Validation of an in-vitro method for Hepatitis B vaccine potency assay: specification setting

Production batches of the Hepatitis B vaccine should be tested by the National Control Laboratory (NCL) before being released to the market, in terms of their potency. This can be done either by means of the mouse immunogenicity (in-vivo) method, which is a time-consuming and labor intensive process, or by an in-vitro method with acceptable analytical performance and with specifications determined based on the results obtained from testing some production batches of the vaccine with proven efficacy. Here we report the feasibility of using and validation of a commercial enzyme-linked immunosorbent assay (ELISA) kit replacing the manufacturer's method and setting of different specification for potency of the particular vaccine.

For the in-vitro potency assay of the Hepavax-Gene®, produced by Berna Biotech Korea Corp, a commercial ELISA kit for hepatitis B surface antigen (HBsAg) quantitation (Hepanostika® HBsAg Ultra from Biomerieux) was used to determine the relative potency. Validation parameters were evaluated following the International Conference on Harmonization (ICH) guidelines. Specification of the vaccine potency was determined based on the results generated by the commercial ELISA kit. Some batches were tested by in-vivo method as well.

It was confirmed that the ELISA kit, when used for vaccine potency testing, meets the criteria for accuracy (80% to 110% recovery), precision (repeatability, with a CV% less than 5%; and intermediate precision, with a CV% less than 10%) and Linearity (r2> 98%), as well as being able to detect HBsAg specifically. Specification of the in-vitro method was also determined as having a relative potency of >50%.

The Hepanostika® HBsAg Ultra kit from Biomerieux can be used to determine the relative potency of the Hepavax-Gene® Hep B vaccine as an alternative to the manufacturer's method and with different specifications.