Application of β-propiolactone in HFRS vaccine

Objective To study the optimal inactivated condition of β-propiolactone(BPL) on preparation of hemorrhagic fever with renal syndrome(HFRS)bivalent purified vaccine(vero cells derived).Methods The HFRS bivalent purified vaccine was treated with different final concentrations and different time respectively.Residual infectivity was determimed by standard viral proliferation assay on tissue culture cells.Using high performance liquid chromatography(HPLC),the optimal condition of hydrolyssi of bpl was analyzed and the residual contents of BPL in 3 batches of HFRS bivalent purified and inactivated vaccine were measured.Rabbits immunized with the 3 batches of HFRS bivalent purified and inactivated vaccine were detected the neutralizing antibody titers of sera at 4 weeks after 2 times of immunization.Results The HFRS bivalent purified vaccines treated with the final concentration of 1∶2?000 and 1∶4?000 of BPL for 24 hours were inactivated completely.Under the condition of 37?℃ water bath,the content of BPL in HFRS vaccine decreased gradually along with the prolongation of time and disappeared completely 2 hous later.Rabbits immunized with the 3 batches of HFRS bivalent purified and inactivated vaccine showed 100% sera conversion and the neutralizing antibody titers of sera against hantaan virus(HTN) and seoul virus(SEO) reached 1∶20.Conclusion It was feasible and secure for inactivation of HFRS bivalent purified vaccine(vero cells derived)with the final concentration of 1∶4?000 of BPL under the conditions of 4?℃ for 24 hours and then 37?℃ water bathing for 2 hours.The HFRS bivalent purified vaccine inactivated with BPL possessed good immunogenicity.