Comparison of the protective efficacy of naked DNA, DNA-based Sindbis replicon, and packaged Sindbis replicon vectors expressing hantavirus structural genes in hamsters

Seoul virus (SEOV) is a member of the Hantavirus genus (family Bunyaviridae ) and an etiological agent of hemorrhagic fever with renal syndrome. The me dium (M) and small (S) gene segments of SEOV encode the viral envelope glyc oproteins and nucleocapsid protein, respectively. We compared the immunogen icity and protective efficacy of naked DNA (pWRG7077), DNA-based Sindbis re plicon (pSIN2.5), and packaged Sindbis replicon vectors (pSINrep5), contain ing either the M or S gene segment of SEOV in Syrian hamsters. All of the v ectors elicited an anti-SEOV immune response to the expressed SEOV gene pro ducts. Vaccinated hamsters were challenged with SEOV and monitored for evid ence of infection. Protection from infection was strongly associated with M -gene vaccination. A small number of S-gene-vaccinated animals also were pr otected. Hamsters vaccinated with the pWRG7077 vector expressing the M gene demonstrated the most consistent protection from SEOV infection and also w ere protected from heterologous hantavirus (Hantaan virus) infection, (C) 1 999 Academic Press.