In vitro potency assay for hepatitis A vaccines: development of a unique economical test

Prior to the official release of each Hepatitis A vaccine lot to the market, a quality control performed by a National Control Authority requires an in vivo or an in vitro potency assay. At the beginning of our work, no standardised in vitro test common to all hepatitis A vaccines was available for both manufacturers and National Control Laboratories. In this study, a unique polyvalent enzyme-linked immunosorbent assay (ELISA) method was developed to appraise all commercially available HAV vaccines. After comparing a direct and an indirect sandwich method with commercial antibodies, the indirect assay was selected and an evaluation of sensitivity, linearity, accuracy and precision was performed before being applied to HAV antigen determination from four different manufacturers. The results are satisfactory and incline us to use routinely this method to release Hepatitis A vaccines.