Establishment of detection antibodies BRRs batch 4 for in vitro potency assay of hepatitis A vaccines by ELISA.

The European Pharmacopoeia (Ph. Eur.) standard ELISA method for determination of antigen content of hepatitis A vaccines (HAV) requires specific coating and detection Biological Reference Reagents (BRRs). The 3rd batch of detection antibodies BRRs was established in 2015 for use in conjunction with the Ph. Eur. general chapter 2.7.14 'Assay of hepatitis A vaccine'. Stocks of these BRRs were running low and therefore the European Directorate for the Quality of Medicines & HealthCare (EDQM) organised a collaborative study to qualify replacement batches. The candidate BRR antibodies batch 4 were prepared under appropriate conditions from starting materials similar to previous batches to ensure continuity. During the collaborative study, the new batches of antibodies were compared to previous batches of BRRs. Results confirmed that they were suitable to be used for the intended purpose, and could be used at the same final concentrations as the previous batch, i.e. 1:500 for the primary antibody and 1:400 for the conjugated secondary antibody. They were adopted in June 2017 by the Ph. Eur. Commission as Hepatitis A virus primary detection antibody BRR batch 4 and Conjugated secondary detection antibody BRR batch 4, respectively. They are available from the EDQM as Hepatitis A vaccine ELISA detection antibodies set BRR batch 4.