021, Vaccine manufacturers approached WRIB for sponsoring/supporting the authorship and publication of an overarching vaccine assay validation document based on the 2017-2020 discussions and consensus starting from immunogenicity assays first and followed by future papers on molecular and cell-based assay validation. Using industry and WRIB vaccine network, a vaccine immunogenicity assay validation working group was assembled consisting of 16 companies. The work on the first white paper started officially in April 2021 focusing on Vaccine LBA Validation (Part 1), and the drafting of Vaccine LBA Development (Part 2) and Vaccine LBA Monitoring & Transfer (Part 3) are presently ongoing and expected to be published shortly after this paper. Moreover, recommendations on Vaccine Cell-Based Assays Validation (ELISpot and Flow cytometry) and Vaccine Molecular Assays Validation (PCR, NGS, NanoString) are also on the WRIB publications agenda and the drafting is planned to start in mid-2024. For too long, vaccine scientists have not had a clear validation guidance for clinical vaccine immunogenicity assays. We hope that this common effort will help close this regulatory gap.