The current hepatitis A vaccine (HAV), inactivated, non-adsorbed, European Pharmacopoeia (Ph. Eur.) Biological Reference Preparation (BRP) is used for the in vitro potency assay of HAVas prescribed by the Ph. Eur. general chapter 2.7.14 Assay of hepatitis A vaccine. This reference preparation was calibrated in 2008 through an international collaborative study and was assigneda potency of 12 IU/mL. During use of this BRP it appeared to be inapplicable in certain cases due to a low nominal antigen content. Consequently, the European Directorate for the Qualityof Medicines and HealthCare (EDQM) established replacement batches for this BRP, calibrated against the 1st WHO International Standard (IS) for HAV (inactivated), using the standard in vitroELISA (enzyme-linked immunosorbent assay) method validated previously. The results of the study showed that the candidate BRPs were suitable for the intended purpose, and following completionof the study, they were adopted in November 2014 by the Ph. Eur. Commission as HAV (inactivated, non-adsorbed) BRP batches 2 and 3, with an assigned potency of 1350 IU/mL, for in vitro antigencontent determination by ELISA. As the amount of material in each vial largely exceeds the amount required for the performance of a single assay, the BRPs are to be aliquoted by users as single-usealiquots and refrozen below -50 °C prior to their use as reference preparations.