The genes for major glycoprotein antigens E and NS1 of the tick-borne
encephalitis virus (TBEV) were recloned in an eukaryotic expression ve
ctor pSVK3. The resulting pSVK3-ENS1 plasmid was characterized by sequ
encing and restriction enzyme analysis. To test the protective effect
of gene immunization, BALB/c mice were immunized with 80-100 mu g of p
urified pSVK3-ENS1 DNA five times and injected with 100 LD50 of the TB
EV Sof'in strain one week after the last immunization. Immunized mice
remained healthy for the observation period, while all control mice ma
nifested the pathology and 42.9% of them died.