Recombinant Hansenula Hepatitis B Vaccine Experiment Potency Testing

The adr Recombinant Hansenula polymorpha (HP) Yeast Hepatitis B vaccine (rHP-HB vaccine) is a new genetic engineering vaccine. Adr subtype HBsAg, the vital component, is expressed by recombinant HP yeast. During the development of the adr rHP-HB vaccine, the in vivo mouse ED₅₀ test (reflecting the ability of inducing special antibody, immunogenicity) and in vitro relative potency (RP) test (reflecting the ability of HBsAg combining with special antibody, reactionogenicity) are used to detect the potency of rHP-HB vaccine. The correlation or consistency between two methods was evaluated and discussed, and important results were obtained. It can provide reference for establishment of methods on release test for laboratory potency of the vaccine.We immunized BALB/c mice and NIH mice with test rHP-HB vaccines, National Reference vaccine and laboratory reference of rHP-HB vaccine in order to detect ED₅₀. The result of BALB/c mice ED₅₀ is more sensitive and stable than that of NIH mice ED₅₀ in a few trials. We calculated all the ED₅₀ values of BALB/c mice and NIH mice in many tests by statistical method, there is no significant difference (P > 0.05) between two groups. It can be concluded that either strain mouse can be taken as the laboratory animal for detecting the ED₅₀ of the vaccine in study.Taking the National Reference vaccine and the laboratory reference vaccine as the standard, using the Enzyme-linked immunosorbent assay (ELISA) and the Electro-chemiluminescence immunoassay (ECLIA), the RPs of different batches of test rHP-HB vaccines were detected, and two methods and two references were compared, respectively. The results demonstrate that the accuracy and precision of ECLIA is better than that of ELISA in detecting RP, and this means that ECLIA could be a primary method for detecting RP of rHP-HB vaccines. Statistical analysis was conducted in comparison of RP values from different batches of rHP-HB vaccines by ECLIA, and the result showed that there is a significant difference (P <0.05) between RP results of the two references.Through analyzing all results of in vitro (RP) test and in vivo (ED₅₀) test, the trends show that the laboratory potencies are consistent with each other by the two methods, but there was no direct correlation between results of RP test and ED₅₀ test. In accelerated stability tests, along with the thermal-treating (37°C) time, both the RP values and ED₅₀ values decrease, the CV of RP values lies between 0.9% and 5.8%, but the CV of ED₅₀ values is higher, which lies between 10.6% and 45.1%, the statistical analysis of the results of references and samples show that the variation trend of RP value is consistent with the ED₅₀ value. Compared with ED₅₀ test, the RP test has better accuracy, better precision and less test time, which can reflect the potency of reference vaccines and test vaccines. Conclusively, the result of RP test is generally consistent with that of animal experiments, so the RP test can be used as the release test for the quality control of the developing rHP-HB vaccine.