ABSTRACT
<p><b>OBJECTIVE</b>To adapt the candidate strains of hemorrhagic fever with renal syndrome (HFRS) purified vaccine to Vero cells and to study their antigenicity and immunogenicity.</p><p><b>METHODS</b>The viral strains H8207 (Hantaan virus, HTN) and Y86013 (Seoul virus, SEO) were continuously propagated in Vero cell by the terminal dilution method and studied the characteristics of virus multiplication, viral titers and the amounts of virus antigen after serial passages. Three batches of crude monovalent inactivated vaccine were developed using the different passages of these 2 viral strains.</p><p><b>RESULTS</b>The strains H8207 and Y86013 adapted to Vero cells and stably grew on the cells with high titers. Rabbits immunized with the crude vaccines of H8207 and Y86013 showed 100% sero-conversion and the neutralizing antibody titers of the rabbit immune sera reached 1?10 at 4 weeks after 2 times of immunization.</p><p><b>CONCLUSIONS</b>The results suggest that these 2 candidate strains had adapted to Vero cells, possessed high titers and good immunogenicity and be feasible to prepare the HFRS purified vaccine in Vero cells.</p>